Data from the

NATIONAL HEALTH SURVEY

U.S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE

Public Health Service

Series 11

Number 145

Hearinglevelsof Youths

12=17Years

UnitedStates

Distribution of monaural hearing levels of youths 12-17 years at

frequencies of 250, 500, 1000, 2000, 3000, 4000, 6000, and

8000 Hertz as determined in individual air-conduction tests, by

age, sex, race, geographic region, size of place of residence,

family income, and education of parent.

DHEW Publication No. (HRA) 75-1627

Health Resources Administration

National Center for Health Statistics

Rockville, Md. January 1975
!

Series 11 reports present findings from the National Health Examination Survey, which

obtains data through direct examination, tests, and measurements of samples of the U.S.

,population. Reports 1 through 38 relate to the adult program, Cycle I of the Health

Examination Survey. The present report is one of a number of reports of findings from the

children and youth programs, Cycles II and III of the Health Examination Survey. These

latter reports from Cycles II and III are being published in Series 11 but are numbered

consecutively beginning with 101. It is hoped this will guide users to the data in which they

I

are interested.

,

Library of congress Cataloging in Publication Data

Robertsj Jean

Hearing levels of youths 12-17 years, United States.

(National Center for Health Statistics. Data from the National Health Survey, series 11,

no. 145) (DHEW publication no. (HRA) 75-1627)

Bibliography: p.

1. Hearing-United States–Statistics. 2. Youth–United States-Health and hygiene–

Statistics. 3. United States, Statistics, Medical. I. Ahuja, Elizabeth, joint author. II. Title. HI.

Series: United States. National Center for Health Statistics. Vital and health statistics. Series

11: Data from the National Health Survey. Data from the health examination survey, no.

145. IV. Series: United States. Dept. of Health, Education, and Welfare. DHEW publication

no. (HRA) 75-1627. [DNLM: 1. Hearing-In adolescence. 2. Hearing tests-In adolescence

W2A N148vk no. 143]

RA407.3.A347 no. 145 [RF294] 312’.0973s [312’.6] ISBN 0-8406 -0024-0 74-11318
NATIONAL CENTER FOR HEALTH STATISTICS

EDWARD B. PERRIN, Ph. D., -Director

PHILIP S. LAWRENCE, SC.D., Depu ty Director

GAIL F. FISHER Associate Director for the Cooperative Health Statistics System

ELIJAH L. WHITE, Associate Dire@ torfor Data Systems

IWAO M. MORIYAMA, Ph.D., Associate Director for International Statistics

EDWARD E. MINTY, Associizte Director for Management

ROBERT A. ISR4EL, Associate Director for Operations

QUENTIN R. REMEIN, Associate Director for Program Deuebpment

ALICE HAYWOOD, Information Officer

DIVISION OF HEALTH EXAMINATION STATISTICS

ARTHUR J. McDOWELL, Director

PETER V. V. HAMILL, M.D., Medical Advisor, ChiZdren and Youths l%o~ams

JEAN ROBERTS, Chief, Medical Statistics Section

HENRY W. MILLER, Chiefi Operations Branch

COOPERATION OF THE BUREAU OF THE CENSUS

In accordance with specifications established by the National

Health Survey, the Bureau of the Census, under a contractual

agreement, participated in the design and selection of the sample,

and carried out the first stage of the field interviewing and certain

parts of the statistical processing.

VitaI and Health Statistics-Series 11-No. 145

DHEW Publication No. (HRA)75-1 627

Library of Congress Catalog (%-d Number 74-11318
CONTENTS

Page

Introduction .................................................................................................... 1

Hearing Measurement and Related ENT Examination .................................... 3

Acoustical Environment .............................................................................. 4

Audiometer Calibration and Other Aspects of Quality Control ................. 5

Findings ..........................................................................................................

Age and Sex ...............................................................................................

Race ............................................................................................................

Region ........................................................................................................

Size of Place of Residence ...........................................................................

Family Income ...........................................................................................

Education of Parent ...................................................................................

Estimated Hearing Levels for Speech ........................................................

7

11

12

14

15

15

17

18

Comparison with Previous Studies ................................................................ 21

Summary ........................................................................................................ 22

References ...................................................................................................... 24

List of Detailed Tables ................................................................................... 25

Appendix I. Statistical Notes ........................................................................ 76

The Survey Design ...................................................................................... 76

Reliabilityy ................................................................................................... 77

Sampling and Measurement Error ............................................................. 79

Small Numbers ........................................................................................... 79

Appendix II. Demographic and Socioeconomic Terms .................................. 81

Appendix III. Recording Form ....................................................................... 83

Appendix IV. Standards for Reference (Audiometric) Zero ......................... 84

...

m
SYMBOLS

Data not available --------------------------------------- ---

Category not applicable ------------------------------ . . .

Quantity zero --------------------------------------------- -

Quantity morethan Obutless than0.05---- 0.0

Figure does not meet standards of

reliability or precision ---------------------------- *
HEARING LEVELS OF U.S. YOUTHS

12-17YEARS

Jean Roberts and Elizabeth M. Ahuja, Division of Health -Examination Statistics

INTRODUCTION

This report gives national estimates of the

hearing levels of youths 12L17 years of age in the

civilian noninstitutionalized population of the

LJnited States. These are based on individual

monaural pure-tone audiometric test results, at

eight frequencies obtained in the Health Examination Survey of 1966-70 for a national probability sample representative of the 22.7 million

youths in that segment of the population.

Findings have been analyzed with respect to age,

sex, race, geographic region, size of place of residcncc, family income, and education of parent.

The Health Examination Survey is one of the

major programs of the National Center for Health

Statistics, authorized through the National Health

Survey Act of 1956 by the 84th Congress as a

continuing Public Health Service function to

determine the health status of the population. 1

In the National Center for Health Statistics,

the principal health survey programs include the

Ikdth Examination, Health Interview, Health

Manpower and Facilities, and Health Resources

Utilization. The Health Interview Survey, which

collects health information from samples of

people by household interview, studies primarily

the impact of known illness and disability on the

lives of people. The Health Manpower and FaeiIities programs obtain information through surveys

oi hospltak, nursing homes, and other resident

institutions, and the entire range of personnel in

the healt+ occupations. The Health Resources

‘Ut~lizafion surveys obtak information on the

extent of health facility and service utilization.

The “Health Examination Survey coIlects data

through direct physical examinations, tests, and

measurements performed on scientifically selected nationwide probability samples of the

population. This system, in addition to providing

the most efficient way of obtaining actual diagnostic data on the prevalence of specified medically defined illness, is the only one of the survey

programs to secure information on unrecognized

or undiagnosed conditions as well as a variety

of physical, physiological, and psychological

measures within the population. In conjunction

with the examination, medical history, demographic and socioeconomic data were obtained

on the sample population under study with

which the examination findings for these persons may be interrelated.

The HeaIth Examination Survey is planned as

a series of separate programs called “cycles.”

Each cycle is Iimited to specific aspeets of health

within specific segments of the U.S. population.

The first cycle in 1960-62 was designed primarily

to provide data on the prevalence of certain

chronic diseases and on the distribution of

various physical and physiological measures in a

defined adult population.z ~3

The target population for the second cycle in

1963-65 was the non institutionalized children

6-11 years of age. For it the examination was
focused primarily on health

growth and development.Q!s

factors related to

Y The third cycle; on which the findings in this

report are based, was designed as in the preceding

children’s program to collect data on the health

status of the youth population with particular

emphasis on factors and conditions related to

their growth and development. For this a probability sample of the noninstitutionalized youths

12-17 years in the United States was selected and

examined. The questionnaires and examination

content and procedures were similar to those in

the children’s program, so as to obtain comparable information for the entire continuum of

childhood through adolescence, but were supplemented, as necessary, to obtain data specifically

related to adolescent health. Included were a

physical examination given by a pediatrician

assisted by a nurse, tests administered by a

psychologist, and a variety of tests and measurements by laboratory X-ray technicians. The

survey plan, sarnpIe design, examination content,

and operation of this survey program have been

described k-ta previous report.6

Policies for the testing of hearing and the

related examination of the ears, nose, and throat

were provided through the Subcommittee on

Hearing in Children of the Committee on Conservation of Hearing of the American Academy

of Ophthalmology and Otolaryngology, of which

Dr. Raymond E. Jordan was Chairman. Members

of the subcommittee also made onsite visits to

review the ongoing hearing examination. Facilities for the testing of hearing, training of technicians in testing and in instrument calibration,

and conduct of acoustical surveys were made

available through this group. Dr. Eldon L. Eagles,

Executive Director of the Subcommittee, served

as principal consultant in the hearing aspects of

the survey. Specific guidance on audiometric

testing and the training of the technicians in this

testing were given by Dr. Leo Doerfler of the

University of Pittsburgh. Instrument calibration,

background noise level surveys, and specific

guidance on environmental control aspects of

hearing testing were provided by Mr. Kenneth

Stewart through his acoustics laboratory at the

University of Pittsburgh. Special training in

performing the ear examination was also given

the survey staff pediatricians.

Field collection operations for the youths’

cycle started in hfarch 1966 and were completed

in March 1970. Of the 7,514 youths selected in

the national probability sample, 6,768 or 90 percent were examined. This national sample is

representative, and the examined group is closely

representative of the 22.7 million civilian noninstitutionalized youths 12-17 years in the United

States with respect to age, sex, race, region,

population size of place of residence, and rate of

change in size of place of residence from 1950

to 1960.

.4s in the preceding program among children,

examinations in the youths’ cycle were done

consecutively in 40 different locations throughout the United States. Each youth during his single visit was given a standardized examination by

the examining team in the mobile units specially

designed for use in the survey. The only exceptio-n was that the girls whose urine specimens were

found positive for bacteriutia were brought back

for repeat urine tests. Prior to the examination,

demograpliic and socioeconomic data on household members as well as medical history, behavioral, and related data on the youth to be

examined were obtained from his parents. In

addition, a Health Habits and History form was

completed by the youth before he arrived for

the examination and a Health Behavior form

was completed by him while in the examination

cent er. Ancillary data were requested from the

school attended by the youth including his grade

pIacement, teacher’s ratings of his behavior and

adjustment, and health problems known to his

teacher. A birth certificate was obtained for

each youth to verify his age and provide information related to his condition at birth.

Statistical notes on the survey design, reliability

of the data, and sampling and measurement error

are shown in append;x L Definitions of the demographic and socioeconomic terms are in appendix II.

2
HEARING MEASUREMENT AND RELATED

ENT EXAMINATION

Hcaringt hresholdlevels forthright andleft

car of each youth were determined individually

at ciSllt frequencies–250, 500, 1000, 2000,

3000, 4000, 6000, and 8000 Hertz (Hz-cycles

pcr second). Testing was done in an acoustically

treated room using air-conduction earphones with

standard pure-tone audiometers and methods

ickmtical to those in the preceding survey among

children. The related examination of the youth’s

cars, nose, and throat (ENT) given by the survey

stuff pediatrician included a general inspection

01 the external ears, routine otoscopic examination of the cxtcrna.1 auditory canals and tympanic

membranes, pneumatic otoscopy, and inspection

of the anterior nares, tonsils, and oral pharynx

identical (with a few minor deletions) to that for

children in the preceding survey.7

Testing was done by technicians specially

trained in the usc of a modified Hughson-Westlake

method in which the tone was first. introduced

at a 60-decibel (dB) intensity, decreased by 10-dB

steps until no response was obtained, then incrcasc-d 5 dB and dropped 10 dB until the lowest

intensity was reached (threshold) at which responses were obtained in 2 out of 3 or 3 out of 5

ascending trials. For the testing, the youth was

seated with his back to the window in the

acoustically treated test room in which the door

bad bum closed. The youth was seated opposite,

but not directly facing the tester, so the examinee

could not see when the signal was presented. The

technician made certain that the youth’s ears

were not obstructed with cotton, that eyeglasses,

hearing aids, earrings, and chewing gum were removed, and that hair was pulled back off the ears.

The technician then placed the earphone opening

over the ear canal making sure that the earphone

made a good seal against the youth’s ear. The

rcd earphone was placed on the right ear, the

bway on the left.

Hearing threshold or level, as used in this report, is the lowest intensity of a pure tone produced in the audiometer earphone that the youth

reports as just audible to his ear under test, in at

least one-half of the specified number of trials.

Standard audiometers for 82 percent of the tests

among youths were calibrated and maintained in

calibration in accordance with the 1951 American

Standard Association (ASA) specifications in

which the zero sound intensity level on the dial

of these instruments corresponds to the threshold of hearing for “normal” subjects with no

history of orological disease or difficulty hearing,

as determined in the 1935-36 National Health

Survey. The “audiometric zero (ASA-195 l)” or

zero point on the audiometer was expressed in

terms of the sound pressure levels in decibels

produced by the earphones in a National Bureau

of Standards (NBS) 9-A coupler when the voltages corresponding to this threshold of hearing

are applied. This audiometric zero point corresponds to a different sound pressure level for

each test frequency. During the latter part of

the survey, as the older audiometers became

more difficult to recalibrate to ASA standards,

they were replaced with newer standard audiometers calibrated and maintained in calibration in

accordance with the 1969 American National

Standards Institute (ANSI) specifications which

incorporated the standards set in 1964 by the

International Organization for Standardization

(1S0).9 ,10 The audiometric zero points at each

frequency in theASA-1951 Standard were revised

for the 1S0:1964 and ANSI-1 969 Standards on

the basis of more recent audiometric test data on

human subjects from a large number of acoustics

laboratories in various countries that were obtained with improved equipment not available at

the time the 1935-1936 National Health Survey

normative data were obtained.

Measurement of hearing level could be made

in 5-decibel steps from 100 decibels above to

10 decibels below the audiometric zero point on

the ASA-195 1 audiometers and from 80 decibels

above to 10 decibels below the audiometric zero

point on the ANSI-1969 equipment. Since the

hearing of youths is substantially more sensitive

than that of the adults tested in the Health

Examination Survey of 1960-62, the audiometers

3
were modified by the insertion of a 30-decibeI

attenuator so that testing could be done as low as

40 decibels below audiometric zero in a stable

part of the range of the instrument as was done

in the preceding survey among children. This

made a corresponding reduction in the upper

limit of intensity availabIe for testing (to 60 dB

on the ASA-1951 instruments and 40 dB on the

ANSI-1 969 units). Later the value of the attenuator was subtracted to obtain the actual hearing

level of the examinee in decibels. The decibel

values re audiometric zero, as used here, are defined as 20 times the logarithm to the base 10 of

the ratio of the sound pressure at the examinee’s

threshold of audibility (his zero sensation level)

to the reference sound pressure established for

the audiometer (audiometric zero) used. Both

sound pressures in this ratio are usually expressed

in decibels re 0.0002 dynes per square centimeter.

For analytic purposes the two sets of

measurements–the 82 percent from ASA- 1951

instruments and the 18 percent from ANSI-1969

(1S0-1964) instruments-were later all converted

to both units using the appropriate values shown

in appendix IV for each examinee. Some of the

basic hearing level findings for youths in this

report are shown both in the ASA-1951 and

ANSI-1 969 units to provide continuity with published findings for U.S. adults from the 1960-62

survey and for U.S. children from the 1963-65

survey, which were obtained and published only

in terms of the ASA-1951 units.

Before the earphones were placed, the youth

was instructed not to touch them once they were

in place. He was also told that the sound coming

from them would be like whistles or horns which

would be heard in one ear at a time and which

would get progressively fainter. The youth was

asked to show when the sound was heard and in

which ear by raising his right or left index finger.

He was further told to raise his index fiiger even

though the sound was very faint and to keep it

raised until the sound was no longer heard.

Prior to the

for at Ieast 10

was done in a

4

test the instrument power was on

minutes. The sequence of testing

randomized fashion starting with

4000 Hertz, then proceeding to 1000,6000,500,

2000, 250, 4000, 8000, and 3000. Testing of

the ears was alternated starting with the right ear

for youths with even numbered records and witil

the left ear for youths with odd case numbers

(appendix HI).

After the testing the technician indicated on

the record what conditions, if any, affected the

test results, such as a cold, ear discharge, defective equipment, earache, or other. If the technician indicated that because of the condition he

felt the hearing test results were unreliable, these

results were not used. The extent of missing data

either because the test was not given or the results

unreliable and the methods used in estimation of

these missing values are shown in appendix 1.

The technicians were trained to avoid rhythmic

presentation of signals to the youth, to skip t{)

another threshold temporarily to avoid a long,

drawn out search for a particular threshold, to

avoid visual or auditory clues when presenting

the tone, and to avoid distracting activity.

After each test session a disinfectant was

applied to the headband and earphones.

Acoustical Environment

Hearing was tested in an acoustically treated

room within a specially constructed trailer in the

mobile examining center. Inside dimensions of

tlie room measured 84 by 156 by 96 inches.

Walls, door, and ceiling were constructed of 4-

inch thick acoustical panels of heavy steel. The

room had incandescent lighting and continuous

but quiet ventilation.

Performance of the room in attenuating external noise was checked periodically throughout

the cycle by acoustical surveys conducted under

normal test conditions. Sound pressure levels

were measured both inside and outside the test

area with and without the air-conditioning equipment and under other conditions of excess noise,

When compared with the American Standards

Association’s maximum allowable sound pressure Ievels for no masking above audiometric

zero (ASA- 1951 ),1 1 the findings (shown in table
Tdla A. Acoustical sutvayl of the noise levals2 in the test room used for audiometry in the Health Examination Survey, 1866-70

Frequency bend (Hertz)

20-75 . . . . . . . . . . . . . . . . . . . . . . . . . . .

75-150 . . . . . . . . . . . . . . . . . . . . . . . . . . .

150-300 . . . . . . . . . . . . . . . . . . . . . . . . . . .

300-600. . . . . . . . . . . . . . . . . . . . . . . . . . .

600-1200 . . . . . . . . . . . . . . . . . . . . . . . . . .

600-1200 . . . . . . . . . . . . . . . . . . . . . . . . . .

1200-2400 . . . . . . . . . . . . . . . . . . . . . . . . . .

1200-2400 . . . . . . . . . . . . . . . . . . . . . . . . . .

24004800 . . . . . . . . . . . . . . . . . . . . . . . . . .

24004800 . . . . . . . . . . . . . . . . . . . . . . . . . .

4BOO-10000 . . . . . . . . . . . . . . . . . . . . . . . . .

4800-10000 . . . . . . . . . . . . . . . . . . . . . . . . .

IJUIY 22, l~66,at Portland, Maine.

2S~und pra~~”res[ndwibels re0.0002 dyne percm2.

3Test frequencies used in this study.

Audiometric

test

frequency

(Hertz)

50

125

3250

3500

750

% 000

1500

32000

33000

34000

%000

38000

A) indicate that under normal conditions with

;lir-c[>l~[litiol~ing equipment on, the room would

llwe provided sufficient attenuation ofarnbient

Ilt}ise Ii)r testing to at least 20 decibels below

;uldit}nletric zero (ASA-1951) at all test frequencies. The lowest hearing level for which there

W(lllld bc no making ranged from ~~ de~be]s

Iwl{)w ;mdiometric zero (ASA-1951) at 250

Ilcrw to 27-35 decibels below at 500-2000

Ilm-tx and 40 decibels or more below from

3000-8000 IHertz. Hence for all practical purp{ms only at the 250 Hertz frequency could

masking clue to ambient noise have produced an

clcvtitm[ rather than a true hearing level for the

fcw >uut hs whose hearing Ievels were unusually

1()W (less than 24 decibek below audiometric

zero, ASA-1 951).

During the survey it \vas not always possible

to select locations for the examining center that

prcscntcd an icleal acoustical environment for

hearing testing at all times and still meet other

conditions necessary for the rest of the survey

exam in at ion. Nevertheless, analysis of the

fimiirigs fnr the frequencies below 2000 Hertz

gives no real evidence of any noticeable degree

Maximum allowable

sound pressure

for no masking

above audiometric

zero from 1951

American Standard

(dB)

40

40

40

40

40

40

42

47

52

57

62

67

Instrument

noise

(dB)

14

12

12

11

11

11

12

12

Sound pressure

level (dB)

inside test room

All air

conditioning

off

38-42

26

12

10-11

10

10

10

12

All air

conditioning

on

,46-48

3840

16

12-13

12

11-12

11-12

12

of masking f-rem external noise, indicating that

the acoustical environment was adequate for

testing to these low levels.

Audiometer Calibration and Other Aspects of

Quality Control

Theaudiometers used in this survey to measure

hearing acuity were primarily Maico instruments+tandard electroacoustical generators with

air-conduction earphones (receivers) of type

TDH-39 with MX-41/AR cushions, providing

pure tones of selected frequencies and intensities which cover the major portion of the

auditory range, and with a manual device for

interrupting the tone.

The audiometers were modified and calibrated

at the Acoustics Laboratory of the University of

Pittsburgh to furnish reading in terms of hearing

levels in decibels on the NBS 9-A calibrating

coupler relative to the audiometric zero used in

the particular instrument-ASA-1951 or ANSI1969–at frequencies of 125, 250, 500, 750,

1000, 1500, 2000, 3000, 4000,6000, and 8000

Hertz. The audiometric zero (American Stand5
ard, 1951) for air-conduction testing is based on

findings from the clinical followup to the 1935-36

National Health Survey for that subgroup of

persons considered to have “normal” hearing.

This subgroup consisted of 1,242 persons, of all

ages and both sexes, who gave a history of normal

hearing for speech and whose hearing levels

(determined by air-conduction tests) for both

ears did not exceed a total variation of 15 or 20

decibels on the eight tones from 64 to 8192

Hertz.lz,ls

When voltages corresponding to audiometric

zero are applied, the sound pressure levels produced by the audiometric earphones commercially available at the time of these surveys

differed for each type and configuration of earphone. An indication of the extent of variability

among three of the TDH-39 earphones used at

some time during the 1960-70 period in the

Health Examination Surveys was obtained in a

loudness balance study on human subjects made

by Mr. Stewart and Dr. Ernest Burgi at the University of Pittsburgh Acoustics Laboratory for

the Health Examination Survey .14 The ASA1951 reference zero levels used in laboratory

calibration of the TDH-39 earphones of the

audiometers in the Health Examination Survey,

together with the corresponding present international reference zero levels for pure-tone audiometers adopted by the American National

Standards Institute (ANSI) in 1969 are shown in

appendix IV. Conversion to the ANSI-1969

levels were made assuming that the magnitude of

the difference in reference zero points for the

WE-705A earphones and TDH-39 earphones

would be the same in terms of the ANSI-1969

standard as had existed in the ASA-1951 standard.

During the survey among youths, each audiometer was returned to the Acoustics Laboratory

at the University of Pittsburgh for recalibration

after each of the 40 stands (locations) of the

examinations and also on the few occasions when

monitoring and calibration indicated that the

instrument was not functioning adequately.

Laboratory calibration procedures routinely included tests to determine whether the instruments were within the following American

Standards Association specifications:8

1. Frequencies generated by the audiometer

within t5 percent of the corresponding

frequency reading on the instrument.

2. The sound pressure produced by the earphones at each hearing level intensity

readings at each frequency not differing

from the normal values by more than 4

decibek at frequencies of 2000 Hertz or

less and by not more than 5 decibels at frequencies above 2000 Hertz.

3. The 5-decibeI intervals between successive

hearing level readings being not less than

3.5 decibels or more than 6.5 decibels.

4. The time required for the test tone to rise

to a value within *1 decibel of the required

sound pressure being not less than 0.1

second and not more than 0.5 seconds.

5. The sound pressure of the fundamental

signal being at least 25 decibels above the

sound pressure of any harmonic.

A typical laboratory calibration report irum

the University of Pittsburgh for one of the audiometers used in the survey among youths is

shown in table B.

In the field, audiometers were checked by tile

technician twice each day–in the morning after

the 10-minute warmup period, before testing

was started, and again after testing was completed for the day. In addition, a weekly field

sound pressure calibration at set intensity levels

was performed using Briiel and Kjaer Precision

Sound Level Meters and Artificial Ear Couplers.

Reports of the field calibration were sent routinely to the acoustics laboratory for review.

The field testing equipment was calibrated periodically by the acoustics laboratory.

As previously stated, each ear was retested

at 4000 Hertz to provide a measure of the reliability of the test results. On the average at the

various examination locations, the differences

ranged from 1 to 4 decibels or less than tile

interval between test intensities, the mag-nitudc

that might be expected in test-retest of normal

subjects. 15

6
Table B. Typical audiometer calibration results for audiometer No. 3536

Instrument frequency

Actual

(Hertz)

fraquency

(Hertz)l

250 . . . . . . . . . . . . . . . . .

500 . . . . . . . . . . . . . . . . .

1000 . . . . . . . . . . . . . . . . .

2000 . . . . . . . . . . . . . . . . .

3000 . . . . . . . . . . . . . . . . .

4000 . . . . . . . . . . . . . . . . .

6000 . . . . . . . . . . . . . . . . .

8000 . . . . . . . . . . . . . . . . .

257

506

1883

2999

4026

6011

7963

Actual attenuation of 30 dB pad = 29.2 dB

Line voltage variation: 105-125 = 0.5 dB

(ASA tolerance is 2 dB)

Intensity Second harmonic

error (dB)2 below

Red

phone

-0.5

-001

-1.7

-7.3

+0.3

+0.4

+2.9

+2.9

fundamental

1-1- frequence of

Gray

(dB)3

phone

Red Gray

phone phone

-1.5

-0.3

-2.1

-1.7

+0.5

-0.3

-0.4

+1.0 L

35+ 35+’

35+ 35+

35+ 35+

27.0+ 35+

35-F 35i35+ 35+

35+ 35+

35+ 35+

Attrjnuator4

Expected

range

(dB)

95-100

90-95

85-90

80-85

75-80

70-75

65-70

60-65

55-60

50-55

45-50

40-45

35-40

30-35

Overshoot and undershoot within ASA tolerance limits of t 1 dB

Onset time within ASA tolerance limits of .1 to .5 sec.

Decay time within ASA tolerance limits from 20 dB or more within .5 sec.

IASA fr~uency toieranca *5 parcent.

I 25-30

20-25

15-20

10-15

5-1o

0-5

- 5-o

-1o--5

<ASA Intansity toleranca at 250-2000 Hz is *4 dB, at 3000+ *5 dB. Obtained at hearing level dial readings of 60 dB.

~ASAsecond harmonic tolerance is25 dESat500, ?“OO0,2000,and 4000 Hz.

4ASA tolerance t 1.5 dB.

The randomized order of presentation of the

frcqucncics provided a further safeguard against

errors in testing,

FINDINGS

h~orc than half of the youths 12-17 years of

age in the noninstitutional population of the

United States have, at least for the better ear,

hearing thresholds lower (better) than the “normal” or audiometric zero values in the 1951

American Standard (ASA-1951 ) across all test

frequencies except 6000 Hertz, as estimated

from the Hcaith Examination Survev of 1966-70.

At all frequencies except 3000-6000 Hertz, at

least 75 percent of youths have hearing levels

Actual

interval

(dB)

4.7

4.9

5.0

5.0

5.0

5.1

5.2

5.0

5.2

5.0

5.1

4.9

5.1

4.9

5.1

4.8

4.9

5.0

4.9

4.9

4.8

5.0

lower than these ASA-195 1 audiometric zero

values (fiawre 1). Thus it is apparent that the

“normal” threshold values obtained from the

1935-36 National Health Survey followup study

on otologically normal persons were substantially higher (poorer) than the thresholds for

more than half of the U.S. youths in the present

study across all octave frequencies—250, 500,

1000, 2000, 4000, and 8000 Hertz.

In contrast, when hearing levels of these youths

are examined in relation to the 1969 American

Standard audiometric zeros (ANSI-1969) substantially less than one-half have thresholds below

these newer “normal” values-the proportion

ranging from 25 percent or less at frequencies of

250-500 and 3000-8000 Hertz to 40 and 45 per7
30

r

Percentile

+20

-------

/

,,...

---.-.-----------,,,,,.. ..

/’

‘.. ;’ ‘..

;

“----- ----- J

-—. — .

\

/

;-

‘1./:

.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

...

...

..

---- <

1’ --

-. ,!

‘. ,,

.. /

x ,1

. . . ,,

I I I I I 7 I

250 5(Q 1000 2000 4W0 Emoo

3(xXI 6000

HERTZ

5th

25th

E&h

75th

95th

Figure 2. Selected lzercentiles from the distribution of hearing

Figure 1. Selected percentiles from the distribution of hearing

threshold levels (re ASA-I 951) for the better ear of youths

12-17 years, at each tast frequency: United States, 1966-70.

cent at 1000 and 2000 Hertz (figure 2). Hence

ordy at 1000 and 2000 Hertz do roughly half of

the U.S. youth population approach the “normal”

threshoId values in the 1969 American Standard.

A subsequent report on the ear-nose-throat examination findings will determine how closely the

otologically normal youths in this study approach

these ng_wer “normal” val~es.

Hearing sensitivity of youths 12-17 years when

measured in decibel values based on the 1951

American Standard, similar to the findings for

children 6-11 years in the preceding 1963-65

national survey,T generally decreases with increase in tonal frequency up to 6000 Hertz—

slowly from 250-2000, then rapidly from 2000-

6000 Hertz.. The slight depression in median

and other percentile values at 2000 Hertz noted

in the national survey among children was not

evident for the youth population. Hearing levels

(in decibels re ASA-1951) for young U.S. adults

18-24 years of age as determined from the 1960-

62 Health Examination Survey also show a similar pattern of increase in thresholds (progressively

poorer or less sensitive hearing in relation to the

ASA-1951 norms) from 2000-6000 Hertz.lb

-20r

1-

Pmmntik

s ,, . . .

g -,0 ,,,, ..

,,,.

‘.. ,,.’

~

,. 5th

,,. ‘.. ,,

~

,,, .

,, :“

1+: -:

,,,, -...

~

v +3+3 ,~” ----

,..

:

,..

..

-.

.. ,,. 951h

..

... ,,

. ,,

+30 I I I I 1 I { I

252 EOo 1000 2UO0 4000 moo

33C42 6Ct0

HERTZ

‘threshold levels (re ANSI-1969) for the better ear of youth;

12-17 years, at each test frequency: United Stetes, 1966-70.

When measured in decibel units based on the

1969 American Standard, hearing sensitivity of

youths increased with increase in frequency from

250 to 1000 Hertz, but then median and other

percentile values showed a pattern of decrease

from 2000-6000 Hertz and an increase from

6000-8000 Hertz similar to that when measurements were in decibel units based on the 1951

American Standard audiometric zeros. (It is

readily apparent from appendix IV that the

actual intensity of sound for “normal” thresholds of hearing from either standard actually

decreases from 250-1000 Hertz, then roughly

levels off. The patterns of deviation in hearing

thresholds described above from either standard

in the present and preceding Health Examination

surveys reflect the variations in agreement with

the standard or “normal” values across the test

frequencies. Obviously agreement is closest with

the ANSI-1969 Standard at 1000 and 2000 Hertz

for the U.S. child, youth, and young adult

populations.)

Mean hearing levels

less sensitive at the

3000 to 6000 Hertz

of youths also tend to be

higher frequencies from

than at the lower tones

8
-20

r

ASA,1951

~

III -1 Q . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

N

g

..,+

...

.,’”

~

... /

%..

g

,:

%.

0

....7..... —

~ . . . . . . . . . . . . . . .

,..’

.. .

----

.l ,,,,

:

,,,, ANSI, 1969 ‘----

,,,.

II ,.,0 ---- ,,’

---- ,,f

:

+10 --,,

Ma

m~

250 rloo I000 2000 4000 8000

3000 6000

HERTZ

Figure 3. Mean hearing levels of youths 12-17 years at each test Figure 4. Percent of youths 12-17 years with difference in

hearina levels betwaen both ears of 5 decibels or less

Unite~ States, 196S-70.

children in 1963-65 and U.S. adults in 1960-62,

though in both studies the agreement diminished

with increase in frequency. Among U.S. children

the percent with no more than a 5-decibel difference between the ears decreased from 88

percent at 250-500 Hertz to lows of 67 and 69

percent at 6000 and 8000 Hertz; while among

adults the proportion decreased steadily from

80 percent at 1000 Hertz to 50 percent at 6000

Hertz.

frequency in terms of decibels re audiometric zero–ASA

1951 and ANSI 1969: United States, 1966-70.

from 250-2000 Hertz in terms of the 1951

American Standard, but only higher than at

1000 and 2000 Hertz in relation to the 1969

American Standard values for audiometric zero

(“normal”). Mean thresholds (in decibels re

ASA-195 1) were below these audiometric zero

values at all frequencies except’ 6000 Hertz,

ranging from a low of -10.0 decibels at 250

Hertz to -1.1 decibels at 4000 Hertz and to

+2.0 decibels at 6000 Hertz (table 1). In contrast, when decibel values were based on the

ANSI-1 969 audiometric zeros, the mean hearing

thresholds are consistently less sensitive than

the levels considered normal, varying between

a low of +1.1 decibels at 2000 Hertz and the

maximum of +1 1.2 decibels at 6000 Hertz (figure 3 and table 2).

Hearing thresholds for the right and left ear

of a particular individual tended to be dissimilar

for the majority of U.S. youths with the extent

of right-left ear agreement diminishing with the

increase in frequency. The best agreement was

at 500 Hertz where test levels for the -two ears

differed by no more than 5 decibels for about

46 percent of the youths. Poorest agreement

was at 6000 and 8000 Hertz where only 26 percent of youths had similar monaural thresholds

(figure 4). The extent of right-left ear agreement

among U.S. youths in the present study is substantially lower than that found among U.S.

1 i I I I I I I I I

40 20 0 20 40

PERCENT OF EXAMINEES

Figure 5. Percent of youths 12-17 years with hearing levels in

the two ears differing by more than 5 decibels: United

Stetes, 196&70.

9
HERTZ

250

I

u

0

HERTZ

~r I ‘m

343

20

10

0 I I I

-10 0 +10 +20 +30

HERTZ

40

500

30

‘m

10

0 I I I I

-lo 0 +10 +Zo +30

HERTZ

40

mm

N

30

10

0 I I I I

-lo 0 +10 +m +30

HERTZ HERTz

1-

-10 0 +10 +20 +30

HERTZ

-10 0 +1 o +20 +30

HERTz

. .

DECIBELS RE AUDIOMETRIC ZERO (ANSI-19W DECIBEIS REAUDIOMETRIC ZERO (ANSI-19W

Figure 6. Percent distribution of youths 12-17 years, by hearing levels for the better ear at each test frequency: United States, 1966-70.

10
WIKVI thL’ two ears of an individual youth did

di lTLr in hc’m-ing sensitivity (by more than 5 dB),

Jt ;LI1iwqucncics the left ear was substantially

n~[lrc lilwly than the right to be the less sensitive

(Ii:m-c 5). These findings are consistent with

thLS [indinxs umong U.S. children in 1963-65 and

LJ.S. adults in 1960-62. In all three surveys any

pmcticc effect for one ear or the other was minimixc’d l’~lrthe groups by alternating the sequence

Ijr first CM tcstml from one examinee to the next

Jnd from onc frequency to the next,

Among U.S. youths the distribution of hearing

lLVLilsis sli~htly skewed to the right for all frequcneics ( fi~urc 6 and tables 3-8), similar to the

c:ir[icr findings among U.S. children and young

;Idlllts,

Age and Sex

At 250-1000 Hertz there is little difference

between the hearing threshold levels of boys and

girls (figures 7 and 8 and tables 1-19). However,

at the higher frequencies, 2000-8000 Hertz, meal?

and median leveIs for boys consistently exceed

(poorer) those for girls by differences large

enough to be statistically significant (at the 5-

percent probability level).

For both sexes, the hearing sensitivity varied

by less than 2 decibels over the 12-17 year age

range at each frequency (except at 6000 Hertz

where the variation among boys exceeded 2.5

dB), with no consistent trend in increasing or

decreasing hearing sensitivity with increasing age.

HERTZ

250 —

— h“,

. . . ..<<-..rk -lo

0

+10

~ +20

12 13 14 15 16 17

500

HERTZ

100a 2CO0

-lo

F

-lo

F

o

d---=--“””””

.. 0 . .. . .

. .. . . . . .. . .. . . . . . . . .. .. .. . .. . .

+10 +1o

~

12 13 14 15 16 . 17

.20LJ_u._u 12 13 14 15 16 17.20L_u_u 12 13 14 15 16 17

AGE IN YEARS

3GQ0

r

40Q0

%m r

; -10

,.

-11=1 -

-lo --1o

:1

:

u

N

u

o

E

o 0

.

z

. . .. . . . . .. .. .. . . . .. . ..

. . . .. . . .. . . . .

Q

0 .. . . . . . . . . .. . . ...””””””’”””” ‘. s..”””

2

Iullll

u

+10 +10

AGEIN YEARS

6000 am

r

1-. . .

. ,+1 o

LIL_L_u_u l.._Luu +20 ~ +20 I I I I I I I

12 13 14 15 16 17 12 13 14 15 16 17 12 13 141 15 16’17 12 13 14 15 16 17 -

AGEIN YEARS AGEIN YEARS

—

Figure 7.Median hearing levels for the better ear of youths, by age and sex at each test frequency: United States, 1966-70.

11
250 Hertz 51X2Him. 1000 H,rl, Zm Hertz

— Boys

. . . . . G]rls

z 250 Fm 1030 20W 40@l moo

WFRT7

Figure 8. Median and quartiles (50th, 25th, and 75th percentiles)

from the distribution of hearing threshold levels for the

better ear of youths 12-17 years at selected frequencies, by

sex: United States, 196&70.

This fairly stable age pattern for youths was in

sharp contrast to the findings among U.S. children 6-11 years in the 1963-65 national study,

in which there was a consistent pattern of increasing hearing sensitivity with age at the lower

tones under 3000 Hertz. This would tend to

reinforce the indication in the earlier study that

at least part of this trend among children was

probably due to the shorter attention span and

the less good fit of the earphones among the

younger children.

No breakdown by age was published for the

young U.S. adults in the 1960-62 study. However, median thresholds for women 18-24 years

were consistently lower (better) than those for

young men of that age at all six test frequencies,

generally consistent with the findings among

U.S. children and youths.

Race

White youths age 12-17 years had better hearing on the average than Negro youths in the

United States in the middle frequencies 1000-

4000 Hertz, with mean differences large enough

to be statistically significant at 1000-4000 Hertz

(figure 9 and tables 1 and 2). At the higher

tones, 6000-8000 Hertz, and to a lesser degree

the lowest (250 Hertz), Negro youths had more

sensitive hearing than white youths, but only the

mean difference at 6000 Hertz was large enough

, ;$

Xx.3 Hrrl’ a

4CC0 Hertz dYXl Hertz WOO Iler!,

RACE

Figure 9. Mean hearing levels of white and Negro youths 12-17

years at each test frequency: United States, 196s3 70.

to be statistically significant. While this piilt(-rn

generally persisted throughout the agc r:i]I~:c,

mean differences were not large enough to b~’

statistically significant throughout. Mean Icwcls

for the other races are shown as a group in

tables 1 and 2, but the sample used in this study

was not large enough to provide reliable national

estimates for this small heterogeneous ,gToLIp in

the population.

White girls consistently had more sensitive

hearing than their Negro counterparts over the

entire range of frequencies (except at 6000

Hertz) with mean differences large enough to

be statistically significant at 1000-4000 Hertz.

Among boys, mean thresholds for white youths

in the middle frequencies, 1000-3000 Hertz,

were lower (better hearing) than for the Negro,

while at the extremes of the tonal range the

reverse was found. Only at 250 and 6000-8000

Hertz (Negro more sensitive) and at 3000 Hertz

(Negro less sensitive) were the mean differences

large enough to be statistically significant.

Variability in hearing threshold levels among

the youth population is greatest at 8000 Hertz,

somewhat greater at the mid-octave frequencies

of 3000 and 6000 Hertz, and least at 1000 Hertz

for both white and Negro youths, as measured

by the semi-interquartile range (tables C, 20, and

21).

The racial differences in hearing levels among

youths are generally similar to those found

among U.S. children in the 1963-65 survey and

young U.S. adults in the 1960-62 survey.

12
Table C. Maan, median, and semi. interquartile range in the distribution of hearing thresholds of white and Negro youths 12-17 years at

Frequency

250 Hertz . . . . . . . . . . . . .

500 Hertz . . . . . . . . . . . . . .

1000 Hertz . . . . ...6.. . . . .

20C10Hertz, . . . . . . . . . . . . .

3000 Hertz . . . . . . . . . . . . . .

4000 Hertz . . . . . . . . . . . . . .

600(2 Hertz . . . . . . . . . . . . . .

8000 Hertz . . . . . . . . . . . . . .

each test frequency: Unitad Statas,1966-70

White Negro

Mean Median l/2(P75 - P25) Mean Median l/2(p75 - P25)

I

9.2 9.3

5.9 5.5

1.4 0.9

1.0 0.5

5.0 4.0

7.8 7.5

11.4. 10.3

668 6.1

Decibels re audiometric zero (ANSI-1969)

4.0

5.4

3.6

4.0

5.6

5.5

5.6

6.4

8.8

5.8

2.3

2.2

7.0

9.0

9.7

6.1

8.6

4.8

1.5

1.6

6.9

8.9

9.2

5.0

5.0

5.3

4.1

4.8

5.6

4.8

5.4

6.2

?JoTE: Semi-interquartile range l/fi(F~~-p~5) includes 12.5 percent of thedistribution above and 12.5 percent below themedlan

(1’50).

250Hem

,,, -

S,jj N.rtl,t,.,,r M,drm:, s..,!, Lve,t

;;

ma f’ r

o L-—lP777am3_EzwE “. *: ~,,

N.,rth,c,,t Mid,.,, T South West

15

L

WOO Hem

ICI

Nmtlwast Madwcst Satith west

REGION

15 I

SCGHem

10

5

0

?Jonh.ast ?S$id,,esl Saurh VJesl

1s

10

F

201N Hertz

5

0 — — ~~

Norlhmss Mdwen South west

Mr 4CO0Hertz

10

5

0

No,theasl Mtd.est Samh West

15 r

SJICW Hertz

.

~--,w..

5

&::”’; ..::< ..i.

~,~; .

0

Nm’sheast Midwest Soutn west

REGION

Figure 10, Mean hearing levels of youths ?2-17 yeers at each test frequency by region: United States, 1966-70.

13
Region

Youths living in the South had less sensitive

hearing, on the average, than those in other

regions of the United States except at the lowest tone, 250 Hertz, where mean levels for youths

in the Midwest and West were higher (poorer

hearing) (figure 10 and table 22). Less consistency exists at the other extreme. At 250, 4000,

and 6000 Hertz mean thresholds for youths in

the Northeast were lowest while at 500-3000

Hertz those in the Midwest had better hearing

than those living elsewhere. Mean differences

in hearing thresholds between those in the South

and Midwest were large enough to be statistically

significant at alI frequencies except 2000 Hertz.

hIean leveIs for youths in the Northeast at 4000

and 6000 Hertz ~vere also substantially Iower

than those in other parts of the country.

Boys and girk 12-17 years of age in the South.

except at 250 and 1000 Hertz Ior boys and 250

and 6000 Hertz for girls, tcndecl to IIJVCS(Jrncwhat poorer hearing levels than those in [)1Iicr

regions of the country.

As shown in tables D and 23-26, variability

in hearing thresholds among the youth ]}(llJlil:Ition, as measured by the semi-i]ltcrclli~irtilt’ r:ll~gc

is consistently at least as hi~h w- hi@cl for

those in the South as clsewhcrc rxcept .it the

tlighest tone, 8000 Hertz. Variability in hca]-ing

levels is greatest at that highest tone in eacli {)1

the four regions.

These findings of the least sensitive hcarins

among youths in the !+kmth arc more clear-(ut

but genera]Iy consistent with those [or U.S. Lhi[-

dren 6-11 years in the 1963-65 study. Howcvc.r,

,imon,g children the variability in llcari n!< lCIVIS

Table D. Mean, median, and semi. interquartile range in the distribution of hearing thresholds of youths 12-17 years at selected fre

Region and measure

Northeast

Mean . . . . . . . . . . . . . . .

Median . . . . . . . . . . . . . .

l/2(p75-&5) . . . . . . . . . .

Midwest

Mean . . . . . . . . . . . . . . .

Median . . . . . . . . . . . . . .

l/2( P75-P25). . . . . . . . . .

South

Mean, . . . . . . . . . . . . . .

Median . . . . . . . . . . . . . .

l/2(P75- P25) . . . . . . . . . .

West

Mean . . . . . . . . . . . . . . .

Median . . . . . . . . . . . . . .

l/2( P75-P25). . . . . . . . . .

quencias, by ragion: United Statas, 1966-70

Frequency

250 500 1000 2000 4000 8000

Hertz Hertz Hertz Hertz Hertz Hertz

Decibels re audiometric zero (ANSI-1969}

8.0

8.2

4.8

10.0

9.9

3.8

8.8

8.9

4.8

9.4

9,4

3.8

5.7

5.3

5.4

5.6

4.9

5.0

6.9

6.7

5.4

5.6

5.0

5.3

1.6

1.0

3.6

1.0

0.6

3.6

2.1

1.3

3.8

1,8

1.1

3.6

0.9

0.6

3.8

0.8

0.5

4.0

1.4

0.7

4.4

1,2

0.7

4.0

6.4

6.3

5.5

7.9

7.9

5.2

8.9

8.3

5.6

8.6

8.1

5.4

5,6

4.6

6.2

7.1

6.5

6.3

8.7

7.9

6.3

5.5

4.4

6, i

NOTE: Semi-interquartile range 1/2(P75 -Pz5) includes 12.5 percent of the distribution above end 12.5 Percent below the median

(P5CI).

14
was gcIwdy highest among those in the West,

r:ttl]cr than the South as noted among these

youths.

Size of Place of Residence

Youths living in urban communities not dif-

~crcntiatcd by population size have hearing thresholds that differ little, on the average, from

LI1OSCliving in rural areas of the United States

( li~m-e 11 and table 27). At the lower tones of

250-1000 Hertz, rural dwellers have slightly more

sensitive hcming than their urban counterparts

{~n the average, while urban residents have slightly

better Imtiring at 2000-8000. None of the mean

c[itfcrcmccs arc large enough to be statistically

si~nlific;tnt.

There is also no consistent pattern of hearing

levels among urban dwellers that varies with the

population size of the community. Youths in

the smallest urbanized areas of less than 250,000

(:it frequencies of 250, 2000, 3000, and 8000

I-Icrtz) and those outside urbanized areas in

places of 10,000-24,999 population (at 500,

1000, 4000, and 6000 Hertz) tended to have

somewhat higher mean thresholds (poorer hearing), while those in the largest metropolitan

arm of 3 million or more (at 250, 500, and

4000-8000 Hertz) and 1-2.9 million population

lfl l—

250 Hwtz 600 Hmtz 10W Hertz 20W Hertz

I

;

10

9 !,

<

G

ma

E urlmn Rural Urban Rural Urban Rural

~

Urban Rural

.

L

‘w

5

q 1!1 ~

3000 Hertz 4fx10 Hertz 6000 Hertz 8000 Hertz

PLACE OF RESIDENCE

Figure 11. Mean hearing levels of urban and rural youths 12-17

years at each test f requency: United States, 1966-70.

(at 1000 Hertz)

(better hearing)

(table 28).

had slightly lower mean levels

than youths living elsewhere

These findings of negligible urban-rural differences in mean hearing thresholds for U.S. youths

in the present study are generally consistent with

the findings for U.S. children 6-11 years in

1963-65.

Rate of population change.-One of the three

axes of stratification used in the sampling frame

for this national survey as well as the preceding

one among children was the extent and direction

of change in population size of place of residence

from 1950 to 1960. This was considered an

indirect measure of the economic stability of

the communities in which these youths reside.

Places with an above-average gain in population

during the decade were more likely to have a

healthy expanding economy, while those experiencing a loss were more likely to have diminishing employment opportunities and resources for

development. It might be expected that this

factor of rate of population change would in

turn be reflected to some extent in the degree of

hearing sensitivity of youths living in these types

of areas insofar as this might also reflect the

availability and adequacy of medical care.

Youths living in places showing an aboveaverage gain in population tended to have better

hearing consistently across all test frequencies

than those from communities where the increase

was slower or there was a population loss (figure

12 and table 29). While high-low mean differences were large enough to be statistically significant at 250, 500, 4000, and 8000 Hertz, there

was no other consistent relationship evident with

this economic indicator.

These findings of slightly better hearing levels

among youths living in communities with aboveaverage gains in population than elsewhere are

generally consistent with the findings among

children 6-11 years in the 1963-65 national study.

Family Income

Hearing sensitivity of youths shows a strong,

consistent relationship to the income level 01

15
15

s

15

:

~ ,0 10

z

~

0

a

5 5

:

g o 0

~!~ i~

Loss Below average Averagegain Aimw avera~ Loss Belowaverage Averagegain Aba,e averm

gain g4in WI. mtn

~ 15 15

m

~

02

z

10 10

~

0

u 5 5

:

Q.

o

g Loss Below average Averagegain Above average Loss Belowaveras Averagegain Above avera~

z

gain

0

gain gain gain

z

3

<

15 15

u

j 10 10

%

g5

n

5

0 0

Loss Below averags Averagegain Above average Loss Belowaveray Averagegain Akm avarap

gain gain gain gain

RATE OF POPULATION CHANGE RATE OF POULATION CHANGE

Figure 12. Mean hearing levels of youths 12-17 years at each test frequency, by rate of population change in place of residence from

1950 to 1960: United States, 1966-70.

their families (figure 13 and table 30). The

least sensitive mean hearing levels across all test

frequencies were consistently among youths in

families with the lowest annual income, less than

$3.000, while the most sensitive hearing levels

were found among youths in families with annual

income of $15,000 or more, except at 250 and

6000 Hertz where those in the income brack=t

$10,000-$14,999 had sl~htly lower (better)

mean thresholds. The mean differences between

thresholds for youths from the lowest income

bracket and those from the Klgher brackets of

$10,000 or $15,000 and over are consistently

statistically significant.

Though successive differences from one income bracket to the next highest were not generally large enough to be statistically significant,

the mean thresholds for youths from families

with less than $5,000 a year income were consistently higher (poorer hearing) than those in

families with annual income of $5,000 or more.

Also at frequencies of 1000,2000,3000,4000,

and 8000 Hertz mean hearing thresholds of

youths in the lowest income families were significantly higher (poorer) than those in families

with .$5,000 or more annual income.

At test frequencies of 2000 Hertz and higher,

girls were found to have more sensitive hearing

than boys across all income levels.

The variability in hearing sensitivity of youths,

16
i ‘fir 25o Hertz

1000 Hertz

~; 6

a

o t~.. .\.

Lessthan S3.MIO. $5,000- $7,000 $10,OWJ S15,0CQ

s3,0ao $4,999 .%,999 $9,999 $14,999 or more

Lessthan $3,000 s5,0m $7,0+10. $10,002. $15,000

$3,002 S.W99 S6,999 $g,g~g $14,999 orm.re

$3,003 $4,999 ‘%,999 $9,999 $14,999 ormore

ANNUAL FAMILY INCOME

15

F

500 Hertz

10

5

0

Lessthan $3,000- $5,0W $7,0m $lo,om $15,000

$3,000 *,999 S6,999 $9,999 S14,999 ormore

15

10

L_.

2000 Hem.

5

.,,,.,.,.:,,

,.,,,:,,,..

0

Lmthan 63,000. $5,00@ s7,Lm $10,SOG $15!XKI

$3,000 $4,999 $6,999 $9,999 $14,999 ormore

15

bmfzwrlm

41XSIHew

10

.

, :;.:,;,..

5

. . . . . . . . .

\

. . . . . . . . .

. . . . . . .

. . . . . . . .

;::.::::.

. . . . . . . . .

. .

0

::::..::.

.

Lessthan $3,CII0. S5,W3. $7,000 $1OACO $15JO0

S3,000 .%999 .%999 $9,999 $14,999 ormore

15

L

8000 Hertz

10

5

0

Lessthan $3,1YJ0. $5,000. $7,@3. $10,OOO $15,0W

S3,000 $4,999 $6,9~9 $9,9%7 $14,999 ormore

ANNUAL FAMILY INCOME

Figure 13. Mean hearing levels of youths 12-17 ysars at each test frequency by annual family income: United States, 1966-70.

as measured by the semi-interquartile range, generally tends to remain the same or to decrease

gradually with increasing family income levels

(table E).

The findings in this study among U.S. youths

with respect to the relationship of hearing thresholds and annual family income are similar to

those from the 1963-65 survey among U.S. children and among adults in the 1960-62 national

sLlrvcy. However, among children the variability

in hearing sensitivity as measured by the semiinterquartile range showed no consistent pattern

of relationship to family in~ome such as that

found among youths.

Education of Parent

Hearing sensitivity of youths in this country

tended to increase with the number of years of

formal education completed by their parent who

was considered head of the household [figure 14

and table 31). Mean differences between hearing

thresholds of those whose parent had the least

education (less than 5 years) and those with 4

years or more of college training were large

enough to be statistically significant for frequencies of 500 Hertz and higher. Generally, differences in hearing thresholds for youths between

successive parent education levels were not large

enough to be statistically significant.

17
Table E. Maan, median, and aami-intarquertile renge in tha distribution of haaring thresholds of youths 12.17 years at aach tast fraFamily income and

measure

Lessthan $3,000

Main . . . . . . . . . . .

Median . . . . . . . . . .

l/2(p75-p25). . . . . .

$3,00%$4,988

Mean . . . . . . . . . . .

Median . . . . . . . . . .

l/2( P75-P25). . . . . .

$5,000-$6,988

Mean . . . . . . . . . . .

Median . . . . . . . . . .

l/2(p75-p25). . . . . .

$7,000-$9,988

Mean . . . . . . . . . . .

Median . . . . . . . . . .

l/2(p75-p25). . . . . .

$10,000-$14,000

Mean . . . . . . . . . . .

Median . . . . . . . . . .

l/2(p75-p25). . . . . .

$1,5,000 or more

Mean . . . . . . . . . . .

Median . . . . . . . . . .

l/2(p75-p25). . . . . .

quency, by annuel family income: Unitad States, 1966-70

Frequency

250 500 1000 2000 3000 4000 6000 8000

Hertz Hertz Hertz Hertz Hertz Hertz Hertz Hertz

Decibels re audiometric zero (ANSI-1969)

10.0

9.8

4.2

9.8

9.8

4.2

9.0

9.1

4.0

9.1

9.1

4.1

8.7

9,0

4.0

8.8

9.1

3.8

7.0

6.6

5.6

6.9

6.8

5.4

6.0

5.8

5.3

5,8

5.4

5.4

5.1

4,2

5.2

5.0

4.6

5.3

3.1

1.9

4.6

2.6

1.9

4.4

1.6

1.1

3.6

1.6

0,9

3.5

0.8

0.5

3,6

0.2

0.3

3.4

2,6

1.6

4.8

1.9

1.3

4.6

1.0

0.6

3.8

oa

0.5

3.9

0.4

0.1

4,2

0.1

-0.1

4.0

7.3

6.9

5.7

6.6

5.9

5.6

5.2

4.1

5.5

4.9

4.0

5.6

4.4

3.5

5,4

4.1

3.4

5.4

9.9

9.2

5.1

9.2

8.8

4.8

8.0

7.9

5.4

7.6

7.3

5.5

6.8

6.5

5.6

6.4

6.6

5.4

12.2

11.0

6,5

11.8

10.7

5.6

11.1

10.2

6.0

10.9

9.8

5.2

10.4

9.8

5.4

11.0

9.9

5.7

8.4

7.1

6.7

7.8

7.0

6,5

6.6

5.8

6.4

6.6

5.7

6,4

6.0

5.7

6.2

5.2

4.7

6,4

NOTE: Semi-interquartile range l/2(P75 - P25) includes 12.5 percent of the distribution above and 12.5 parcant balow the median

(P51J).

These findings among youths with respect to

the positive relationship of parent education to

the youth’s hearing differed little from those

umong U.S. children in the 1963-65 survey and

among U.S. adults in the 1960-62 survey.

Estimated Hearing Levels for Speech

As in the previous Health Examination surveys among adults and children, speech-reception

thresholds were not measured for youths in this

survey examination. However, a frequently used

method recommended by the American Medical

Association’s Committee on Medical Rating of

Physical Impairment 17_ and the American Academy of Ophthalmology and Otolaryngologyl 8

is obtained by averaging the levels of the puretone frequencies usually considered most essential for understanding speech–500, 1000, and

2000 Hertz for the better ear. Data from the

18
25J3Hertz

10

L1

$& 5

08~To

Lessthdn 5-7 8 9.11 12 13.15 16 17

~q

IUS! 5 or more

1000 Hem

~

a

G

o —

Lm$than 5.7 8 9.11 12 13.15 16 17

El or more

15 r

3000 Hertz

10L

g h

1 mpqm~~l.q %2 ~

u ;’;?>/, .:,.,,.,.,., ,.,.:. ...

0

Es LL?SSthdn 5-7 8 911 12 13.15 16 17

@J 5 .

r,.

or more

Lessthan 5-7 8 9.11 12 13.15 16 17

5 or more

500 Hertz

5 or more

5

2000 Hertz

o

~

5 I_

Lessthan 5-7 8 9.11 12 13.15 16 17

5 m more

5 or more

YEARS OF SCHOOL COMPLETED BY PARENT

5 or more

YEARS OF SCHOOL COMPLETED BY PARENT

Figure 14. Mean hearing levels of youths 12-I 7 years at each test frequency, by education of parent: United States, 1966-70.

distributions of these estimates are shown in

tables 1, 2, 17-26, 28, 29, and 30.

hlost of the youths in this country have estimated thresholds for speech lower than audiometric zero (ASA-195 1) as shown in figure 15

and tables 17-19. For 75 percent of the youths

this threshold was at least 1.5 decibels below

(better than) audiometric zero (ASA-1951).

However, in the newer standards only about 25

percent of the youths have estimated hearing

thresholds for speech lower than audiometric

zero re ANSI-1969 and slightly more than 50

percent had median hearing levels less than 5

decibels above the 1969 American Standard for

audiometric zero.

The Committee on Conservation of Hearing

proposed a classification of hearing handicap for

audiometric survey purposes which contains approximate gradations of impairments that are

related solely to pure-tone audiometric measurements but are not related to medical diagnosis

and which deliberately disregards the numerous

other types of difficulties in understanding

speech. 19 (See table F).

The prevalence of hearing handicap for speech

among youths in this country, as estimated here,

is very low. Less than 1.5 percent or approximately 281,000 youths 12-17 years of age have

hearing levels 15 decibels or more above audiometric zero (ASA-195 1) within the critical speech

range.

Essentially all of these youths fall within the

groups who have some clifficulty only with faint

or normal speech. None had a hearing handicap

severe enough to interfere with understanding

amplified speech, indicating that the proportion
— BOW

. . . . . . . G,,l,

ASA 1951

-15

K-z

25th

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . .

10 501h

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . .. . .

.5 75th

. . . . . . . . . . . . . .

0

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

;+5~

=

12 13 14 15 16 17

0 AGE IN YEARS ~

-1?

ANS11S69

K_

Y .5 25th

E~

o

:

Yhh

. . . . . . . . . . . . . . . . . . . . . . . . . . . .

+5

75th

+10 . . . . . . .. . . . . . . . . . . . . . . . . . . .. .. . . . . . . . . . . . . .. . . .. . . . . . . . . . . . .. . .. . . . . . . . . . . .

+15 ,-4-

AGE IN YEARS

Figure 15. Median and quartiles from tha distribution of youths

12-17 years, by hearing threshold Ievals for speech (avaraga

of puretone levels at 500, 1000, and 2000 Hertz) in the

better ear: United States, 196&l 970.

of youths of this age with this degree of defect

is too small to measure reliably wi:h the size of

the sample used in this survey.

These estimates of hearing handicap in the

youth population will of course be an understatement of the magnitude of the problem since

the target population for the survey was limited

to the noninstitutionalized and would have excluded youths living in special institutions for

the hearing impaired.

At the other extreme, slightly more than 1

percent of youths 12-17 years of age had hearing

levels of 15 decibels or more below audiometric

zero (ASA-195 1) within this range of frequencies

considered most essential for speech.

As noted for the individual frequencies comprising the speech reception threshold estimates,

similar mean (speech) thresholds were found fc~r

boys and girls among these youths as among

U.S. children in the 1963-65 study and among

the young U.S. adults in the 1960-62 study.

However, the prevalence of hearing handicap

among youths in this study is slightly higher

than among U.S. children- 1.3 percent as compared with less than 1 percent or approximately

68,000 more youths than children.

Table F. Estimated percentage of the youth population, by gradation of hearing handicap: United States, 1966-7G

Average hearing level in decibels re

audiometric zero for 500, 1000, and

2000 Hertz in the better ear

ASA-1951

Lessthan15dB . . . .

15-29 dB . . . . . . . .

Z&44dB . . . . . . . .

45-59 dB . . . . . . . .

60-79 dB . . . . . . . .

800rmoredB . . . . .

ANSI-1969

Less than 26 dB

26-40 dB

41-55 dB

56-70 dB

71-90 dB

91 or more dB

Ability to understand

speech

No significant difficulty

with faint speech

Difficulty only with faint

speech

Frequent difficulty with

normal speech

Frequent difficulty with

loud speech

Understands only shouted

or amplified speech

Usually cannot understand

even amplified speech

Both

1

Boys

I

Girls

sexes

98.76

1.02

0.19

*

●

Percentage

98.57

1.19

0,22

—

*

●

98.96

0.84

0.16

●

●

20
COMPARISON WITH PREVIOUS STUDIES

The present study is the first in which findings

i.t~~ representative of the junior and senior high-

::chool-age population of the United States. In

rcccnt years there have been several large-scale

st[.ldics which obtained data on hearing thresholds for selected groups of young adults. Some

of these studies were limited to the otologically

n(]rnl~ und ~vere done specifically to determine

lwaring Icvcl norms. The earliest of these largeKak suweys was the 1935-36 National Health

.

hurvc’y . A mo~e intensive study~ O was recently

tmrnplcttd in Pittsburgh, Pennsylvania, during

tYbich hwring threshold levels were determined

for cl~ildrcm in the elementary schools, both

public ;md private. Reference is limited here

to Nudics presenting findings on young adults

in Ivhich sorne~vhat similar testing methods to

those in the present survey were used.

The National Health Survey of 1935-36 provid~d the basis for obtaining the data used in the

1951 American Standard audiometric Zero.l9 In

d clinical fcdlowup investigation some 9,000

persons of all ages residing in selected cities of

the IJnited States were examined and tested.

Hm~-in~ threshold levels were determined by airCI,ncluction testing at eight pure tones—64, 128,

256, 512, 1024, 2048, 4096, and 8192 Hertz–

~cneru tcd by standard audiometers (Western

Elcctriu 2-A, earphone type 552). Testing was

dons in booths constructed to give effective insukltion from ambient noise. The 1951 Amerimn St,mdard (for audiometric zero) was based on

hcarin: thresholds for 1,242 persons determined

to be otdogicidly normal. Because of the method

used for selecting the study group from these

urban communities, the findings cannot be assumed to bc representative of the urban population of this country at the time of the study. It

is ~munlcd here that threshold levels obtained at

256, 512, 1024, 2048, 4096, and 8192 Hertz

arc approximately the same as those at the appr[mimatc octave frequencies of 250,500, 1000,

2000, 4000, and 8000 Hertz used in the present

study.

Hearing levels for’ young adults 18-24 years

of age based on findings from the 1960-62

Health Examination Survey among a nationally

representative sample of adults have been published.16 This study, as previously indicated,

was based on examination findings for nearly

6,700 persons from a national probability sample

selected to represent the civilian noninstitutionalized population 18-79 years of age. In the survey

examination, threshold levels were determined

by air-conduction testing at six pure tones–500,

1000, 2000, 3000, 4000, and 6000 Hertz–

generated by standard audiometers with TDH-39

earphones. Testing was done in booths constructed to achieve effective insulation.

Data obtained at the 1955 Wisconsin State

Fair have been presented on 122 persons 18-24

years of age considered to be otologically normal.z 1 The subjects were drawn frdm among

persons of all ages who attended the fair, primarily from Milwaukee and the surrounding area.

Testing was done with standard audiometers by

air-conduction (TDH-39 earphones) in prefabricated test rooms at nine tones–125, 250, 500,

1000, 2000, 3000, 4000, 6000, and 8000 Hertz.

From their study in Britain in 1952 Dadson

and King published data on 99 persons 18-24

years of age considered to be otologically normal.z z These subjects who were employees of

the National Physical Laboratory were trained,

highly motivated listeners. Testing which was

done by air-conduction with standard audiometers (4026-A earphones) in a very silent, absorbent room was carried out at 14 pure tone

frequencies–80, 125, 250, 500, 1000, 1500,

2000, 3000, 4000, 6000, 8000, 10000, 12000,

and 15000 Hertz.

Eagles, et al., at the University of Pittsburgh

Graduate School of Public Health, in cooperation with the Committee on Conservation of

Hearing of the American Academy of Ophthalmology and Otokryngology, conducted a study

from 1958 to 1960 on a group of 4,0.78 children

in the public and private schools of Pittsburgh,

Pennsylvania.z O The subjects who were between

5 and 14 years of age were a representative

21
cross section of

population. In

determined by

the “Pittsburgh elementary school

this study, threshold levels were

air-conduction testing at seven

pure tones–250, 500, 1000, 2000, 4000, 6000,

and 8000 Hertz-generated by standard audiometers with WE-705A earphones in prefabricated

test rooms constructed to achieve effective attenuation of ambient noise.

Findkgs from the various studies cited in this

section have been converted to a uniform base

(for TDH-39 earphones on the NBS 9-A coupler

expressed in decibels re 0.0002 dynes per square

centimeter). This is a scale different from that

used to present data elsewhere in this report

(appendix III). Some factors which cannot be

compensated for are differences in acoustical

environment, testing technique, stability of the

instruments used, and selection and motivation

of the test subjects. These are confounded with

any rea.i differences that may exist among the

populations themselves.

Median hearing levels obtained for U.S. youths

in the present study differ substantially from

those for the otologically normal group in the

1935-36 National Health Survey whose thresholds were used in determining the 1951 American Standard reference zero (figure 16).1 3~z3

The levels for youths 12-17 years of age in the

present national study are from 10 decibels to

less than 2 decibels lower (better), depending on

the frequency, than those of the otoscopically

normal young adults in the 1935-36 National

iiealth Survey.

Findings from the present survey are in closer

agreement with those for more recent studies

cited here which present data on hearing levels

of young adults and children. The median hearing levels found in the present study differ by no

more than 2.5 decibels from the medkm levels

for young U.S. adults 18-24 years of age from

the Health Examination Survey findings in 1960-

62 and by slightly more than 4 decibels from the

mechan hearing levels for U.S. children 6-11 years

of age from the 1963-65 Health Examination

Survey findings.

22

50

40

.

10

@) ---

@,-----

,@—

\

@—-— m ---------

@---- @ ...........

(go ●

\/

1951 S!andarcl

Ameocan A.dwnetrm Zero

U.S, II 2.17 yearsl

U.S. 118.24 years)

Wwms!n State Fmr study

D,adson and Kmq Study

Pittsburgh Stud”

U.S. (6 11 yeari

1969 Standard

Arnencan Aud,ornetrhc zero

,~

250 5W low 2000 4m 8000

HERTZ

Figure 16. Median hearing threshold levels for right ear (in

deeibels re 0.0002 dynes per cm2) for youths and young

adults at selected frequencies, from selected studies.

SUMMARY

Hearing threshold levels among youths 12-17

years of age in the noninstitutiona]ized population of the United States, as determined from the

Health Examination Survey of 1966-70, have

been described and analyzed in this report. Some

findings are presented in decibel units based on

the 1951 American Standard and all are shown

in units based on the 1969 American Standard

for audiometric reference zero. Age, sex, racial,

regional, urban-rural, income, and educational

differentials in hearing levels are assessed.

For the 1966-70 Health Examination Survey,

a probability sample was selected as representative of the 22.7 million civilian noninstitutionalized youths 12-17 years of age in the United

States at midsurvey time. Of these, the 6,768

examined, 90 percent of the sample, were closely

representative of the youth population from

which they were drawn with respect to age, sex.

race, re$on, and other demographic and socioeconomic variables considered in this report.
Comparison is made throughout with the hearing

hxwls among U.S. children 6-11 years of age

from the 1963-65 Health Examination Survey

und the young U.S. adults 18-24 years of age

from the 1960-62 Health Examination Survey.

Major findings from the study among youths

include:

1. For their better ear more than half had

hearing thresholds below (better than) the

ASA- 1951 standard for audiometric zero

( 1951 American Standard) at all frequencies tested except 6000 Hertz.

2. For the better ear less than 50 percent had

hwu-ing thresholds below (better than) the

ANSI- 1969 standard for audiometric zero

(1969 American Standard) atall frequencies

tested.

3. Hearing was somewhat poorer (in relation

to the 1951 American Standard) at 3000,

4000, and 6000 Hertz than at the lower test

frequencies.

4. Hearing thresholds for the right ear as compared with the left were dissimilar (by more

than 5 decibels) for most of the youths.

The extent of agreement tended to diminish

with increasing frequency.

5. Hearing levels for girls are generally lower

than among boys, by mean differences

large enough to be statistically significant

at 2000-8000 Hertz.

6. The prevalence of hearing handicap as estimated from the pure-tone audiometric test

results in this survey is quite low. only

about 1.5 percent or an estimated 281,000

youths 12-17 years of age in this country

have some degree of hearing handicapmean thresholds of 15 decibels or higher

(re 1951 ASA audiometric zero) at frequencies of 500-2000 Hertz; however, this

does not include youths residing in special

schools for the hearing impaired or in other

institutions.

7. Hearing sensitivity of youths showed a generally consistent relationship with family

income. Youths from families with less

than $5,000 per year had higher mean

thresholds (poorer hearing) than those

from families with income of $5,000 and

over, with mean differences large enough

to be statistically significant at all octave

frequencies. A similar but less strong relationship was found between hearing levels

of youths and parent education.

000

23
1National Center for Heafth Statistics: Origin, program, and

operation of the U.S. National Health Survey. Vital and Health

Statistics. PHS Pub. No. 1000-Series 1-No. 1. Public Health

Service. Washington. U.S. Government Printing office, Aug. 1963.

2Nationaf Center for Health Statistics: Plan and initiaf program of the Health Examination Survey. Vital and Health

Statistics. PHS Pub. No. 1000-Series l-No. 4. Pubfic Heafth

Service. Washington. U.S. Government Printing Office,Jufy 1965.

3Nationaf Center for Heafth Statistics: Cycle I of the Heafth

Exarnimtion Survey, sample and response, United States, 1960-

62. Vital and Health Statist/es. PHS Pub. No. 1000-Series 11-

No. 1. Pubfic Health Service. Washington. U.S. Government

Printing Office, Apr. 1964.

4Nation~ Center for Health Statistics: Plan, operation, and

response results of a program of children’s examinations. Vital

and Health Statistics. PHS Pub. No. 1000-Series 1-No. 5. Pubfic

Heafth Service. Washington. U.S. Government Printing Csffice,

Oct. 1967.

5National Center for Health Statistics: Sample design and

estimation procedures for a National Heafth Examination of

children. Vital and Health Statistics. PHS Pub. No. 1000-

Senes 2-No. 43: Public Health Service. Washington. U.S.

Government Printing Office, Aug. 1971.

6Nationaf Center for Health Statistics: Plan and operation of a

Heafth Examination Survey of U.S. youths 12-17 years of age.

Vital and Health Statistics. PHS Pub. No. 1000-Senes l-No. 8.

Public Health Service. Washhgton. U.S. Government Printing

office, Sept. 1969.

7National Center for He&b Statistics: Hearing levels of

children by age and sex, United States. VitalarsdHealth Statists”cs.

PHS Pub. No. 1000-Series 1l-No. 102. Public Health Service.

Washington. U.S. Government Printing Office, Feb. 1970.

8Amencan Standards Association: American Standurd Specifications for Audiometers for General Diagnostic Purposes.

Pub. No. Z24.5-1951. New York, 1951. .

9Amefican Nation~ Stmduds Institute: American Stan&rd

Sfsec~ications for Audiometers. Pub. No. S3.6-1969. New York,

1969.

10Intemational Organization for Standardizatiorx 1S0 Recommendation R 389-Stan&rd Reference Zero for the Calibrah”on

of Pure Tone Audiometers. ISO/R 389-1964 (E). Switzerland,

NOV. 1964.

1l~encan Stmdads Assouation: Amen-can Standard

Cra”teriafor Background Noise in Audiometer Rooms. Pub. No.

s3.1-1960. New York, 1960.

12Nation~ Institutes of He~th: Hearing Study Series BtdletinS

1-7, The Nationaf Health Survey, 1935-36, preliminary reports.

Public Health Service. Washington, D.C., 1938.

13Corliss, E. L. R., and Snyder, W. F.: Calibration of

audiometers. J. Acoust. Sot. Amer. 22(6):837.842, Nov. 1950.

14Nationaf Center for Health Statistics: Loudness balance

study of selected audiometer earphones. Vital and Health

Statistics. PHS Pub. No. 1000 -Series 2-No. 40. Public HeaIth

Service, Washington. U.S. Government Printing Office, Dec. 1970.

15Ch~~, J. B., and Ventry, I. M.: Functional hearing h.

Ch. 3 in J. Jerger, cd., Modes-n Developments in Audiology.

New York. Academic Press, 1963, p. 91.

16NationA Center for He~th Smtistics: Hearing levels of

adults by age and sex, United States, 1960-62. Vital and Heulth

Statistics. PHS Pub. No. 1000-Series 1l-No. 11. Pubfic He.dth

Service. Washington. U.S. Government Printing Office, Oct. 1965.

17Committee on Me&~c~ Rating of Physimf Imptimlcnt:

Guide to the evacuation of permanent impairment-ear, rmsr,

throat, and related structures. J.A.M.A. 177:489-501, Aug. 19,

1961.

18Committee on Conservation of Hearing: Guidr for the

evaluation of hearing impairment. Tr. Am. Acad. Ophth. 63(2),

Mar.-Apr. 1959.

19Nationaf Institutes of Heafth: Methodological problems in

collecting data on the deaf, the survey by E. L. Eagles.

Proceedings-Conference on the Collection of Statistics of Severe

Hean”ng Impairments and Deafness in the United States. PHS

Pub. No. 1227. Public Health Service. Washington, U.S. Govcm.

ment Printing Office, 1964.

2%agles, E. L., Wishik, S. M., Doerffer, L. G., Melnick, W.,

Levine, H. S.: Hearing sensitivity and related factors in chifdren.

The Laq&goscope. June 1963.

21Glong, A.: A report of two normaf hearing studies. -&m.

Otol. Rhin. &Laryng. 67(1):93-111, Mar. 1958.

22Dadson, R. S., and King, J. H.: A determination of the

normal threshold of hearing and its relation to the standardization

of audiometers. J. Laryng. &’Otol. 66:366-378, Aug. 1952.

23Burkhard, M. D., and Corliss, E. L. R.: The response of

earphones in earsand couplers. J. Acoust. Sot. Amer. 26(5):679-

685, Sept. ”1954.

24Nationa Center for Health Statistics: Quafity controi in a

Nationaf Health Examination Survey. Vital and Health Statistics.

Series 2-No. 44. DHEW Pub. No. (HSM) 72-1023. Health Services

and Mental Health Adminiitration. Washington. U.S. Government

Printing Office. Feb. 1972.

25person~ commu~cation from ~son ~boratories and used

in Cox, J. R., and Bifger, R. C.: Suggestion relative to the standardization of loudness balance data for Telephonfcs TDH.39

e~hone. J. Acoust. SOC. Amey. 32:1081-1082, Aug. 1960.

26Da~s, H., and fin~, F. W.: ‘l’he intemation~ st~d~d

reference zero for pure-tone audiometers and its relation to the

evaluation of impairment of hearing. J. Speech Hear. Res.

7(1):7-16, Mar. 1964.

27Davis, H.: The 1S0 Zero-reference level for audiometers.

Arch. Otofusyng. 81:145-199, Feb. 1965.

28 Glorig, A.: Audlometrfc reference levels. Laryngoscope.

76:842-849, May 1966.

29Weiss1er,p.: Intemation~ st~~d reference zero for audi.

ometers. J. Acoust: Sot. Amer. 44(1):264-275, July 1968.

30 British Standards Institution: Bn”tish Standard Specifications for the Normal Threshold of Hearing for Pure Tone by

Earphone Lsktening. B.S. 2497. London. British Standards

House, Inc., 1954.

24
LIST OF DETAILED TABLES

Table

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

11.

12.

13.

14.

15.

16.

Mean hearing levels re audiometric zero (ASA-1951 ) in the better ear of youths at each test frequency

and estimates for speech, by race, age, and sex: United States, 1966.7 O...... ............ .......... ........................

Mean hearing levels re audiometric zero (ANSI-1969) in the better ear of youths at each test frequency

and estimates for speech, by race, age, and sex: United States, 1966-70 .... ..............................................

Percent distribution of youths 12-17 years by hearing levels in decibels re audiometric zero (ASA-1951 )

for the right, left, and better ear at 250, 500, 1000,2000,3000,4000, 6000, and 8000, Hertz: United

States, 1966-70... ............ .............................. .... .................. .................................... ...................................

Percent distribution of boys 12-17 years by hearing levels in decibels re audiometric zero (ASA-1951 )

for the right, left, and b~er ear at 250, 500, 1000, 2000, 3000, 4000,6000, and 8000 Hertz: United

States, 196&70 ..........................................................................................................................................

Percent distribution of girls 12-17 years by hearing levels in decibels re audiometric zero (ASA-1 951) for

the right, left, and be~=ear at 250, 500, 1000, 2000, 3000, 4000, 6000, and 6000 Hertz: United

States, 196G70 ................................... ......... .................................................................. ............................

Percent distribution of youths 12-17 years by hearing levels in decibels re audiometric zero (ANSI-1969)

for the right, left, and better ear at 250, 500, 1000, 2000, 3000, 4000,6000, and 8000 Hertz: United

States, 19~.70.0...m ........................................................................................................................j ...........

Percent distribution of boys 12-17 years by hearing levels in decikls re audiometric zero (ANSI-I 969)

for tha right, left, and b~er ear at 250, 500, 1000,2000,3000,4000, 6000, and 8000, Hertz: United

States, 196&70 ........ ...................................... ...................... ......................................................................

Percent distribution of girls 12-17 years by hearing levels in decibels re audiometric zero (ANSI-1969)

for the right, left, and ~er ear at 250, 500, 1000, 2000, 3000, 4000, 6000, and 8000 Hertz: Unitad

Statas, 1966.70 .................................................................................................................. ........................

Percent distribution of youths by hearing levels in decibels re audiometric zero (ASA-1951 and

ANSI- I 969) for the better ear at 250 Hertz, according to age and sex: United States, 1966-70 .................

Percent distribution of youths by hearing levels in decibels re audiometric zero (ASA-1951 and

ANSI-1 969) for the better ear at 500 Hertz, according to age and sax: United Statas, 1966-70 .................

Percent distribution of youths by hearing levels in decibels re audiometric zero (ASA-1951 and

ANSI- I 969) for the better ear at 1000 Hertz, according to age and sax: United States, 1966-70 ...............

Percent distribution of youths by hearing levels in decibels re auidometric zero (ASA-1951 and

ANSI-1 969) for the better ear at 2000 Hertz, according to age and sex: United States, 1966-70 ...............

Percent distribution of youths by hearing levels in decibels re audiometric zero (ASA-1951 and

ANSI- I 969) for the better ear at 3000 Hertz, according to aga and sax: United States, 1966-70 . ..............

Percent distribution of youths by hearing levels in decibels re auidometric zero (ASA-1951 and

ANSI-1969) for the better ear at 4000 Herti, according to age and sex: United States, 1966-70 ...............

Percent distribution of youths by hearing levels in decihals re audiometric zero (ASA-1951 and

ANSI- I 969) for the better ear at 6000 Hertz, according to age smd sax: United States, 1966-70 ...............

Percent distribution of youths by hearing levels in decibels re auidometric zero (ASA-1951 and

ANSI- I 969) for the better ear at 8000 Hertz, according to age and sex: United States, 1965-70 ... ............

Pegs

27

30

33

34

35

36

37

38

39

40

41

42

43

44

45

46

25
Tabla

17.

18.

19.

20.

21.

22.

23.

24.

25.

26.

27.

28.

28.

30.

31.

List of Detailed Tables–Con.

Madian hearing levels in decibels re audiometric zero (ASA-1951 and ANSI-1969) for the right. left, and

better ear of youths 12-17 years at each test frequency and estimates for speech, by age: United States,

1956-70 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...........................

Median hearing levels in decibels re audiometric zero (ASA-1951 and ANSI-1969) for the right, left, and

better ear of boys 12-17 years at each test frequency and estimates for qmech, by age: United States,

1966-70 ........ ................................................................................................. ......................................

Median hearing levels in decibels re audiometric zero (ASA-1951 and ANSI-1969) for the right, left, and

better ear of girls 12-17 years at each test frequency and estimates for speech, by age: United States,

196&70 ....... .........................................................................................................................................

Medians and quartile points in the distribution of hearing levels in decibels re audiometric zero

(ANSI-1 969) for the better ear at each test frequency and estimates for speech among w~ youths, by

~e~ United States, 196&70 .........................................................................................................

Medians and quartile points in the distribution of hearing levels in decibels re audiometric zero

(A NSI-1 969) for the better ear at each test frequency and estimatas for speech among Negro youths, by

age and sex: Unitad States, 1966.70 ........ ..................................................................... .............................

Mean hearing levels re audiometric zero (ANSI-1869) at each test frequency and estimates for speech in

the better ear among youths by region, age, and sax: United States, 196&7 O.......................... ..................

Medians and quartile points in tha distribution of hearing levels in decibels re audiometric zero

(ANSI-1 969) for the better e= at each test frequency and estimates for speech among youths in the

Northeast, by age and sex: United States, 1966-70 ................ .................................... ............ .... ........ ........

Medians and quartile points in the distribution of hearing levels in decibels re audiometric zero

(ANSI-1 969) for the batter ear at each test frequency and estimates for speech among youths in the

Midwest —~by age and sex: United States, 1966-70 ................................................................. .... .. ...... .........

Medians and quarti!e points in the distribution of hearing levels in decibels ra audiometric zaro

(ANSI-1 969) for the better ear at each test frequency and astimates for speech among youths in the

South, by age and sex: Unitad States, l%&70 .................................. ........................................................

Medians and quartile points in the distribution of hearing Ievals in decibels re audiometric zero

(ANSI-I 969) for the better ear at each test frequency and estimates for speech among youths in the

West, by age and sex: United States, 1966.70 ................. .............................................................. .............

Mean hearing levels in decibels re audiometric zero (ANSI-1969) for the better ear at each test

frequency among youths in urban and rural areas, by age and sex: United States, 1966-70 .......................

Maen hearing levels in decibels re audiometric zero (ANSI-1969) for the better ear at each test frequency

among youths in urban areas, by population size of place of residence, age, and sax: United States, 1968-

70 ...... ....................................... ..................................................................... .............................................

Mean hearing levels in decibels re audiometric zero (ANSI-1889) for tha battar ear at each test

frequancy and estimates for spaech among youths, by rate of population change in place of residenca

from 1950 to 1960 and age: United Stetes, 1986-70 ............................................................................... ..

Maen hearing Iwels in decibels re audiometric zero (ANSI-1969) for the bettar ear at each test

frequency and estimates for speech among youths by annual family income, age, and sex: United States,

1866-70 ......... .................. ........................ ...... ............................................................................................

Mean hearing levels in decibels re audiometric zero (ANSI-1889) for the better aar at each test

frequency and estimates for speech among youths, by education of parent, age, and sex: United States,

1966-70 ... ............... ............... ........................................ ...... .................................................. ....................

Paga

47

48

49

50

53

E6

59

62

65

68

71

72

73

74

75

26
Tsble 1. Mean hearing levels re audiometric zero (ASA-1951 ) in the better ear of youths at each test frequency and estimatas for speech,

by race, age, and sex: Unitad States, 1966-70

250 Hertz 500 Hertz 1000 Hertz

Total White Negro Other Total White Negro Other Total IIWhite Negro Other

Age and sex

Both sexes

12.17 years . .

12years . . . . .

13years. ..,.

14years . . . . .

15years. ..,.

16years. . , . .

17years. ,,. ,

Boys

12.17 years . .

12 years. . . . .

13 years. . . . .

14years . . . . .

15years. , . . .

16years . . . . .

17years. ., , .

Girls —

12-17 years . .

12years . . . . .

13years, , , , .

14years. . . . .

15years. . . . ,

16yeers. . . . .

17years, . . . .

Decibels re audiometric zero (ASA-I 951)

-8.4 -B.5 -7.4

-10.1

-6.7

-6.9

-5.6

-10.2

-7.0

-6.8

-10.0 -10.0 -10.2 -10,6 -8.2 -8.2 -8.0 -7.4 -7.7

L

-9.9

-9,8

-10.3

-10.1

-10.2

-9.7

-10.0

-10.2

-10.1

-10.3

-10.2

-10.0

-9.5

-10.0

-9.9

-9.6

-10.4

-10.0

-10.1

-9.8

-9.9

-10.0

-9.8

-10.3

-9.8

-10.0

-9.4

-10.0

-9.9

-10.6

-10.0

-10.7

-10.0

-9.4

-11.0

-10.7

-12.1

-10.2

-12.5

-9.9

-10.7

-9.2

-12.8

-8.6

-10.4

-9.6

-16.0

-7.4

-11.2

-7.8

-8.0

-8.2

-8.2

-8.7

-8.6

-8.0

-7.8

-8.2

-8.2

-8.2

-8.7

-8.7

-8.0

-7.7

-B.O

-7.8

-7.6

-8.4

-8.4

-B.6

-7.6

-7.5

-8.0

-8.4

-8.4

-8.3

-8.6

-9.6

-4.4

-5.5

-7.6

-10.7

-8.8

-6.0

-8.0

-8.2

-8.4

-8.5

-8.5

-8.8

-8.2

-8.0

-8.4

-8.5

-8.6

-8.7

-8.8

-8.2

-7.8

-7.1

-8.0

-7.8

-7.3

-8.0

-7.9

-7.5

-8.6

-7.8

-9.8

-8.6

-9.6

-7.5

-4.6

-3.6

-6.2

-5.8

-10.8

-5.3

-9.2

-11.3

-7.5

-2.5

-8.6

-10.4

-9.2

-7.8

-8.0

-8.2

-8.4

-8.4

-8.4

-8.6

-8.4

-8.6

-8.6

-8.6

-8.7

-9.1

-7.7

-8.0

-8,2

-8.4

-8.5

-8.4

-8.8

-8.4

-8.8

-8.8

-9.0

-8.9

-9.3

-8.1

-7.5

-7.8

-8.6

-7.1

-8.2

-7.5

-7.6

-6.8

-8.2

-7.1

-7.5

-7.8

-4.6

-5.3

-9.4

-6.4

-10.0

-5.3

-8.2

-12.0

-12.5

2.5

-5.2

-10.4

-9.8

-14.6

-8.9

-12.5

-11.0

-17.4

-6.0

-9.8

-7.7

-8.0

-7.8

-7.9

-8.4

-8.6

-8.4

-8.0

-8.1

-8.6

-8.4

-9.0

-8.8

-7.9

-8.4

-8.7

-8.6

-9.1

-9.0

-7.8

-6.5

-8.4

-7.0

-8.3

-7.0

-9.6

-9.5

-10.3

-10.1

-10.2

-9.8

-9.7

-9.6

-10.4

-10.3

-10.3

-10.1

-9.1

-9.2

-9.9

-B.9

-10.2

-8.2

-12.2

-7.5

-2.5

-8.8

-12.5

-9.8

27
Table 1. Mean hearing levels se audiometric zero (ASA-I 951 ) in the batter ear of youths at each teat frequency end estimates for spaa&,

by race, age, and sax: Unitad Statas, 1666-70-Con.

2000 Hertz 3000 Hertz 4000 Hertz

Total White Negro Other Total White Negro Other Total White Negro Other

Age and sex

Both sexes Decibels re audiometric zero (ASA-1 951)

12-17 years . .

12 years. . . . .

13years. , . . .

14years. . . . .

15years. . . . .

16 years. . . . .

17years. . . . .

Boys

12-17 years . .

12yaars. . . . .

13years. . . . .

14 years. . . . .

15years. . . . .

16yaars. . . . .

17 years. . . . .

Girls

12-17 years . .

12yaars. . . .“.

13years. . . . .

14years. . . . .

15years. . . . .

16yaars. . . . .

17years. . . . .

-8.0 -8.2

-B.l -B.2

-8.1 -B.4

-8.0 -8.1

-7.8 -B.O

-8.2 -8.4

-8.2 -8.4

-7.6 -7.B

-7.4 -7.4

-7.6 -7.8

-7.6 -7.8

-7.5 -7.6

-8.0 -8.2

-7.6 -7.8

-8.5 -8.8

-8.8 -9.1

-B.6 -9.0

-8.3 -B.4

-8.2 -8.5

-8.3 -8,6

-8.B -9.1

-6.8 -7.0 -3.8 -4.1 -1.8 -2.5 -1.1 -1.3 0.0 0.8

-7.0

-6.8

-7.0

-6.4

-6.6

-6.4

-6.7

-7.2

-1.9

-4.4

-9.3

-10.8

-6.6

-7.4

-3.9

-3.6

-3.8

-3.6

-3.9

-4.0

-2,6

-4.3

-4.0

4.2

-3.8

4.2

-4.2

-2.8

-1.5

-1.2

-1.6

-2.0

-2.4

-2.4

-1.4

-5.8

0.6

-1,1

-0.3

-1.4

-8.2

“-2.2

-1.2

-0.8

-1.4

-1.1

-1.2

-1.0

0.1

-1.4

-1.1

-1.6

-1.2

-1.3

-1.2

0.1

0.0

0.8

0.4

-0.8

-0.7

0.6

0.0

-1.1

0.2

-2.0

5.5

0.4

-3,9

1.3

-7.4

-7.0

-6.0

-6.B

-6.5

-6.3

-6.8

-6.6

-4.1

-5.0

-7.7

-12.5

-9.1

-6,6

-2.9

-2.5

-2.6

-2.4

-2.4

-3.0

-5.0

-3.2

-2.7

-2.B

-2.4

-2.6

-3.0

-5.4

-0.8

-1.4

-1.3

-2.1

-1.2

-2.2

-2.2

-7.5

0.2

-0.7

3.0

-2.9

-9.1

-3.0

-0.3

0.2

-0.5

0.2

0.2

0.8

-2.4

-0,3

0.1

-0.6

0.2

0.2

1.0

-2.8

-0.3

0.8

0.4

-0.4

-0.2

0.0

0.1

-0.4

-0.3

-3.2

17.0

-4.0

-5.2

0.0

-6.8

-6.4

-8.0

-6.0

-6.8

-6.6

-7.4

7.5

-2.5

-10.2

-6.6

-2.5

-5.0

4.8

-5.0

-4.8

-5.4

-5.1

-5.4

-5.5

-5.5

-5.2

-5.8

-5.5

-2.2

-1.0

-1 .B

-1.8

-3.6

-2.7

-5.1

2.5

-2.5

-2.3

2.2

-7.0

-2.2

-1.9

-2.2

-2.4

-2.6

-2.9

-2.6

-2.4

-2.6

-2.6

-2,8

-3.5

0.3

0.7

0.4

-1.1

-1.2

1.2

-1.3

2,5

2.5

-1,4

11.0

-2.0

28
Tabla 1. Maan hearing Iavals re audiometric zero (ASA-1951 ) in the better ear Of youths at each test frequency and estimates for speech,

by race, age, and sex: United States, 1966-70–Con.

6000 Hertz 8000 Hertz 1 Speech’

Age and sex

Total White Negro Other Total II White I Negro I Other I Total II White I Negro I Other

Both sexes Decibels re audiometric zero (ASA-I 951)

12-17 years . . 2.0 2.2

1.2

2.0

2.0

2.4

3.2

2.6

0.8 2.5 -7.4 -7.3 -7.8 -10.4 -6.4 -6.4 -5.6 -5.2

12years . . . . .

13years . . . . .

14years . . . . .

15years. . . . .

16years. . . . .

17years . . . . .

1.2

1.8

1,8

2.2

3.0

2.4

0.4

0.6

0.9

1.0

1“.1

1.1

-3.6

0.2

4.1

5.9

10.8

-3.0

-7.1

-7.0

-7.5

-7.2

-8.0

-7.6

-6.6

-6.9

-7.0

-7.5

-7.2

-7.8

-7.5

-6.4

-8.0

-7.0

-7.5

-7.2

-8.7

-8.2

-16.0

-10.8

-12.0

-8.6

-0.5

-15.0

-10.4

-6.1

-6.2

-6.2

-6.2

-6.6

-6.6

-8.0

-6.2

-6.4

-6.2

-6.4

-6.8

-621-

-8.1

-5.6

-5.2

-5.8

-5.4

-5.4

-5.8

-7.5

-1.3

-4.4

4.6

-9.6

-5.1

Boys

12-17 years . . 3.6 -5.8 -4.9

2.3

2.8

3.0

3.6

4.8

5.0

0.5

4.0

2.8

3.2

3.4

3.8

5.2

5.4

0.5

1.0

-0.5

0.8

0.6

1.3

2.0

2.4

0.6

2.2

0.4

-1.5

0.6

13.4

0.8

-1.8

2.8

‘-8.0

-8.2

-7.8

-7.8

-7.6

-9.3

-7.7

-7.5

-23.7

-12.7

-14.4

0.2

-6.1

-14.8

-10.4

-13.2

-2.5

-2.5

-14.0

12.6

-15.3

-5.8

-6.0

-5.9

-6.0

-6.4

-6.2

-6.6

-6.4

-6.5

-6.6

-6.5

-6.8

-7.0

-5.8

-6.0

-6.0

-6.0

-6.5

-6.2

-6.8

-6.6

-6.8

-6.6

-6.8

-7.0

-7.4

-5.8

-5.7

-5.3

-6.4

-5.5

-6.2

-5.3

-5.4

-4.7

-6.=4

-4.6

-5.3

-5.4

-4.6

-1.0

-6.2

-3.6

-10.4

-5.3

-5.8

-8.6

-2.5

2.5

-5.2

-7.5

-4.8

12years . . . . .

13yearsm . . . .

14years, , . . .

15years. . . . .

16years . . . . .

17years . . . . .

-6.4

-6.2

-7.2

-8.4

-6.7

-6.8

-8.2

-6.0

-6.0

-7.0

-6.2

-6.4

-6.6

-8.3

Girls

12-17 years . .

-7.8

-7.8

-7.9

-8.1

-9.2

-8.4

-7.8

-8.0

-8.0

-8.2

-9.4

-8.4

-7.8

-6.2

-7.2

-6.9

-8.1

-8.6

12yearsm . . . .

13years. ..m.

14years, . . . .

15years ...,.

16years . . . . .

17years . . . . .

0.0

0.6.

0.6

0.9

1.2

-0.2

-0.2

0.6

0,6

0,9

1.2

-0.2

1.3

0.3

1.2

0.8

0.2

-0.2

-5.1

7.5

17,5

1.2

34.8

-4.8

1Avaraga of ha~ring levels at 500, 1000, and 2ooo Hertz.

29
Table 2. Mean haaring levals re audiometric zero (ANSI-1969) in the better ear of youths at each test frequency and astimatas for

speech, by race, age, and sex: United Statas, 1966-70

Age and sex

Both sexes

12-17 years . .

12years. . . . .

13years. . . . .

14years. . . . .

15years. . . . .

16years . . . . .

17years. . . . .

~

12-17 years . .

12years. . . . .

13years. . . . .

14years. . . . .

15years. . . . .

16years. . . . .

17years. . . . .

12-17 years . .

12years. . . . .

13years. . . . .

14years. . . . .

15years. . . . .

16yaars. , . . .

17 years. . . . .

250 Hertz

Total White Negro Other

9.2 9.2

9.2 9.4

9.4 9.6

8.8 8.7

9.0 9.1

9.0 9.1

9.4 9.4

9.1 9.3

9.0 9.2

9.2 9.6

8.7 8.8

9.0 9.3

9.2 9.3

9.6 9.8

9.2 9.2

9.4 9.5

9.7 9.7

8.8 8.7

9.0 8.8

9.0 9.0

9.2 9.0

8.8

9.0

8.2

9.0

8.2

8.8

9.2

7.8

8.4

6.7

8.7

6.5

8.8

7.9

9.6

9.6

9.6

9.2

10.0

8.9

10.5

500 Hertz

Total White Negro Other

Decibels re audiometric zero (ANSI-1869)

8.2

4.6

10.4

8.6

9.4

1.8

12.6

7.6

5.4

9.8

6.2

7.8

-0.6

14.0

9.0

4.3

12.5

17.5

10.4

7.5

10.2

5.9 5.9

6.4 6.4

6.2 6.2

5.8 5.8

6.0 6.0

5.5 5.6

5.4 5.4

6.1 6.2

6.6 6.5

6.3 6.4

6.3 6.3

6.2 6.4

5.8 6.9

5.6 5.8

5.6 5.6

6.2 6.3

6.0 6.8

5.4 5.4

5.7 5.5

5.2 5.1

5.4 5.2

5.8

6.2

6.3

6.0

5.6

5.5

5.4

5.2

6.6

5.2

6.2

4.2

5.2

4.0

6.4

5.8

7.3

5.7

6.9

5.8

6.6

6.3

2.9

9.6

8.6

6.5

2.1

8.2

7.8

10.4

10.2

7.5

8.0

1.0

9.7

4.6

0.2

7.5

12.5

5.6

4.6

5.8

1000 Hertz

Total White Negro Other

1.6 1.4

2.0 2.0

1.8 1.6

1.6 1.5

1,5 1.4

1.4 1.3

1.2 1.2

1.8 1.8

2.2 2.3

2.0 2.0

1.8 1.8

1.6 1.6

1.6 1.5

1.6 1.6

1.4 1.2

1.6 1.6

1.4 1.1

1.4 1.2

1.4 1.0

1.3 1.1

0.9 0.7

2.3

2.2

2.9

2.0

2.2

2.6

2.0

2.1

1.9

2.5

2.2

1.4

2.9

1.8

2.5

2.4

3.2

1.8

2.9

2,4

2.2

2.6

-0.1

3.3

3.1

4.4

-0.2

3.0

3.2

5.4

4.7

0.6

3.6

0.0

4.7

1.8

-2.0

-2.6

12.6

4.8

-0.4

0.2

30
Tabla 2. Mean hearing Ievalsra audiometric zaro (ANSI-1969) in tha batter ear of youths at each test frequency and estimates for

speech, by rata, age, and sex: United States, 1966-70-Con.

Age and sex

2000 Hertz 3000 Hertz 4000 Hertz

Total ]I White I Nagro I Other Total White Negro Other Total White Negro Other

Both sexes

12-17 years . .

12years. . . . .

13years. . . . .

14years. . . . .

15years. . . . ,

16years. . . . .

17 years. . . . .

Boys

12-17 yaars . .

12years. . . . .

13years. . . . .

14years. . . . .

15years. . . . .

16years. . . . .

17vears. . . . .

Girls

12-17 years . .

12years. . , , ,

13years. . . . .

14 years. , . . .

15years. . , . .

16years. . , , .

17years. . . . .

Decibels re audiometric zero (ANSI-1869)

1.1

1.1

1.1

1.1

1.2

1.0

1.0

1.6

1.8

1.6

1.4

1.6

1.2

1.6

0,6

1.0

1.0

1.0

1.0

1,1

0.8

0.8

1.4

2.2

1.8

2.0

2.0

2.6

2.2

2.2

2.2

1.7

. 0.2

7.1

4.5

-0.2

-3.0

3.4

1.3

5.3 5.0 7.0 6.2 9.0 9.2

1

8.0 7.8

8.0 7.8

8.4 8.2

7.7 7.4

8.0 7.9

8.0 7,9

8.0 7.9

9.2 9.2

8.9 9.0

9.4 9.4

8.5 8.4

9.2 9.2

9.2 9.4

9.9 10.1

6.8 6.4

7.0 6.6

7.2 6.9

6.8 6.4

6.7 6.6

6.6 6.4

6.2 5.6

5.2

5.6

5.2

5.6

5.2

5.0

6.5

4.9

5.2

4.8

5.3

5.1

4.9

6.4

7.4

7.6

7.4

7.0

6.4

6.2

7.4

1.7

9.6

7.9

8.7

6.4

1.8

6.6

8.9

9.6

9.4

8.2

8.2

9.2

8.9

6.4

9.2

7.0

13.4

8.2

6,1

9.5

1.8

1.6

1.2

1.5

1.0

1.4

0.4

1.8

1.8

2.9

2.2

2.2

2.4

2,1

1.9

2.4

1.0

2.9

2.4

2.2

3.4

4.6

3.8

1.1

-5.7

0.9

2.2

-0.8

17.5

7.5

-1.0

3,4

7.5

6.3

&8

6.4

6.7

6.8

6.2

4.1

4.2

4.3

4.0

4.4

3.8

4.0

6.0

6.6

6.2

6.6

6.6

6.2

3.7

3.8

3.7

3.6

4.0

3.5

3.6

8.4

7.3

7.6

6.8

7.6

6.4

6.7

6.4

7.8

7.2

7.0

5.4

6.0

2.5

8.9

8.0

11.8

3.9

0.9

5.8

1.4

12.5

7.5

6.8

12.2

3.0

8.8

9.6

9.4

8.5

8.4

8.6

‘9.0

9.6

8.4

5.6

22.9

2.8

4.8

8.8

5.2

12.5

12.5

7.7

21.0

8.0

0.4

0.6

0.8

1.0

0.9

0.4

0.2

0.2

0.7

0.6

0.7

0.0

9.0

9.5

9.4

7.8

8.0

9.9

31
Tabla 2. Mean hearing levels re audiometric zero (ANSI-1989) in the better ear of youths at each test frequency and estimatesfor

speech, by race, age, and sex: United States, 1966-70–Con.

6000 Hertz 8000 Hertz Speech 1

Totel White Negro Other Total White Negro Other Total White Negro Other

Age and sex

Both sexes

12-17 years . .

12years. . . . .

13years. . . . .

14years. . . . .

15years. . . . .

16years. . . , .

17years. . . . .

Boys

12-17 years . .

12years. . . . .

13years. . . . ,

14years. . . . .

15years. . . . .

16years. . . . .

17years. . . . .

Girls —

12-17 years . .

12years. . . . .

13years. . . . ,

14years. . . . .

15years. , . . ,

16yaars. . . . .

17years. . . . .

Dacibels re audiometric zero (ANSI-1889)

11.2 11.4

10.4

11,2

11.0

11.5

12.5

11.7

13.0

11.9

12.5

12.4

12.9

14.4

14.4

9.6

9.0

9.9

9.6

10.1

10.4

9.0

9.7

9.2

9.3

9.9

10.0

10.0

9.8

9.9

8,6

9.5

9.6

10.2

10.8

11.0

9.5

10.0

9.2

10.2

9.7

9,2

8.6

10.7 6.7 6.8 6.1 3.2

-3.6

3.2

2.0

4.8

12.2

0.0

3.0

5.0 5.0 5.6 5.8

4.4

9.6

7.0

6.1

0.4

6.6

6.1

10.2

11.0

10.9

11.4

12.2

11.4

12.6

11.4

12.0

12.0

12.6

14.0

14.0

9.6

9.0

9.8

9.8

10.0

10.4

8.9

3.8

9.2

13.1

13.8

16.8

7.0

10.4

10.4

7.3

9.3

19.4

7.6

8.2

11.0

1.4

17.5

27.5

10.4

38.8

5.2

7,0

7.2

6.5

6.8

6.2

6.4

7.5

7.3

7.3

6.6

6.9

6.4

6.6

7.8

5.8

6.8

6.4

6.6

5.2

5.5

5.8

5.4

5.2

5.1

5.1

4.8

4.8

5.4

5.4

5.0

5.0

5.0

4.6

4.7

5.4

5.6

6.0

5.7

5.8

5.4

5.4

5.4

7.8

8.o

6.8

7.6

7.4

7.2

6.0

6.2

6.4

6.2

6.0

5.0

5.6

8.1

8.3

7.0

7.8

7.9

7.4

5.8

5.9

6.0

6.2

6.4

4.4

5.9

6.4

-8.7

1.1

-0.7

12.4

5.8

0.2

3.4

5.8

5.4

5.4

5.4

5.0

5.2

4.8

5.8

5,4

5.2

5.4

5.0

5.2

4.6

5,6

5.2

6.4

5.0

5.2

4.6

6.0

8.4

9.0

5.6

6.4

-0.4

7.5

5.5

6.4

6.2

6.0

6.0

4.8

5.8

5.8

7.6

6.8

7.0

6.0

5.1

-1.8

12.5

12.5

0.2

27.6

-0.3

5.0

5.0

4.8

4.9

4.5

4.4

4.8

4.6

4.8

4,6

4.4

4.2

5.7

6.8

5.0

6.6

5.7

6.1

3.0

12.5

12.5

5.9

2.5

5.2

1Average of hearing Ievalsat 500, 1000, and 2ooo Heflz.

32
Tabla 3. Percent distribution of youths 12-17 years by hearing levels in decibels re audiometric zero (ASA-1951 ) for the right, left,

and better ear at 250,500, 1000,2000,3000.4000, 6000, and 8000 Hertz: United States 1966-70

Ear and tonal frequency

Right ear

250 Hertz . . . . . . . .

600 Hertz . . . . . . . .

1000 Hertz . . . . . . . .

2000 Hertz . . . . . . . .

3000 Hertz . . . . . . . .

4000 Hertz . . . . . . . .

6000 Hertz . . . . . . . .

8000 Hertz . . . . . . . .

Left eer

250 Hertz....,,..

500 Hertz....,,.,

1000 Hertz . . . . . . . .

2000 Hertz, . . . . . . .

3000 Hertz . . . . . . . .

4000 Hertz . . . . . . . .

6000 Hertz . . . . . . . .

8000 Hertz.....,..

8etter ear

250 Hertz . . . . . . . .

500 Hertz . . . . . . . .

1000 Hertz . . . . . . . .

2000 Hertz . . . . . . . .

3000 Hertz ..,.,...

4000 Hertz . . . . . . . .

6000 Hertz . . . . . . . .

8000 Hertz, . . . . . . .

I

All

-25

levels

or

less

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

0.0

0.0

0.1

0.0

0.0

0.6

0.1

0.0

0.0

0.1

0.0

0.0

0.0

0.5

0.1

0.1

0.1

0.1

0.0

0.0

0.0

1.0

I

-24 -14

to to

-15 -5

Hearing levels in decibels

12.7

5.9

5,5

8.0

2.1

0.6

0.7

12.4

10.7

5.1

4.8

7.0

1.5

0.3

0.4

11.3

17.2

8.9

8.6

12.2

3.0

0.8

1.0

18.1

65.2

61.0

62.2

64.5

35.2

22.1

15.2

39.8

58.3

59.6

59.7

51.4

32.3

16.8

11.8

39.1

67.1

66.9

69.0

60.6

44.8

29.9

21.3

47.0

Percent distribution

18.7

28.1

26.6

30.6

.47.4

54.6

42.1

31.8

26.9

29.6

29.6

33.7

48.1

52.4

39.1

33.5

14.1

21.5

19.6

23.3

42.8

54.7

47.5

26.3

2.2

3.6

3.8

5.0

11.6

16.8

28.4

9.6

2.9

4.3

4.1

5.7

13.6

22.9

32.1

9.8

1.0

2.1

2.0

3.0

7.5

11.3

22.9

5.1

0.6

0.7

1.0

0.7

1.8

2.8

7.8

2.5

0.8

0.8

1.2

1.3

2.4

4.1

10.2

2.9

0.3

0.3

0.5

0.4

1.0

1.8

4.7

1.2

0.3

0.3

0.3

0.6

0.8

1.2

2.6

1.3

0.2

0.4

0.3

0.4

1.1

1.6

3.1

1.3

0.2

0.2

0.2

0.3

0.5

0.7

1.0

0.5

0.1

0.1

0.1

0.2

0.4

0.7

1.2

0.7

0.1

0.1

0.1

0.2

0.5

0.7

1.2

0.6

0.0

0.0

0.1

0.2

0.3

0.7

0.3

+46

to

+55

0.1

0,2

0.1

0.1

0.3

0.6

1.3

0.8

0.0

0.1

0.1

0.1

0.2

0.6

1.3

0.6

0.0

0.0

0.0

0.0

0.1

0.3

0.6

0.3

+56

or

more

0.1

0.1

0.3

0.3

0.4

0.6

0.7

0.5

0.0

0.0

0.1

0.1

0.3

0.6

0.8

0.4

0.0

0.0

0.0

0.0

0.1

.0.2

0.3

0.2

33
Table 4. Percent distribution of ~ 12-?7 yeers by hearing levels in decibels ra audiometric zero (ASA-1951 ) for the right, left, ●nd

batter ear at 250,500, 1000,2000,3000,4000, 6000, and 8000 Hertz: Unitad States, 1965-70

Ear and tonal frequency

Right ear

250 Hertz . . . . . . . .

500 Hertz . . . . . . . .

1000 Hertz . . . . . . . .

2000 Hertz . . . . . . . .

3000 Hertz . . . . . . . .

4000 Hertz . . . . . . . .

6000 Hertz . . . . . . . .

8000 Hartz . . . . . . . .

Left ear

250 Hertz . . . . . . . .

500 Hertz . . . . . . . .

1000 Hertz . . . . . . . .

2000 Hertz . . . . . . . .

3000 Hertz . . . . . . . .

4000 Hertz . . . . . . . .

6000 Hertz . . . . . . . .

8000 Hertz . . . . . . . .

Better ear

250 Hertz . . . . . . . .

500 Hartz . . . . . . . .

1000 Hertz . . . . . . . .

2000 Hertz . . . . . . . .

3000 Hartz . . . . . . . .

4000 Hertz . . . . . . . .

6000 Hertz . . . . . . . .

,8000 Hertz . . . . . . .

Hearing levels in decibels

All

-25 -24 -14 -4 +6 +16 +26 +36 +46 +56

levels ‘r

to to to to to to to to or

less -15 -5 +5 +15 +25 +35 +45 +55 more

Percent distribution

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

0.1

0.1

0.1

0.1

0.0

0.4

0.1

0.1

0.0

0.0

0.0

0.6

0.1

0.1

0.1

0.1

0.0

0.0

0.9

12.0

5.0

5.4

8.0

1.4

0.4

0.3

11.5

10.6

4.7

4.1

6.3

0.9

0.2

0.2

10.4

16.7

8.0

8.0

11.3

2.0

0.6

0.5

17.1

66.3

61.0

61.7

53.3

31.0

19.1

13.1

37.8

58.8

57.9

58.2

48.9

26.4

13,6

9.4

36.6

68.5

67.0

68.2

59.1

39.2

25.8

18.1

45.6

18.5

28.5

27.1

30.4

49.6

54.3

38.3

32.0

26.7

31.7

31.2

34.7

50.0

49.9

36.0

33.7

13.4

22.2

20.8

24.3

47.3

55.8

45.9

27.1

1.9

3.8

3.8

6.2

13.2

17.9

30.9

10.7

2.8

4.3

4.4

7.2

16.3

25.5

33.1

10.4

0.8

2.0

1.9

4.1

8.9

12.9

25.8

5.8

0.6

1.0

1.2

0.7

2.4

3.7

8.9

3.2

0.6

0.8

1.4

1.8

3.3

5.4

12.3

4.1

0.3

0.5

0.7

0.6

1.4

2.6

5.8

1.8

0.4

0.3

0.3

0.8

1.1

1.7

3.4

1.6

0.3

0.4

0.4

0.6

1.6

2.4

4.2

1.8

0.2

0.2

0.3

0.4

0.8

1.1

1.3

0.5

0.1

0.1

0.1

0.2

0.6

1.2

1.9

1.0

0.1

0.0

0.1

0.3

0.8

1.1

1.6

0.8

0.0

0.1

0.2

0,4

1.1

0.4

0.1

0.1

0.1

0.1

0.3

0.8

2.1

1.1

0.1

0.1

0.1

0.4

0.9

1.9

0.9

0.0

0.1

0.4

0.9

0.4

0.0

0.1

0.2

0.2

0.4

0.9

1.1

0.7

0.0

0.0

0.1

0.1

0.3

1.0

1.3

0.7

0.0

0.0

0.0

0.1

0.4

0.6

0.4

34
Tabla 5. Parcent distribution of Q& 12-17 years by hearing levels in decibels re audiometric zero (ASA-1951 ) for the right, left, and

better ear at 250,500, 1000, 2000,3000,4000,6000, and 8000 Hertz: United States, 1966-70

Ear and tonal frequency

Right ear

250 Hertz . . . . . . . .

500 Hertz ...,....

1000 Hertz, ..,....

2000 Hertz . . . . . . . .

3000 Hertz ..,.....

4000 Hertz . . . . . . . .

6000 Hertz . . . . . . . .

8000 Hertz,.,.,,..

Left eer

250 Hertz . . . . . . . .

500 Hertz . . . . . . . .

1000 Hertz ..,.....

2000 Hertz . . . . . . . .

3000 Hertz . . . . . . . .

4000 Hertz . . . . . . . .

6000 Hertz . . . . . . . .

8000 Hertz . . . . . . . .

Better ear

250 Hertz . . . . . . . .

500 Hertz ..,.....

1000 Hertz . . . . . . . .

2000 Hertz . . . . . . . .

3000 Hertz . . . . . . . .

4000 Hertz . . . . . . . .

6000 Hertz . . . . . . . .

8000 Hertz . . . . . . . .

m

100.0

100.0

100.0

100.0

100,0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

0.0

0.1

0.0

0.8

0.0

0.0

0.0

0.2

0.0

0.0

0.0

0.5

0.1

0.1

0.1

0.0

0.0

0.0

1.1

13.3

6.8

5.7

8.0

2.8

0.7

1,1

13.4

10.7

5.5

5,5

7.8

2.1

0.4

0.5

12.2

17.8

9.9

9.2

13.1

4.1

1.1

1.5

19.1

Hearing levels in decibels

A1-!L

64.1

61.0

62.9

55.7

39.5

25.1

17.3

41,9

57.8

61.4

61.2

53.9

38.4

20.1

14.2

41.6

65.7

66.7

69.9

62.1

50.5

34.1

24.5

48.5

+6 I +16

to I

to

+15 +25

Percent distribution

18.8

27.6

26.0

30.8

45.0

54.8

45.9

31.6

27.0

27.4

28.0

32.6

46.1

55.0

42.4

33.2

14.7

20.8

18.2

22.2

38.2

53.6

49.3

25.5

2.6

3.2

3.7

3.7

10.0

15.7

25.8

8.5

3.1

4.4

3.9

4.1

10.8

20.2

31.1

9.1

1.3

2.2

2.1

1.8

6.1

9.7

19.9

4.4

0.6

0.5

0.8

0.7

1.2

1.9

6.8

1.8

1,0

0.8

0,8

0,8

1.5

2.7

8.1

1.6

0.3

0.2

0.4

0.3

0.6

1.0

3.5

0.6

+26

to

+35

0.2

0.3

0.3

0.5

0.5

0.7

1.7

0.9

0.2

0.3

0.2

0.2

0.6

0.7

2.1

0.8

0.1

0.1

0.1

0.2

0.3

0.3

0.8

0.4

+36

to

+45

0.2

0.2

0.1

0.2

0.3

0.3

0.5

0.3

0.1

0.1

0.1

0.2

0.2

0.4

0.7

0.4

0.0

0.1

0.1

0.1

0.0

0.3

0.2

I

+46 +56

to or

+55 more

0.0

0.2

0.1

0.1

0.3

0.4

0.6

0.5

0.1

0.1

0.1

0.1

0.1

0.3

0.6

0.4

0.0

0.0

0.0

0.0

0.0

0.2

0.2

0.2

0.2

0.2

0.3

0.3

0.4

0.4

0.3

0.3

0.2

0.1

0.2

0.2

0.3

0.2

0.0

0.1

0.1

0.0

0.0

35
Table 6. Percent distribution of youths 12-17 years by hearing levels in decibels re audiometric zero (ANSI-1969) for the right, left,

and batter ear at 250,500, 1000,2000,3000,4000, 6000, and 8000 Hertz: Unitad States, 1866-70

Ear and tonal frequency

Right ear

250 Hertz . . . . . . . .

500 Hertz . . . . . . . .

1000 Hertz . . . . . . . .

2000 Hertz . . . . . . . .

3000 Hertz . . . . . . . .

4000 Hertz . . . . . . . .

6000 Hertz . . . . . . . .

8000 Hertz . . . . . . . .

Left ear

250 Hertz . . . . . . . .

500 Hertz . . . . . . . .

1000 Hertz . . . . . . . .

2000 Hertz . . . . . . . .

3000 Hertz . . . . . . . .

4000 Hertz . . . . . . . .

6000 Hertz . . . . . . . .

8000 Hertz . . . . . . . .

Better ear

250 Hertz . . . . . . . .

500 Hertz . . . . . . . .

1000 Hertz . . . . . . . .

2000 Hertz . . . . . . . .

3000 Hertz . . . . . . . .

4000 Hertz . . . . . . . .

6000 Hertz . . . . . . . .

8000 Hertz . . . . . . . .

Hearing levels in decibels

Ail

-25 -24 -14 -4 +6 +16 +26 +36 +46 +56

levels

or to to to to to to to to or

less -15 -5 +5 +15 +25 +35 +45 +55 more

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

0.0

0.0

0.0

0.0

0.0

0.0

0.1

0.1

0.0

0.0

0.1

0.0

0.0

0.0

0.1

0.0

0.0

0.0

0.1

0.0

0.0

0.1

0.2

0.0

0.0

0.0

0.2

0.5

0.6

5.5

9.8

2.4

1.0

1.1

4.6

0.6

0.6

4.8

9.1

1.8

0.6

0.6

4.3

0.9

1.1

8.6

15.1

3.6

1.6

1.4

7.3

Percent distribute

18.2

37.4

62.2

57.5

39.6

26.6

17.2

29.9

16.6

34.8

59.7

54.1

36.2

20.8

14.2

28.4

23.2

46.9

69.0

62.0

49.5

34.8

24.1

38.8

61.0

52.1

26.6

26.7

45.3

52.0

43.3

39.3

53.5

52.6

28.6

30.1

46.6

50.9

40.8

40.8

61.6

46.0

19.5

19.6

39.6

50.7

47.7

39.2

17.0

7.7

3.8

4.1

9.5

14.7

26.1

17.8

25.4

9.8

4.1

4.6

11.5

20.6

29.3

17.9

12.9

5.1

2.0

2.4

5.8

9.8

20.1

10.6

2.2

1.4

1.0

0.6

1.4

2.7

6.8

4.5

2.8

1.4

1.2

1.2

2.1

3.7

9.0

4.7

1.0

0.7

0.5

0.4

0.7

1.6

4.7

2.3

0.5

0.3

0.3

0.6

0.8

1.1

2.4

1.5

0.8

0.5

0.3

0.4

1.0

1.5

3.0

1.6

0.2

0.1

0.2

0.3

0.5

0.7

1.0

0.6

0.3

0.1

0.1

0.2

0.3

0.7

1.1

0.7

0.2

0.2

0.1

0.2

0.4

0.7

1.1

1.0

0.2

0.1

0.0

0,0

0.1

0.3

0.7

0.4

0.3

0.4

0.4

0.4

0.7

1.2

2.0

1.6

0.1

0.1

0.2

0.2

0.5

1.2

2.0

1.2

0.0

0.0

0.1

0.0

0.2

0.5

0.9

0.6

36
Tabla 7. Percept distribution of boys 12-17 years by hearing levels in decibels re audiometric zero (ANSI-1969) for tha right, left, and

Mter ear at 2K500, 1000,2000,3000,4000, 6000, and 8000 Hertz: United States, 1966-70

Eisr and tonal frequency

Right ear

250 Hertz, . . . . . . .

500 Hertz ...,,...

1000 Hertz . . . . . . . .

2000 Hertz . . . . . . . .

3000 Hertz ...,....

4000 Hertz.....,..

6000 Hertz . . . . . . . .

800 CrHertz . . . . . . . .

Left ear

250 Hertz . . . . . . . .

500 Hertz . . . . . . . .

1000 Hertz, . . . . . . .

2000 Hertz . . . . . . . .

3000 Hertz . . . . . . . .

4000 Hertz . . . . . . . .

6000 Hertz . . .. . . . . .

8000 Hertz . . . . . . . .

Better ear

250 Hertz . . . . . . . .

!500 Hertz, ,. . . . . .

1000 Hertz . . . . . . . .

2000 Hertz . . . . . . . .

3000 Hertz ...,....

4000 Hertz . . . . . . . .

6000 Hertz . . . . . . . .

BOOO Hertz . . . . . . . .

Hearing levels in decibels

All

-25 -24 -14 -4 +6 +16 +26 +36 +46 +56

levels

or to to to to to to to to or

less -15 -5 +5 +15 +25 +35 +45 +55 more

Parcent distribution

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

.-

0.0

0.0

0.0

0.0

0.1

0.1

0.0

0.0

0.1

0.0

0.1

0.1

0.1

0.1

0,0

0.1

0.7

0.5

5.4

9.7

1.5

0.8

0.5

4.1

0.7

0.7

4.1

8.2

1,1

0.4

0.4

4.0

1.1

1.0

8.o

14.0

2.3

;:;

6.8

17.4

35.9

61.7

56.1

34.8

23.6

15.0

28.7

16.1

31.8

58.2

51.8

30.0

17.4

11.4

26.2

22.1

44.4

68.2

60.7

43.8

30.7

21.1

37.5

62.1

53.1

27.1

27.1

48.3

51.9

40.0

38.3

54.5

55.6

31.2

31.4

49.1

48.9

38.2

39.5

63.4

48.4

20.8

21.0

44.5

51.9

46.4

39.0

16.9

8.4

3.9

5.2

11.2

15.8

28.5

18.1

25.0

9.7

4.4

5.9

14.1

23.2

30.3

18.8

12.2

5.1

1.9

3.2

7.2

11.5

22.8

11.2

1.8

1.6

1.2

0.5

1.8

3.5

7.8

5.5

2.7

1.4

1.4

1.6

3.0

4.9

11.1

5.9

0.8

0.7

0.7

0.5

1.0

2.4

5.1

3.1

0.5

0.2

0.3

0.8

1.1

1.6

3.2

1.9

0.6

0.5

0.4

0.6

1.3

2.2

4.0

2.3

0.2

0.2

0.3

0.4

0.7

1.0

1,2

0.8

0.4

0.1

0.0

0.2

0.5

1.2

1.8

1.0

0.3

0.1

0.1

0.3

0.7

1.1

1.5

1.4

0.2

0.1

0.0

0.1

0.2

0.5

1.1

0.5

0.2

(J.~

0.3

0.3

0.8

1.6

3.2

2.4

0.1

0.1

0.2

0.2

0.7

1.9

3.1

1.8

0.0

0.0

0.0

0.0

0.3

0.9

?.6

1.0

37
Tabla 8. Parcant distribution of girls 12-17 years by hearing Iavalsin decibels re audiometric zero (ANSI-1869) for the right, left, and

bettar ear at 2~500, 1000,2000,3000,4000, 6000, and 8000 Hertz: United States, 1966-70

Ear and tonal frequency

Right ear

250 Hertz . . . . . . . .

500 Hertz . . . . . . . .

1000 Hertz . . . . . . . .

2000 Hertz . . . . . . . .

3000 Hertz . . . . . . . .

4000 Hertz . . . . . . . .

6000 Hertz . . . . . . . .

8000 Hertz . . . . . . . .

Left ear

250 Hertz . . . . . . . .

500 Hertz . . . . . . . .

1000 Hertz . . . . . . . .

2000 Hertz . . . . . . . .

3000 Hertz . . . . . . . .

4000 Hertz . . . . . . . .

6000 Hertz . . . . . . . .

8000 Hertz . . . . . . . .

Better ear

250 Hertz . . . . . . . .

500 Hertz . . . . . . . .

1000 Hertz . . . . . . . .

2000 Hertz . . . . . . . .

3000 Hertz.....,..

4000 Hertz . . . . . . . .

6000 Hertz . . . . . . . .

8000 Hertz . . . . . . . .

Hearing levels in decibels

II I I I I I I

All

-25

levels

or

less

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

100.0

0.0

0.0

-24 -14

to to

-15 -5

0.1

0.0

0.0

0.0

0.2

0.0

0.0

0.2

0.0

0.0

0.0

0.1

0.0

0.1

0.2

0.0

0.1

0.0

0.3

0.4

0.8

5.7

10.0

3.3

1.3

1.6

5.1

0.5

0.4

5.5

10.1

2.5

0.9

0.7

4.6

0.8

1.1

9.2

16.2

4.9

2.0

2.2

7.8

-4

to

+5

*

to

+15

Percent distribution

+16

to

+25

19.1

38.9

62.9

58.9

44.4

28.7

19.4

31.0

17.1

37.9

61.2

56.4

42.6

24.2

17.0

30.7

24.2

49.4

69.8

63.4

55.3

39.0

27.2

40.2

59.9

51.1

25.9

26.4

42.2

52.2

46.6

40.3

52.4

49.5

28.0

28.7

44.0

52.9

43.6

42.1

59.7

43.6

18.2

18.2

34.5

49.5

49.1

39.4

17.0

7.1

3.7

3.1

7.7

13.5

23.7

17.5

25.7

10.0

3.9

3.3

8.8

17.9

28.3

16.9

13.7

5.0

2.1

1,4

4.4

8.1

17.3

9.9

+26

to

+35

2.5

1.1

0.8

0.7

1.0

1.8

5.8

3.5

2.9

1.4

0.8

0.7

1.1

2.5

6.9

3.5

1.2

0.7

0.4

0.2

0.4

0.8

3.0

1.4

+36 +46

to to

+45 +55

0.5

0.4

0.3

0.4

0.5

0.6

1.6

1.2

1.0

0.4

0.2

0.2

0.6

O.B

2.0

0.8

0.3

0.0

0.1

0.3

0.3

0.3

0.7

0.5

0.2

0.1

0.1

0,1

0.2

0.2

0.4

0.3

0.2

0.2

0.1

0.2

0.1

0.4

0.7

0.6

0.1

0.1

0.1

0.1

0.3

0.3

+56

or

more

0.4

0.5

0.5

0.4

0.7

0.7

0.9

0.9

0.2

0.2

0.3

0.2

0.3

0.4

0.8

0,7

0.0

0.1

0.1

0.1

0.1

0.1

0.2

0.2

*

38
Table 9. Percent distribution of vouths by hearing levels in decibels re audioritetric zero (ASA-I 951 and ANSI-I 969) for the better ear

at 250 Hekz, acc&ding to age end sax: United States, 1966-70.

———

Sex and heating

levels In decibels

Total,

12-17 ‘2 ‘3 ‘4 ‘5 ‘6 ‘7

years

years years years years years years

rotal,

12-17 ‘2 ‘3 ‘4 ‘5 ‘6 ‘7

years years years years years years

years

Both sexes Percent distribution (ASA-I 951) Percent distribution (ANSI-I 969)

Allirwels. ,, . . .

-250r less . . . . . . .

-24to -15 . . . . . . .

-14 to -05 .,,,...

-04to +05 . . . . . . .

+06to +15,,,.,,.

+16to +25, ..,.,,

+26to +35 . . . . . . .

+36 and greater . . . .

Boys

All levels . , , . , .

-250r less ,., .,,.

-24to-15 . . . . . . .

-14t0 -05 . . . . . . .

-04to +05..,.,..

+06to +15....,..

+16to +25,,,.,..

+26to +35 . . . . . . .

+36 and greater . . , .

Girls

Ail levels . . . . . .

-250r less . . . . . . .

-24to -15 . . . . . . .

-14tc) -05, . . . . . .

-04to+05 . . . . . . .

+06to +15..,.,,.

+16to +25..,.,.,

+26to +35, . . . . . .

+36 end greeter . . . .

100.0

_

0.1

17.2

67.1

14.1

1.0

0.3

0.2

0,0

100.0

100.0 ~

0.2

17.9

65.6

14.6

1.3

0.3

0.1

0.0

100.0

100.0

0.1

17.5

84.8

15.9

1.4

0,2

0.1

100.0

100.0

0.3

17.6

68.3

12.8

0,7

0.2

0.1

100.0

100.0

18.8

65.5

14.5

0.6

0,5

0.1

100.0

100.0

16.0

70.2

12.3

1.1

0.1

0.2

0.1

100.0

1Oo.c

15.4

68.7

14.1

1.1

0,2

0.5

100.0

100.0

—

0.0

0.9

23.2

61.6

12.9

1.0

0.4

I 00.0

100.0

1.1

23.0

61.0

13.2

1.3

0.4

100.0

100.0

I.0

21.9

60.El

14.7

1.3

0.3

100.0

I00.0

0.1

1.1

24.1

62.4

11.2

0.7

0.4

100.0

IOo.c

=

0,7

25.E

58,E

13,7

0.7

(j.~

100.0

100.0

1.0

22.0

63.7

11.8

1.1

0.4

100.0

I00.0

0.6

21.9

63.0

12,8

1,1

0.6

100.0

0,1

16,7

88.5

13.4

0,8

0.3

0.2

0.0

100.0

0.1

17.8

65.7

14.7

1.3

0.3

0.1

0.0

0.2

19.5

65.9

13.2

0.7

0,3

0.1

0.,1

100.0

0.2

16.1

65.3

16.1

1.9

0.4

0,1

17.4

66.7

15.2

0.5

0.1

—

Ioo.o

0.1

17.7

62.8

16.5

2.4

0.4

0.1

0,3

15.3

72.8

10.5

0.9

0.1

0.1

I 00.0

0.2

19.9

63.6

15.3

0.5

0.3

0.2

—

15,1

71.5

12.2

0.8

0.4

—

100.0

—

1fX9

69,0

12.4

1.4

0.2

—

0.1

14.0

58.9

14.8

1.0

0.5

0.8

100.0

—

16.8

68.5

13.4

1.1

0.2

—

—

1.1

22.1

63.4

12.2

0.8

0.4

I00.0

—

0.0

0.8

24.2

59.7

13.7

1.2

0.4

0.8

24.5

61.4

12.1

0.8

0.4

100.0

—

—

1.4

21.5

6CL7

14.3

1.7

0.4

1.4

20.4

63.7

13,9

0.5

0.1

100.0

0.6

23.6

57.7

15.6

2.1

0.4

18.3

65,6

14.7

0.8

0.6

—

100.0

—

19.4

65.3

14.3

0.4

0.3

0.3

—

1.2

22.5

66.8

8.4

0.9

0,2

100.0

—

0.2

1.1

25.7

58.0

14.0

0.5

0.5

1.3

24.0

59.5

13,8

0.9

0.5

00.0

—

—

0.1

27.5

57.8

13.6

0.4

0.6

—

—

1.2

20.3

65.6

11,7

0.8

0.4

I 00.0

—

0.7

23.8

61.7

12.0

1.5

0.3

—

0.5

20.6

63.4

13.2

1.3

1.0

I00.0

—

—

0.7

23.3

62.6

12.3

0.9

0.2

39
Table 10. Percent distribution of youths by hearing levels in decibels re audiometric zero (ASA-1951 and ANSI-1969) for the better

ear at 500 Hertz, acmrding to age and sex: United States, 1966-70

Total,

12-17

years

12

years

13

years

14

years

15

years

16 17

years years

Total,

12-17

years

12

years

13

years

14

years

15

years

16

years

17

years

Sex and hearing

levals in decibels

Both sexes

I

Percant distribution (ASA-1 951) Percent distribution (ANSI-1 969)

All Iavels . . . . . . 100.0

0.0

8.9

66.9

21.5

2.1

0.3

0.2

0.1

100.0

0.1

8.0

67.0

22.2

2.0

0.5

0.2

0,0

100.0

9.9

66.7

20.8

2.2

0.2

0.1

0,1

100.0

—

8.4

64.8

23.0

3.2

0.2

0.2

0.2

100.0

—

8.2

64.1

24.5

2.4

0.4

0.3

0,1

100.0

100.0

0.1

8.1

67.1

22.5

1.7

0.2

0.3

100.0

0.2

7.4

65.9

24.3

1.7

0.1

0.4

100,0

100.0

10.9

68.3

18.5

1.6

0.6

0.1

100.0

9.9

69.1

18.3

1.5

1.2

—

100.0

11.8

67.5

18.7

1.8

—

0.2

100.0

0.0

1.1

46.9

46.0

5.1

0.7

0.2

100.0

0.1

1.0

44.4

48.4

5.1

0.7

0.3

100.0

—

1.1

49.4

43.6

5.0

0.7

0.2

100.0

—

1.2

44.5

46.2

7.0

0.7

0,4

100.0

1.0

42.5

48.7

6.8

0.5

0.5

100.0

—

1’.5

46.5

43.6

7.2

1,0

0.2

00.0

1,1

45.3

47.0

5.6

0,8

0.2

00.0

1.4

42.5

49,5

5.8

0.7

0,1

00.0

0,7

48.2

44.4

5.4

1.0

0.3

100.0

0.1

0.9

46.7

46.5

5.2

0,5

0.1

100.0

0.1

0.4

43.8

48.6

6.6

0.4

0,1

100.0

100.0

0.1

0.4

47.7

46.0

4.9

0.6

0.3

100.0

0.2

0.1

45.2

48.5

5.1

0.5

0,4

100,0

I00.0

—

1.7

47.7

46.0

3.4

0,9

0,3

I00.0

—

2,3

42.4

51.0

3.0

0.9

0.4

I00.0

100.0

—

—

1.0

49.9

44.2

4.2

0.5

0.2

100.0

—

—

0,8

50.8

44.0

3.2

1.0

0.2

100.0

t00.0

0.1

8.5

64.7

23.9

2.3

0.3

0.1

0.1

100.0

0.2

7.8

65.0

24.4

2.5

0.1

100.0

100.0

0,1

7.9

67.5

22.0

2.3

0.1

0.1

100.0

0.1

6.2

68.2

22.6

2.6

0.2

0.1

100,0

100,0

0.1

9.9

69.3

18.8

1.2

0.5

0.1

0.1

100,0

0.2

8.7

70,5

18.5

1.0

0.9

0.2

100.0

-250r less . . . . . . .

-24to-15 . . . . . . .

-14to-05, ...,..

-04to+05 . . . . . . .

+06to +15 . . . . . . .

+16to +25 . . . . . . .

+26to+35 . . . . . . .

+36 and greater . , . .

Bovs

Alllavels . . . . . .

-250r less . . . . . . .

-24to-15 . . . . . . .

-14to-05, . . . . . .

-04to+05 . . . . . . .

+06to +15 . . . . . . .

+16to +25 . . . . . . .

+26t0 +35 . . . . . . .

+36 and greater , , , .

Girls

Alllavels . . . . . .

-250r less . . . . . . .

-24to-15 . . . . . . .

-14to-05 . . . ..o.

-04to+05 . . . . . . .

+06to+15 . . . . . . .

+16to +25 . . . . . . .

+26to+35 . . . . . . .

+36 and greater . , . .

—

9.3

64.3

23.3

2.1

0.7

0.2

0.1

9.7

66.8

21.5

1.9

0.1

8.8

68,4

20.6

1.6

0,3

0,3

11.2

68.0

19.1

1.4

0.3

1.5

49.6

44.3

3.9

0.6

0.1

0.7

50.2

43.5

4.7

0,6

0.3

1.2

53.1

40.8

3.8

0.8

0,3

8.7

65.5

21.5

4.1

—

—

0.2

1.2

49.0

44.5

5.1

0,2

40
Tssble 11. Percent distribution of youths by hearing Iavels in decibels re audiometric zero (ASA-1951 and ANSI-1969) for the batter

ear at 1000 Hertz, according to age and sex: United States, 1966-70

~

Sex and hearing

levels in decibels

Both sexes

All levels . . . . . .

-250r less . . . . . . .

-24to-15 . . . . . . .

-14to-05 ..,....

-04to +05 . . . . . . .

+Q6ta +16 . . . . . . .

+16to +25 . . . . . . .

+26to +35 . . . . . . .

+36 and greater . . . .

Boys

All levels . . . . . .

-250r less . . . . . . .

-24to-15 ,., . . . .

-14to-05 . . . . . . .

-04to +05 . . . . . . .

+06to +15 ..,..,.

+16to +25 . . . . . . .

+26to +35 .,.,..,

+36 and greater , . . .

Girls

All levels . . . . . .

-260r less . . . . . . .

-24to-15 . . . . . . .

-14to-05 ...,..,

-04toio5, ..,.,.

+06to +15 . . . . . . .

+16tcr +25 . . . . . . .

+26tc) +35 . . . . . . .

+36 and greater . . . ,

Percent distribution (ASA-I 951) Percent distribution (ANSI-1969)

100.0 100.0100.0100.0 100.0

T

0.4 –

7.2 8.7

69.6 70.0

20.5 19.0

2.0 1.9

0.3 0.2

0.0 0.1

0.1

100,0 100.0

100.0

—

8.3

71.3

17.7

1.6

0.6

0.4

0.1

100.0

100.0 100.0 100.0 100.0 100.0100.0 100.0 100.0

0.1

8.6

69.0

19.6

2.0

0.5

0.2

100.0

0.1

8.6

69.0

19.5

2,0

0.5

0.2

0.1

100.0

0.2

8.7

66.8

20.8

2.5

0.8

0.1

0.1

100.0

—

9.8

66.0

20.9

2.2

0.7

0.4

0.0

100.0

8.7

71.0

18.0

1.8

0.5

100.0

—

0.2

8.7

66.7

20.8

2.5

0.8

0.3

100.0

—

9.8

66.0

20.9

2.2

0.7

0.4

100.0

0.4

7.2

69.6

20.5

2.0

0.3

0.0

100.0

—

8.7

70.0

19.0

1.9

0.2

0,2

100.0

—

8.3

71.4

17.7

1.6

0.6

0.4

[00.0

—

—

8.7

71.0

18.0

1.8

0.5

—

I00.0

0.1

8.0

58.2

20.8

1.9

0.7

0.3

0,0

100.0

0.1

9.2

69.8

18.2

2.1

0.4

0.1

0.1

0.6 -

5.9 8.2

69.1 69.3

22.2 20.2

1.5 2.0

0.6 0.1

0.1 0,2

— —

100.0 100.0

0.1 –

8.5 9.1

70.1 70,8

18.7 17.8

2.5 1.7

0.1 0.3

— —

— 0,3

—

7.4

67.5

21.8

2.1

0.7

0.3

0.2

100.0

0.5

10.0

66,0

19.7

3.0

0.8

—

9.2

84.2

23.1

2.4

0.7

0,4

—

I00.0

—

10.4

67.8

18.7

2.0

0.7

0.3

0.1

—

8.8

69.7

18.2

1.8

1.0

0s5

—

100.0

7.8

73.0

17.2

1.5

0.2

0.2

0,1

—

8.5

70.0

18.8

1.8

0.9

—

Ioo.o

—

9.0

72.1

17.1

1.8

—

—

—

0.1

8,0

68.2

20.8

1.9

0.7

0.3

100.0

0.1

9.2

69.8

18.2

2.1

0,4

0,2

—

—

7.4

67.5

21.8

2.1

0.7

0.5

100.0

—

0.5

10.0

66.0

19.7

3.0

0.8

—

—

—

9,2

64.2

23.1

2.4

0.7

0.4

I00.0

—

—

10.4

67.8

18.7

2.0

0.7

0.4

—

0.6

5.9

69.1

22.2

1.5

0.6

0.1

I 00.0

—

0.1

8.5

70.1

18.7

2.5

0.1

—

8.2

69.3

20.2

2.0

0.1

0.2

100.0

—

—

9.1

70.8

17.8

1.7

0.3

0.3

—

8.8

69.7

18.2

1.8

1.0

0.5

I00.0

—

—

7.8

73.0

17.2

1.5

0.2

0.3

—

—

8.5

70.0

18.8

1,8

0.9

—

00.0

—

9.0

72.1

17.1

1.8

—

—
Table 12. Parcant distribution of youths by haaring levels in dacibels ra audiometric zaro (ASA-1951 and ANSI-1969) for the batter

ear at 2000 Hertz, according to aga and sax: Unitad Stataa, 1966-70

Sex and hearing

levels in decibels

Both sexes Percent distribution (ASA-1951 ) Percent distribution (ANSI-1 969)

100.0 100.0

0.0 –

0.2 0.2

15.1 14,6

62.0 63.1

19.6 19.2

2.3 1.9

0.4 0.6

0.4 0.4

100,0 100.0

—

0.1 0.2

14.0 10.9

60,7 63.9

21.0 20.9

3.2 2.9

0.5 0.8

0.5 0.4

100,0 100.0

0.0 0.0

0.2 0.2

16.2 18.4

63.4 62.2

18.2 17.4

1.4 1.0

0.2 0.4

0.4 0.4

All levels . . . , . . 100.0

0.1

12.2

60.6

23.3

3.0

0.4

0.3

0.1

100.0

0.1

11.3

59.1

24.3

4.1

0.6

0.4

0.1

100.0

0.2

13.1

62.1

22.2

1.8

0.3

0.2

0.1

100.0

0.2

12.4

60.7

23.4

2.4

0.5

0.4

0.0

100.0

0.3

8.8

61.6

24.6

3.5

0.7

0.4

0.1

100.0

100.0

0.1

13.7

61.0

20,5

3.8

0.2

0.5

0.2

100.0

14.0

58.4

21,2

5.1

0.3

0.8

0.2

100.0

100.0

0.2

10.5

61.9

23.2

3.2

0.4

0.4

0.2

100.0

0.1

9.5

61.0

24.2

4.3

0.4

0.4

0.1

100.0

100.0

12,4

58.3

25.7

2.9

0.4

0.3

100.0

13.6

53.8

27.6

4,4

0.2

0.4

100.0

I00.0

0.1

11,7

62.7

21.7

3.0

0.4

0.2

0.2

100.0

12.2

61.6

21.1

3.9

0.6

0.4

0.2

100.0

100.0

0.2

12.3

59.0

25.3

2.5

0.6

0.1

100.0

100.0

—

0.1

16.8

61.0

18.1

3.1

0.2

0.7

100.0

100.0

0.3

13.8

63.5

19.1

2.6

0.2

0.5

100.0

0.1

12.2

63,5

20.1

3.3

0.3

0.5

100.0

100,0

—

0,1

14.8

59.6

22.5

2.3

0.4

0.3

100.0

—

0.1

16.2

55.4

24.3

3.4

0,3

0.3

100.0

100.0

—

0.1

15.4

62.9

18.6

2.3

0.3

0.4

100.0

100.0

.

0,1

0.2

15.2

61.9

20.2

1.8

0.5

0.1

100.0

-250r less . . . . . . .

-24to-15 . . . . . . .

-14to-05 . . . . . . .

-04to+05 . . . . . . .

+06to +15 . . . . . . .

+16to +25 . . . . . . .

+26to +35 . . . . . . .

+36 and greater . . . ,

Boys

All levels . . . . . .

0.2

9.8

58.2

27.3

3.3

1.2

100.0

-250r less . . . . . . .

-24to -15 . ..’....

-14to-05 . . . . . . .

-04to+05 . . . . . . .

+06to +15 . . . . . . .

+16to +25 . . . . . . .

+26to +35 . . . . . . .

+36 and greater . . . .

17.1

57.8

19.5

4.3

0.3

1.0

100.0

—

—

15.9

61,0

19.3

2.9

0.4

0.5

100.0

—

0.2

12.1

62.5

21.7

2.5

1.0

—

100.0

Girls

AH levels . . . . . .

-250r less . . . . . . .

-24to-15 . . . . . . .

-14to -05 . . . . . . .

-04to+05 . . . . . . .

+06to+15 . . . . . . .

+16to +25 . . . . . . .

+26to +35 . . . . . . .

+36 and greater . . . ,

0.2

16.1

59.7

22.1

1.2

0,3

0.4

0.1

13.4

63.6

19.7

2.6

0.2

0.1

0.3

0.3

11.7

62.9

22.2

2.0

r3.3

o.~

o.~

0.2

11.1

63.7

22.4

2.2

0’.-

0.1

0.2

14.7

59.e

23.2

1.7

—

0’..

0.2

0.2

18.3

61.4

18.6

1.0

0.3

11.2

63.0

23.6

1.3

0.6

0’,-

0.1

16.6

64.3

16.6

1.8

0.2

0.4

0.4

15.5

63.4

18,2

1.8

0.1

0.6

13.5

63.9

20.7

1.2

0.4

0.3

0.3

14.8

64.9

17.9

1.7

0.3

0.1

42
Table 13. Percent distribution of youths by hearing levels in decibels re audiometric zero (ASA-1951 and ANSI-1969) for the better

ear at 3000 Hartz, according to age and sex: United States, 1966-70

%x and hearing

levels in decibels

1

rotal, ,2 ,3 ,4 ,5 ,6 ,7

12-17

years years years years years years fears

Total,

12-17

years

12

years

13 14 15

years years years

16

years

17

years

II I I I I I I I

Both sexes Percent distribution (ASA-1951 ) Percent distribution (ANSI-1969)

All kNdS . . . . . .

-250r less . . . . . . .

-25to-15 . . . . . . .

-14to-05 . . . . . . .

-04to+05, . . . . . .

+06to +15 . . . . . . .

+16t04.25 . . . . . . .

+26t0 +35 . . . . . . .

+36 and greater . . . .

Boys

All levels . . , . . .

-250rless. .. m...

-24to-15 . . . . . . .

-14to-05 . . .. m..

-04to +05 . . . . . . .

+06to +15 ..,....

+16to +25 . . . . . . .

+26to +35 . . . . . . .

+36 and greater. . . . .

Girls

All levels . . . , . .

-250rlcss . . . . . . .

-25to -15...,,..

-14to -05 . . . . . . .

-04to+05 . . . . . . .

+06to +15 ..,,.,.

+16to +25 . . . . . . .

+26to +35 . . . . . . .

+36 and greater . . . .

100.0 100.0

— —

0.1 –

4.4 2.4

48,2 51.8

40.7 37.2

5.1 6.8

0.7 0.8

0.8 1.0

I00.0 100.0

—

0.2 –

2.4 2.2

43.1 44.8

46.0 42.2

6.5 8.3

1.0 1.3

0.8 1.2

I00.0 100.0

— —

—

6.4 2.7

53.4 59.0

35.2 32.1

3.7 5.2

0.5 0.3

0.8 0.7

I 00.0 100.0 I00.0 100.0100.0 I00.0 I00.0 100.0 100.0 I00.0 100.0

_

—

3.7

49.5

39.5

5.9

0.3

1.1

100.0

—

—

2.5

41.8

46,1

7.1

0.6

1.9

100.0

4.9

57.5

32.8

4.7

—

0.1

I00.0

_

—

—

3.0

49.5

42.2

4.2

0.5

0.6

I00.0

—

—

1.1

44.4

47.7

5.0

0.8

1.0

I00.0

4.9

54.7

36.6

3.4

0.1

0.3

0.0

3.1

44.8

42.8

7.5

1.0

0.5

0.3

100,0

0.1

3.2

45.0

41.4

8.0

1.3

0.5

0.5

100,0

0.1

3.9

41.8

45.7

6.6

1.0

0.7

0.2

100.0

3.6

45.1

41,7

8.1

1.0

0.4

0,1

100,0

2.2

46.6

40.7

8.5

1.0

0.6

0.4

100.0

—

3.0

45.5

42.3

7.6

0.4

0.8

0.4

100,0

—

2.3

44.7

45.0

6.3

1.1

0.4

0.2

100.0

—

0.0

3.6

49.5

39.6

5.8

0.7

0.8

100.0

—

4.1

49.2

39.2

6.3

0.7

0.5

100.0

0.1

3.8

48.8

38.8

6.5

1.0

1.0

100.0

0.0

2.0

39.2

47.3

8.9

1.3

0.8

0.5

100.0

0.1

2.3

36.8

50.3

8,1

1.3

0.8

0.3

100.0

—

2.7

41.5

44.1

9.9

1.2

0.4

0.2

100.0

—

1.5

41.8

43.7

9.9

1.7

0.6

0.8

I00.0

2.0

40.0

44.3

10.7

1.7

0.6

0.7

100.0

—

2.3

53.3

37.1

6.3

0.3

0.5

0.2

—

2.5

36.5

49.8

8.5

0.6

1.6

0.5

I00.0

—

0.9

38.0

52.2

6.1

1.8

0.8

0.2

I00.0

0.0

2.3

43.8

44.5

7.2

1.0

1.2

100.0

—

3.2

44.3

43.4

7.5

0.9

0.7

100.0

—

2.0

44.6

42.0

8.7

1.3

1.4

I 00.0

0.0

4.1

50.5

38.2

6.1

0.6

0.3

0,2

0.2

5.0

48.2

39.0

6.1

0.9

0.3

0.3

—

5.1

54.2

34.8

5.0

0.6

0.3

0.2

5.7

53.1

35.4

4.2

0.8

0.6

—

4.6

48.8

39.3

6.1

0.9

0.3

5.5

46.9

41.0

5.0

0.8

0.6

0.2

3.5

54.8

34.7

6.6

0.3

—

0.1

—

3.7

51.3

37.8

6.5

0.4

—

0.3

0.0

5.0

55.3

34.5

4.4

0.4

0.4

43
Tabla 14. Percent distribution of youths by hearing levels in decibels ra audiometric zero (ASA-’I95I and ANSI-1969) for the bettar

ear at 4000 Hartz, according to age and sex: United States, 1966-70

rotal,

I2-17

12 13 14 15 16 17

years EETETcE years years years years years years years years years years years years

Sex and hearing

levels in decibels

II I I 1 I I

Both sexes Percent distribution (ASA-1951 ) Percent distribution (ANSI-1969)

Alllevals . . . . . .

T

100.0 100.0

—.

0.8 0.5

28.7 31,5

56.2 53.6

11.4 11,5

1.3 1.7

0.6 0.7

1.0 0.5

100.0 100.0

I00.0 100.0 100.0 I00.0 I 100.0 I00.0

_

1.1

37.0

48,8

9.9

1.7

1.5

I00.0

—

0.9

34.5

47.5

11,8

2.7

2.6

100.0

1.2

39.7

50.1

8.0

0.7

0.3

100.0

_

0.1

2.2

35.4

47.9

11.3

1.4

1.7

100.0

2.4

29.4

49.5

14.2

1.5

3.0

100.0

—

0.2

1.9

41.6

46.3

8.4

1.2

0.4

100.0 I00.0 I00.0 I00.0

_

-250r less . . . . . . . 0.0

0.8

29.9

54.7

11.3

1.8

0.7

0.8

100.0

0.1

1.0

31.8

51.1

12.8

1.4

0.9

0.9

I00.0

1.0

29.6

55.0

11.1

2,5

0.4

0.4

100.0

0.5

29.8

55.8

‘10.5

1.9

0.5

1.0

I00.0

—

1.2

27.7

56.7

10,7

1.8

1.1

0.8

I00,0

0.0

1.6

34.8

50,7

9.9

1.6

1.4

100.0

—

—

1.4

34.7

51.2

9.5

2.4

0.8

100.0

0.1

1.5

33.2

52.9

9.5

1.2

1.6

I00.0

—

1.0

35.9

50.6

10.0

1.4

1.1

I00.0

—

2.3

32.4

52.8

9.0

1.6

1.9

I00.0

-24to-15 . . . . . . .

-14to-05 . . . . . . .

-04to+05 . . . . . . .

+06t0 +15 . . . . . . .

+16to +25 . . . . . . .

+26to +35 ..,....

+36 and greater . . . .

8oys

All levels , . . . . .

-250r less . . . . . . .

-24to-15 . . . . . . .

-14to-05 ..,....

-04 to +05 . . . . . . .

+06to +15 . . . . . . .

+16to+25 . . . . . . .

+26to +35 . . . . . . .

+36 and greater . . . .

,—

0.8

27.9

54.4

11.6

3.7

0.7

0.9

100.0

— —

0.5 0.5

25.4 26.5

56.8 56.9

13.0 11.9

2.5 2.4

0.3 1,2

1.5 0.6

I00.0 100.0

— _

1.2 0.5

32.2 36.8

55.6 50.2

9.6 11.0

0.1 1.0

0.9 –

0.4 0.5

—

0.3

27.3

54.4

12.3

3.0

0.8

1.9

I00.0

—

1.0

25.4

53.1

15.8

1.4

1.7

1.6

100.0

0.2

1,0

38.4

49.1

9.6

1.3

0.3

0.1

0.1

21.7

59.5

12.9

2.4

1.9

1.6

100.0

—

2.3

33.8

53.9

8.4

1.2

0.3

0.1

—

1.1

30.7

51.9

11.5

2.4

2.4

100.0

0.1

2.0

39.0

49.5

8.1

0.8

0.5

1.1

32.3

51.2

10,3

3.6

1.5

100.0

1.8

37.2

51.1

8.6

1.2

0.1

1.3

29.2

53.9

11.3

2.4

1.9

100.0

—

0.2

1.7

37.3

51.9

7.6

1.3

0.9

31.6

53.4

10,3

2.1

1.7

I00.0

—

1.1

40.3

47.7

9.7

0.7

0.5

0.1

26.9

56.0

11.5

2.1

3.4

100.0

4.4

38.1

49.7

6.4

1.0

0.4

0.6

25.7

55.8

12.9

2.6

1.1

1.3

100.0

Girls

All levels . . . . . .

-25 or less . . . . . . .

-24to-15 . . . . . . .

-14to-05 . . . . . . .

-04to +05 . . . . . . .

+06t0 +15 .,.....

+16to +25 . . . . . . .

+26to+35 .,.....

+36 and greater . . . .

0.0

1,1

34.1

53.6

9.7

1.0

0.3

0.2

1.1

31.3

55.6

10.5

1.3

0.2

0.7

32.4

57.2

8.6

0.8

0.2

0.1

44
Table 15, Persent distribution of youths by hearing levels in deaibals re audiometric zero (ASA-1951 and ANSI-1869) for the better

ear at 6000 Hertz, according to age and sex: Unitad States, 1966-70

I

Total, ,2 ,3 ,4 ,5 ,6 ,7

12-17

years”

years years years years years years

Sex and hearing

levels in decibels

II I I I I 1

Both sexes Percent distribution (ASA-I 951) Percent distribution (ANSI-1969)

All levels . . . . . . 100.0 100.0100.0 100.0 100.0 I00.0 I00.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0

-250rless . . . . . . .

-24to-15 . . . . . . .

-14to-05 . . . . . . .

-04to+05 . . . . . . .

+06to+15 . . . . . . .

+16t0 +25 . . . . . . .

+26to+35 . . . . . . .

+36 and greater . . . .

0.0

1.0

21.3

47.5

22.9

4.7

1.0

1.6

100.0

0.1

0.8

23.2

47.1

21.4

4.6

1.5

1.3

100.0

0.1

0.8

17.7

48.3

23.8

5.7

1.3

2.3

I00.0

0.0

0.0

1.4

24.1

47.7

20.1

4.1

2.6

I00.0

0.1

—

1.3

21.0

48.1

21.4

4.5

3.6

100.0

1.3

25.0

48.8

18.0

4.6

1.0

1.3

100.0

1.2

21.6

46.0

25.4

3.4

0.8

1.6

I00.0

0.8

20.1

47.5

24.4

4.7

0.9

1.6

100.0

—

0.9

19.4

47.6

24.6

5.1

0.7

1.7

I00.0

—

—

1.8

27.5

49.0

15.2

4.4

2.1

100.0

0.1

1.0

27.1

45.4

20.0

3.6

2.8

100.0

—

1.8

24.6

46.8

21.2

3.2

2.4

100.0

—

—

1.0

22.9

48.1

21.1

4.5

2.4

I 00.0

1.7

20.8

49.1

21.8

4.2

2.4

100.0

80VS

All levels . . . . . .

-250rless . . . . . . .

-24to -15 . . . . . . .

=14to-05. .m . . . .

-04to+05 . . . . . . .

i-06to+15 . . . . . . .

+16to+25 . . . . . . .

+26to+35 . . .. m..

+36 and greater . . . .

0.()

0.5

18.1

45.9

25.8

5.8

1.3’

2.6

100.0

0.1

0.4

14.4

44.8

28.6

6.0

1.4

4.3

00.0

—

1.1

21.1

51.8

19.0

5.5

1.2

0.3

0.0

0.7

21.1

46.4

22.8

5.1

3.9

I00.0

0.1

1.0

17.3

45.4

25.9

4.6

5.7

100.0

1.6

24.8

50.9

16.9

4.3

1.5

0.8

23.4

47.5

19.1

5.8

1.2

2.2

I00.0

0.7

20.1

47.2

22.7

5.6

1.8

1.9

i 00.0

0.4

18.4

45.6

27.9

4.4

1.2

2.1

00.0

0.6

16.6

47.6

25.6

6.2

1.0

2.4

100.0

—

1.2

23.7

47.4

23.1

3.2

0.7

0.7

—

15.1

42.1

32.0

6.8

0.9

3.1

00.0

1.8

23.8

53.2

17.1

3.3

0.5

0.3

—

0.9

26.3

47.6

16.1

5.7

3.4

I00.0

—

2.6

28.8

50.5

14.2

3.2

0.7

—

0.7

23.8

45.8

21.4

4.6

3.7

100.0

—

0.2

1.2

30.6

45.0

18.6

2.6

1.8

—

0.7

21.8

47.4

22.8

4.1

3.2

I00.0

—

0.6

20.0

47.4

23.0

5.7

3.3

I00.0

—

—

1.6

25.8

48.9

19.1

3.2

1.4

0.5

16.5

44.7

28.5

5.9

3.9

I00.0

Girls

All levels . . . . . .

-250rless . . . . . . .

-24to-15 . . . . . . .

-14to-05 ..,....

-04to+05 . . . . . . .

+08to +15 . . . . . . .

+16to+25 .,.....

+26to +35 . . . . . . .

+36 and greater . . . .

0.0

1.5

24.5

49.3

19.8

3.5

0.8

0.6

0.2

0.9

26.4

47.0

20.1

3.6

1.2

0.6

1.8

26.7

50.1

17.0

3.3

0.8

0.3

—

2.1

24.8

46.5

22.8

2.3

0.4

1.1

—

0.0

2.2

27.2

49.0

17.3

3.0

1.3

—

2.9

27.5

46.1

19.7

2.3

1.5

3.0

25.2

53.5

15.0

2.4

0.9

45
Table 16. Percent distribution of youths by hearing levels in decibels re audiometric zero (ASA-1951 and ANSI-1969) for the better

ear at 8000 Hertz, according to age and sex: United States, 1866-70

rotal, ,2 ,3 ,4 ,5 ,6 ,7

I 2-17

fears years years years years years years

Sex and hearing

levels in decibels

Both sexes Percent distribution (ASA-1 951) Percent distribution (ANSI-1969)

All levels . . , . . . I00.0 100.0 100.0 I00.0 I00.0 I00.0

_

1.7

19.5

45.2

26.9

4.4

1.1

0.3

0.9

I00.0

I00.0

_

1.3

19.1

47.3

25.4

4.2

1.7

0.2

0.8

100.0

100.0

_

0.0

0.2

7.3

38.8

39.2

10.6

2.3

1.6

100.0

100.0

_

—

0.1

7.3

37.1

41.0

10.6

2.5

1.4

100.0

I00.0

_

0.1

6.7

37.2

39.6

12.4

2.4

1.6

100.0

100.0

0.1

0.3

7.1

37.9

41.3

9.3

2.7

1.3

100.0

I00.0

0.1

7.7

40.1

35.7

12.5

1.8

2.1

I 00.0

00.0

.

—

0.6

8.3

40.2

38.0

9.4

1.9

1.6

100.0

I00.0

_

0.1

6.7

40.8

39.5

9.1

2.3

1.5

100.0

-250r less . . . . . . .

-24to-15 . . . . . . .

-14 to-05 . . . . . . .

-04to+05 . . . . . . .

+06tlJ +15 . . . . . . .

+16tr) +25 . . . . . . .

+26tO+35 . . . . . . .

+36 and greater . . . .

1.0

18.1

47.0

26.3

5.1

1.2

0.5

0.8

100.0

0.6

16.2

48.9

28.0

5.8

1.3

0.4

0.8

100.0

0.4

17.1

47.6

27.1

5.5

1.2

0.4

0.7

I00.0

1.5

17.6

47.4

26.3

5.4

0.6

0.5

0.7

100.0

0.4

19.3

45.7

26.2

5.2

1.4

1.1

0.7

I00.0

Boys

AH levels . . . . . .

0.3

19.4

42.8

27.0

6.3

2.0

1.3

0.9

100.0

1.0

16.4

45.0

29.6

4.4

1.5

0.6

1.5

I 00.0

2.1

16.2

48.6

23.8

4.8

2.9

0.3

1.3

100.0

0.0

0.1

6.8

37.5

39.0

11.2

3.1

2.3

100.0

0.2

0,3

5.3

37.9

42.3

9.5

3.2

1.3

100.0

-250r less . . . . . . .

-24to-15 . . . . . . .

-14to-05 . . . . . . .

-04to+05 . . . . . . .

+06to +15 . . . . . . .

+16trj+25 . . . . . . .

+26to+35 . . . . . . .

+36 and greater . . . .

0.9

17.1

45.6

27.1

5.8

1.8

0.6

1.1

100.0

0.7

17.7

44.3

26.5

7.4

1.8

0.4

1.2

100.0

0,2

15.9

46.6

27.4

6.3

2.0

0.4

1.2

I00.0

1.1

16.8

46.7

28.0

5.6

0.6

0.5

0.7

100.0

—

0.1

7.0

35.7

38.8

13.2

3.4

1.8

100.0

—

7.3

35.0

39.6

12.9

2.8

2.4

I00.0

—

8.4

36.7

36.6

12.6

2.9

2.8

100.0

0.3

6.4

39.6

38.3

10.3

2.1

3.0

I00,0

0.9

10.3

40.8

37.6

8.4

1.7

0.3

0.2

6.2

40.4

38.5

8.5

3.B

2.4

100.0

7.2

41.2

40.6

9.6

0,7

0.7

Girls —

All levels . . . . . .

-250riess . . . . . . . 1.1

19.1

48.5

25.5

4.4

0.6

0.4

0.4

0.6

14.7

53.6

25.6

4.1

0.8

0.3

0.3

0.6

18.2

48.7

26.7

4.7

0.5

0.3

0.3

1.8

18.4

48.1

24.5

5.2

0.7

0.6

0.7

0.6

19.3

48.6

25.4

4.2

0.7

0.8

0.4

2.5

22.7

45.4

24.0

4.5

0.6

—

0.3

0.5

22.1

45.9

27.0

3.6

0.6

0.3

0.3

7.9

40.2

39.4

9.9

1.4

0.9

—

—

7.7

38.6

43.2

8.0

1.5

1.0

—

0.3

6.0

39.4

39.7

11.9

1.9

0.8

—

0.4

9.0

37.9

40.3

9.0

2.1

1.3

0.3

7.0

43.6

34.8

12.3

0.6

1.4

-24to-15 . . . . . . .

-14to-05 . . . . . . .

-04to+05 . . . . . . .

+rMto +15 . . . . . . .

+16to+25 . . . . . . .

+26to +35 . . . . . . .

+36 and greater . . . .

46
Table 17. Median hearing levels in decibels re audiometric zero (ASA-1951 and ANSI-1969) for the right, left, and better ear of youths

12-17 years at each test frequency and estimates for speech, by age: United States, 1866-70

Ear and tonal frequent}

Right ear

250 Hertz . . . . . . . .

500 Hertz . . . . . . . .

1000 Hertz, . . . . . . .

2000 Hertz . . . . . . . .

3000 Hertz . . . . . . . .

4000 Hertz ..,.....

6000 Hertz . . . . . . . .

8000 Hertz . . . . . . . .

Speech’ . . . . . . . . .

Left ear

250 Hertz . . . . . . . .

500 Hertz . . . . . . . .

1000 Hertz . . . . . . . .

2000 Hertz . . . . . . . .

3000 Hertz . . . . . . . .

4000 Hertz . . . . . . . .

6000 Hertz . . . . . . . .

f3000 Hertz . . . . . . . .

Speech. . . . . . . . .

Better ear

250 Hertz . . . . . . . .

500 Hertz, ...,...

1000 Hertz . . . . . . . .

2000 Hertz . . . . . . . .

3000 Hertz . . . . . . . .

4000 Hertz . . . . . . . .

6000 Hertz ..,.....

8000 Hertz . . . . . . .. .

Speech’ . . . . . . . . . .

Total,

12-17 ‘2 ‘3 14 15 16 17

years

years years years years years years

Hearing levels (ASA-I 951)

-9.3

-7.8

-7.9

-7.3

-2.3

0.0

3.1

-5.7

-6.6

-8.3

-7.5

-7.4

-6.6

-1.6

1,3

4.7

-5.2

-5.8

-10.1

-8.9

-9.0

-8.8

4.5

-1.5

0,8

-8.4

-7.7

-9.1

-7.6

-7.4

-7.4

-2.3

0.0

2.2

-5.7

-6.4

-8.5

-7.2

-7.2

-6.7

-1.8

1.1

3.4

-4.3

-5.6

10.1

-8.6

-8.8

-8.8

-4.7

-1.5

-0.1

-8.2

-7.6

-9.0

-7.4

-7.8

-7.7

-2.3

0.2

2.7

-5.7

-6.5

-8.1

-7.1

-7.2

-6.8

-1.4

1.3

4.6

-4.7

-5.5

-10.0

-8.6

-8.9

-9,1

4.6

-1.4

0.5

-8.2

-7.6

-9.4

-7.6

-7.7

-7.2

-2.0

0.0

3.1

-5.3

-6.5

-8.6

-7.3

-7.5

-6.7

-1.5

1.2

4.4

-5.6

-5.7

-10.3

-8.8

-8.9

-8.7

-4.1

-1.6

0.9

-8,5

-7.6

-9.3

-7.5

-8.0

-6.9

-2.4

0.0

3.5

-5.5

-6.2

-8.2

-7.5

-7.5

-6.2

-1.5

1.4

5.2

-5.4

-5.7

-10.2

-8.8

-9.1

-8.6

-4.7

-1.5

1.1

-8.4

-7.4

-9.5

-8.2

-8.2

-7.5

-2.6

0.0

4.1

-6.0

-7.0

-8.2

-8.0

-7.6

-6.8

-1.8

1.2

5.4

-5.8

-6.1

-10.2

-9.2

-9.2

-8.9

-4.6

-1.6

1.5

-8.6

-8.0

-9.2

-8.4

-8.2

-7.1

_2j

O.c

3.3

-6.1

-6.8

-8.0

-7.6

-7.5

-6.7

-1.8

1.5

5.4

-5.5

-6.3

-10.0

-9.3

-9.2

-8.6

4.3

-1.3

1.2

-8.7

-7.8

Total, ,2 ,3 ,4 ,5 ,6 ,7

12-17

years years yews years years years

years

11 , , , ,

i-fearinglevels (ANSI-I 969)

10.1

7’.-

2.1

2.C

6.E

9.3

12.3

8.9

5.7

11.1

7.8

2.6

2.5

7.6

10.6

13.6

9.2

6.5

9.2

5.4

1.0

0.6

4.4

7.7

10.1

5.9

4.0

10.3

7.7

2.6

1.9

6.9

9.3

11.5

8.8

6.2

10.9

8.0

2.8

2.5

7.4

10.5

12.4

9.8

6.7

9.2

5.9

1.2

0.6

4.3

7.7

9.2

6.3

4.5

10.4

7.5

2.2

1.8

6.9

9.6

12.0

9.2

5.4

11.3

8.2

2.8

2.6

7.8

10.8

13.8

10.0

9.9

7.4

2.3

2.0

6.8

9.1

12.3

9.0

6.0

10.7

7.9

2.5

2.5

7.6

10.5

13.1

9.2

6.8 6.5

9.5 9,0

5.8 5.5

1.1 1.1

0.4 0.7

4.5 4.4

7.9 7.6

9.8 10.1

6.5 6.1

4.0 4.1

10.0 9.9

7.4 7.2

2.0 1.8

2.3 1.8

6.7 6.6

9.2 9.2

12.7 13.4

9.2 8.5

6.2 5.3

11.2 11.4

7.8 7.3

2.5 2.4

3.0 2.4

7.7 7.5

10.6 10.7

14.2 14.4

9.1 8.2

6.6 6.1

9.0 9.2

5.4 5.1

0.9 0.8

0.9 0.5

4.2 4.4

7.4 7.6

10.4 10.7

5.6 5.3

4.3 3.4

10.1

6.4

1.8

2.1

6.8

9.3

12.5

8.8

5.1

11.4

7.4

2.5

2.3

7.4

10.8

14.4

8.9

6.4

9.4

4.8

0.8

0.6

4.5

7.9

10.6

5.6

3.7

1A“erag@of lavals at 500, 1000. and Zooo Hertz.
Table 18. Median haaring Iwels in decibels re audiometric zero (ASA-1 951 and ANSI-1869) for the right, Ieft, and better eer of boys

12-17 years at each test f requency and estimatesfor speech, by age: United States, 1966-70

Ear and tonal frequency

Right ear

250 Hertz . . . . . . . .

500 Hertz . . . . . . . .

1000 Hertz . . . . . . . .

2000 Hertz . . . . . . . .

3000 Hertz . . . . . . . .

4000 Hertz . . . . . . . .

6000 Hertz . . . . . . . .

8000 Hertz . . . . . . . .

Speech’ . . . . . . . . . .

Left ear

250 Hertz . . . . . . . .

500 Hertz . . . . . . . .

1000 Hertz . . . . . . . .

2000 Hertz . . . . . . . .

3000 Hertz . . . . . . . .

4000 Hertz . . . . . . . .

6000 Hertz . . . . . . . .

8000 Hertz . . . . . . . .

Speech’ . . . . . . . . . .

Better ear

250 Hertz . . . . . . . .

500 Hertz . . . . . . . .

1000 Hertz . . . . . . . .

2000 Hertz . . . . . . . .

3000 Hertz . . . . . . . .

4000 Hertz . . . . . . . .

6000 Hertz . . . . . . . .

8000 Hertz . . . . . . . .

Speech’ . . . . . . . . .

Hearing levels (ASA-I 951)

-9.3

-7.6

-7.8

-7.1

-1.4

0.6

4,6

-4.9

-6.3

-8.3

-7.2

-7.1

-6.1

-0.5

2.3

6.3

-4.3

-5.2

-10.1

-8.7

-8.9

-8.5

-3.1

-0.8

1.8

-8.0

-7.4

-9.5

-7.7

-7.4

-7.1

-1.8

0.2

2.7

“-4.8

-6.2

-8.7

-6.7

-6.8

-6.1

-0.8

1.9

4.7

-3.3

-5.1

-10.4

-8.5

-8.7

-8.3

-3.7

-1.1

0.4

-7.9

-7.5

-9.1

-7.4

-7.7

-7.7

-1.3

0.7

3,8

-4.9

-6.3

-8.3

-7.0

-6.8

-6.3

-0.4

2.0

5.7

-3.8

-5.0

-10.1

_8m5

-8.C

-8..5

-3.~

-0.7

1.5

-7.7

-7.:

-9.4

-7.3

-7.5

-7.0

-1.2

0.5

4.4

-4.6

-6.1

-8.6

-6.9

-7.2

-6.0

-0.3

1.9

5.7

-4.7

-4.8

-10.3

-8.6

-8.7

-8.4

-2.8

Jj.g

1.E

-8.1

-7.2

-9.3

-7.3

-7.9

-6.6

-1.6

0.5

4.7

-4.5

-6.0

-8.1

-7.3

-7.1

-5.5

-0.3

2.3

6.6

-4.5

-4.9

-10.2

-8.6

-9.0

-8.2

-3.2

-0.9

1.9

-7.9

-7.1

-9.3

-7.9

-8.1

-7.6

-1.4

0.7

6.6

-5.1

-6.9

-8.3

-7.8

-7.6

-6.5

-0.3

2.5

6.9

-4.5

-5.8

-10.1

-9.2

-9.1

-8.9

-2.8

-0.6

2.8

-7.7

-8.0

17

tears

-9.0

-8.4

-8.1

-6.6

-1.3

1.0

6.1

-5.4

-6.4

-7.9

-7.3

-7.0

-5.9

-0.6

3.1

8.4

-5.0

-5.6

-9.8

-9.2

-9.1

-8.1

-2.9

-0.3

3.3

-8.5

-7.4

Hearing levels (ANSI-1 969)

10.1

7.6

2.2

2.2

7.8

9.9

13.6

9.5

6.1

11.1

8.1

2.9

3.1

8.9

11.6

15.0

10.0

7.1

9.2

5.9

1.1

().g

5,~

8.5

11.1

6.4

4.4

10.0

8.0

2.6

2.3

7.6

9.6

11.9

9.3

6.6

10.7

8.3

3.2

3.1

8.5

11.3

13.7

10.8

7.0

9.0

6.4

1.3

1.1

5.6

8.3

9.8

6.9

4.8

10.4

7.7

2.3

1.9

8.0

10.2

13.0

9.7

5.6

11.2

8.6

3.2

3.1

9.0

11.4

14.9

10.5

7.6

9.4

6.2

1.4

0.7

5.8

8.6

10.6

6.9

4.6

9.9

7.9

2.5

2.1

7.9

9.6

13.4

9.6

6.4

10.6

8.3

2.8

3.1

9.0

11.3

13.9

9.8

7.4

8.9

6.2

1.3

0.9

5.9

8.3

10.8

6.5

4.6

10.1

7.6

2.1

2.5

7.8

9.8

14.0

9.8

6.2

11.3

8.2

2.9

3.6

9.0

11.5

15.6

10.1

7.2

9.1

5.9

1.0

1.1

5.7

8.1

11.2

6.4

4.5

10.1

7.6

1.9

1.7

7.8

10.0

15.5

9.3

5.9

11.3

7.8

2.4

2.7

9.1

11.9

15.7

9.2

6,2

9.3

6.C

0.$

0.6

6’.-

8.7

12,C

6.C

3.7

17

,ears

10.4

6.3

1.9

2.5

7.9

10.4

14.8

9.1

5.5

11.6

7.4

3.0

2.8

8,6

12.2

17.2

9.6

6.9

9.6

4.7

0.9

1.0

5.9

9.1

12.4

5.8

4.1

1Average of [evelsat 500, 1000, and 2000 Hertz.

48
Table 19. Median hearing levels in decibels re audiometric zero (ASA-1951 and ANSI-1869) for the right, left, and batter ear of @

12-17 yaars at each test frequency and estimatesfor speech, by age: United Statas, 1866-70

Ear and tonal frequent)

N$!!K2Y

250 Hertz . . . . . . . .

500 Hertz . . . . . . . .

1000 Hertz, ,, . . . . .

2000 Hertz . . . . . . . .

3000 Hertz . . . . . . . .

4000 Hertz . . . . . . . .

6000 Hertz . . . . . . . .

8000 Hertz . . . . . . . .

Speech. . . . . . . . . .

Left ear

250 Hertz .,......

500 Hertz, . . . . . . .

1000 Hertz . . . . . . . .

2000 Hertz . . . . . . . .

3000 Hertz . . . . . . . .

4000 Hertz, .,.....

6000 Hertz, ...,..,

8000 Hertz . . . . . . . .

Speech’ ...,...,,.

Better ear

250 Hertz . . . . . . . .

500 Hertz . . . . . . . .

1000 Hertz . . . . . . . .

2000 Hertz . . . . . . . .

3000 Hertz . . . . . . . .

4000 Hertz .,....,,

6000 Hertz . . . . . . . .

8000 Hertz . . . . . . . .

Spaechl . . . . . . . . .

Total, Totel, ,2 ,3 ,4 ,5 ,6 ,7

12-17 ‘2 ‘3 ‘4 ‘5 ‘6 ‘7 12-17

years ‘ears ‘aars ‘ears ‘ears ‘ears ‘ears yeers

years years years years years years

-9.3

-7.9

-8.0

-7.5

-3.3

-0.6

1.9

-6.4

-6.8

-8.2

-7.8

-7.7

-7.2

-2.9

0.4

3.3

-6.0

-6.4

-10.1

-9.0

-9.2

-9,1

-5.9

-2.2

-0.1

-8.9

-7.9

-8.7

-7.5

-7.5

-7.8

-2.8

-0.2

1.8

-6.4

-6.7

-8.2

-7.6

-7.6

-7.3

-2.9

0.4

2,2

-5.2

-6.0

-9.8

-8.7

-9.0

-9.4

-5.7

-1.8

-0.7

-8.5

-7.8

Hearing levels (ASA-1951 )

-8.9

-7.5

-7.9

-7.7

-3.5

-0.4

1.6

-6.4

-6.8

-8.0

-7.3

-7.6

-7.2

-2.5

0.8

3.7

-5.6

-6.0

-9.9

-8.7

-9.2

-9.3

-5.7

-2.0

-0.2

-8.6

-7.9

-9.4

-7.9

-7.9

-7.4

-2.9

-0.6

2.0

-5.9

-6.8

-8.5

-7.5

-7.7

-7.4

-2.9

0.5

3.3

-6.4

-6.4

-10.3

-9.0

-9.1

-8.9

-5.5

-2.5

0.0

-8.8

-7.8

-9,3

-7.6

-8.o

-7.1

-3.1

-0.6

2.4

-6.3

-6.3

-8.3

-7.8

-7.9

-6.8

-2.9

0.5

4.0

-6.1

-6.5

-10.3

-9.0

-9.2

-8.8

-6.0

-2.0

0.3

-8.8

-7.8

-9.7

-8.6

-8.3

-7.3

-3.8

-0.7

2.2

-6.9

-7.1

-8.1

-8.3

-7.6

-7.0

-3.5

-0.1

4.2

-6.9

-6.4

-10.2

-9.3

-9.2

-8.9

-6.5

-2.9

0.4

-9.5

-8.1

-9.7 10.1

-8.4 7.0

-8.2 2.0

-7.6 1.8

-3.7 5.5

-1.0 8.7

1.4 11.2

-6.8 8.4

-7.1 5.4

-8.2 11.2

-7.9 7.4

-7.9 2.3

-7.4 2.0

-3.1 6.1

0.0 9.7

2.9 12.4

-6.1 8.5

-6.8 5.9

-10.1 9.2

-9.3 4.9

-9.3 0.8

-8.1 0.3

-6.0 3.1

-2.4 6.8

-0.4 9.2

-9.0 5.4

-8.2 3.6

Hearing levels (ANSI-1969)

10.6

7.4

2.5

1.5

6.1

9.0

11.1

8.4

5.7

11.0

7.6

2.4

2.0

6.2

9.7

11.3

8.9

6.4

9.5

5.5

1.0

0.1

3.3

7.2

8.7

5.8

4.2

10.5

7.3

2.1

1.7

5.0

8.8

11.1

8.7

5.1

11.5

7,7

2.4

2.1

6.5

10.1

12.8

9.5

5.9

9.5

5.3

0.8

0.2

3.3

7.1

9.0

6.1

3.4

10.0

6.8

2.1

1.8

5.4

8.6

11.3

8.3

5.6

10.8

7.4

2.3

1.9

6.0

9.7

12.3

8.6

5.4

9.0

4.8

0.9

0.4

3.2

6.8

9.3

5.7

3.6

10.0

7.3

2.0

2.1

5.6

8.7

11.5

8.6

6.1

11.1

7.3

2.1

2.5

6.2

9.8

12.9

8.0

6.0

8.9

4.8

0.8

0.7

3.0

6.8

9.6

4.8

4.0

9.8

6.7

1.7

1.9

5.0

8.5

11.7

7.7

4.8

11.5

6.7

2.4

2.0

5.7

9.5

13.3

7.2

5.8

9.1

4.2

0.8

0.4

2.9

6.4

9.6

4.5

3.2

9.7

6.6

1.8

1.7

5.4

8.2

10.7

8.5

4.8

11.2

7.4

2.1

1.8

6.0

9.4

12.2

8.1

5.8

9.2

5.0

0.7

0.1

3.2

6.5

9.1

5.4

3.3

1Av~refl~ of levelsat 500, 1000, and 2ooo Hertz.

49
Table 20. Medians and quartile points’ in tha distribution of hearing Ievals in decibels ra audiometric zaro (ANSI-19691 for the

better ear at each test frequency and estimates for s-h among whita youths, by age and sex: United States, 1966-70

250 Hertz 500 Hertz 1000 Hartz

I I I I I I I I

Age and sex

’25 Median P75 I

P~~ Median P75 I

P25 Median P76

Both sexes Decibels re audiometric zero (ANSI-1969)

12-17 years . . . . . . . . . . . . . . .

12years . . . . . . . . . . . . . . . . . . .

13years . . . . . . . . . . . . . . . . . . .

14years . . . . . . . . . . . . . . . . . . .

15years . . . . . . . . . . . . . . . . . . .

16years . . . . . . . . . . . . . . . . . . .

17 years . . . . . . . . . . . . . . . . . . .

Boys

12-17 years . . . . . . . . . . . . . . .

12years . . . . . . . . . . . . . . . . . . .

13years . . . . . . . . . . . . . . . . . . .

14years . . . . . . . . . . . . . . . . . . .

15yaers . . . . . . . . . . . . . . . . . . .

16years . . . . . . . . . . . . . . . . . . .

17years . . . . . . . . . . . . . . . . . . .

Girls

12-17years . . . . . . . . . . . . . . .

12years . . . . . . . . . . . . . . . . . . .

13years . . . . . . . . . . . . . . . . . . .

14years . . . . . . . . . . . . . . . . . . .

15years . . . . . . . . . . . . . . . . . . .

16years . . . . . . . . . . . . . . . . . . .

17years . . . . . . . . . . . . . . . . . . .

See footnotes at end of table.

5.3 9.3 13.3 0.2 5.5 10,9 -2.7 0.9 4.5

5.2

5.7

4.9

5.0

5.5

5.5

5.5

5.0

6.0

5.3

5.3

5.7

5.9

5.1

5.4

5.3

4.2

4.2

5.2

5.1

9.3

9.6

8.9

9.1

9.3

9.4

9.4

9.1

9.7

9.0

9.4

9.4

9.8

9.2

9.5

9.6

8.9

8.9

9.2

9.1

13.4

13.6

12.9

13.3

13.1

13.3

13.3

13.2

13.5

12.7

13.5

13.1

13.6

13.3

13.6

13.8

13.2

13.1

13.1

13.1

0.3

0.4

0.2

0.3

-0.1

-0.2

0.6

5.9

6.0

5.5

5.7

5.3

4.8

6.2

11.3

11.1

10.8

10.9

10.6

10.5

11.2

-2.6

-2.8

-2.5

-2.7

-2.7

-2.8

-2.5

1.1

1.0

1.0

0.8

0.8

0.8

1.1

4.8

4.7

4.6

4.3

4.3

4.3

4.8

-2.4

-2.6

-2.3

-2.6

-2.7

-2.7

-2.8

1.3

1.3

1.2

1.0

0.9

0.9

0.7

5.0

!5.4

4.8

4.5

4.!5

4.5

4.3

0.5

0.8

0.6

0.9

0.6

0.0

-0.2

0.1

0.0

-0.3

-0.2

-0.6

-0.3

6.2

6.6

6.2

6.4

6.3

5.1

4.8

5.5

5.2

4.8

4.7

4.1

4.6

11.4

11.4

11.3

11.3

11.1

10.6

10.5

11.3

10.8

10.3

10.4

9.9

10.4

-2.8

-2.9

-2.7

-2.9

-2.7

-2.8

0.9

0.7

0.8

0.6

0.7

0.6

4.6

4.3

4.4

4.0

4.1

4.1

50
Table 20. Mediens and quartile points’ in the distribution of hearing Iavels in decibels re audiometric zero (ANSI-1969) for the

better earateach tetifrequency andestimates forspeech among white youthsr byage and sex: United States, 1966-70–Con.

Age and sex

Both sexes

12-17 years . . . . . . . . . . . . . . .

12years . . . . . . . . . . . . . . . . . . .

13years . . . . . . . . . . . . . . . . . . .

14yeers . . . . . . . . . . . . . . . . . . .

15years, . . . . . . . . . . . . . . . . . .

16years . . . . . . . . . . . . . . . . . . .

17years . . . . . . . . . . . . . . . . . . .

Boys

12-17years . . . . . . . . . . . . . . .

12 years . . . . . . . . . . . . . . . . . . .

13years . . . . . . . . . . . . . . . . . . .

14years, . . . . . . . . . . . . . . . . . .

,15years . . . . . . . . . . . . . . . . . . .

16years . . . . . . . . . . . . . . . . . . .

17 years . . . . . . . . . . . . . . . . . . .

Girls

12-17 years . . . . . . . . . . . . . . .

12years . . . . . . . . . . . . . . . . . . .

13years . . . . . . . . . . . . . . . . . . .

14years . . . . . . . . . . . . . . . . . . .

15years .. m........,.. . . . . .

16years . . . . . . . . . . . . . . . . . . .

17years . . . . . . . . . . . . . . . . . . .

See footnotes at end of table.

—

2000 Hertz 3000Hertz 4000 Hertz

’25 Median P75 P25 Median P75 P25 Median P75

Decibels re audiometric zero (ANSI-1969)

-3.5

-3.5

-3.7

-3.3

-3.4

-3.6

-3.7

-3.3

-2.9

-3.7

-3.1

-3.4

-3.6

-3.1

-3.7

4.2

-3.7

-3.5

-3.4

-3.6

-4.2

0.5

0.4

0.3

0.6

0.8

0.3

0.4

0.8

1.0

0.5

0.8

1.0

0.4

1.0

0.1

-0.2

0.0

0.3

0.5

0.3

-0.2

4.4

4.4

4.2

4.4

4.9

4.3

4.5

4.9

4.9

4.8

4.7

6.0

4.5

5.4

4.0

3.8

3.7

4.2

4.5

4.1

3.9

-0.9

-1.0

-0.9

-1.0

-0.7

-0.8

-0.7

0.0

-0.4

0.1

0.0

0.0

0.1

0.2

-1.6

-1.5

-1.7

-1.8

-1.3

-1.6

-1.5

4.0

3.9

3.9

4.1

4.0

4.1

4.2

5.5

5.0

5.5

5.6

5.6

5.9

5.7

2.8

2.9

2.6

2.8

2.8

2.7

3.0

10.2

10.2

10.3

10.2

10.3

10.3

10.1

11.3

11.1

11.5

11.2

11.6

11.6

11.1

8.7

9.0

8.6

8.8

8.5

8.6

8.8

1.5

1.5

1.9

1.4

1.4

1.2

1.6

2.6

2.1

3.0

2.4

2.0

2.4

4.2

0.6

1.0

0.9

0.6

0.9

0.3

-0.1

7.5

7.5

7.7

7.3

7.3

7.4

7.7

8.4

8.1

8.6

8.2

8.0

8.6

9.1

6.5

6.9

6.8

6.4

6.6

6.0

5.9

12.5

12.5

12.5

12.4

12.4

12.8

12.5

13.3

13.1

13.2

12.9

13.2

13.8

13.7

11.6

11.8

11.6

11.7

11.6

11.6

11.1

51
Table 20. Madians and quartile points’ in tha distribution of hearing levels in decibels re audiometric zero (ANSI-1969) for the

better ear at each test frequancy and estimates for speech among white youths, by age and sex: United States, 1966-70-Con.

Age and sex

6000 Hertz 8000 Hertz I Speech2

’25 Median P75 ’25 Median P75 ’25 Median P75

Both sexes Decibels re audiometric zero (ANSI-1969)

12-17 years . . . . . . . . . . . . . . . 5.0 10.3 16.2 -0.4 6.1 12.4 -0.6 3.9 9.6

-

12years . . . . . . . . . . . . . . . . . . .

13 years . . . . . . . . . . . . . . . . . . .

14years . . . . . . . . . . . . . . . . . . .

15years . . . . . . . . . . . . . . . . . . .

16years . . . . . . . . . . . . . . . . . . .

17years . . . . . . . . . . . . . . . . . . .

3.5

4.3

4.5

5.4

5.7

5.6

5.9

9.3

10.1

10.2

10.5

11.0

10.7

11.4

14.4

16.3

16.3

16.4

17.7

17.0

18.6

-0.1

-0.1

-0.3

-0.7

-0.9

-0.4

0.0

6.5

6.6

6.3

5.6

5.5

5.9

6.7

12.6

13.0

12.2

12.6

12.0

12.1

13.0

-0.4

-0.6

-0.6

-0.4

-0.8

-0.8

4.3

3.8

3.9

4.3

3.4

3.5

10.1

9.7

9.7

9.9

9.2

9.2

10.1

Boys

12-17years . . . . . . . . . . . . . . . -0.4 4.4

4.4

5,7

5.7

6.0

6.7

6.9

3.5

10.0

11.0

11.1

11.3

12.3

12.8

9.2

16.2

17.9

17.9

18.3

19.9

20.3

14.3

0.2

9.3

0.3

-0.3

-0.2

-0.3

-0.8

7.2

7.4

6.8

6.3

6.4

6.1

5.4

13.6

13.5

12.6

13.1

12.8

12.5

11.8

-0.2

-0.2

-0.4

-0.2

-0.6

4.7

4.6

4.3

4.7

3.9

10.4

10.4

9.9

10.3

9.7

9.8

9.1

12years . . . . . . . . . . . . . . . . . . .

13years . . . . . . . . . . . . . . . . . . .

14years . . . . . . . . . . . . . . . . . . .

15years . . . . . . . . . . . . . . . . . .

16years . . . . . . . . . . . . . . . . . . .

17years . . . . . . . . . . . . . . . . . . . . -0.5

-0.8

4.1

3.4

Girls

12-17 years . . . . . . . . . . . . . . .

T

-0.6 3.9

-1.0 3.1

-0.7 3.6

-0.6 3.9

-1.0 3.0

-1.1 3.0

8.6

9.1

9.2

9.7

9.8

9.1

13.4

14.7

14.6

14,6

14.8

13.6

-0.4

-0.5

-0.9

-1.0

-1.7

-0.6

5.9

5.8

5.6

4.9

4.6

5.7

11.7

12.4

11.8

12.1

11.1

11.7

9.6

8.7

9.3

9.5

8.6

8.6

12years . . . . . . . . . . . . . . . . . . .

13years . . . . . . . . . . . . . . . . . . .

14years . . . . . . . . . . . . . . . . . . .

15years . . . . . . . . . . . . . . . . . . .

16years . . . . . . . . . . . . . . . . . . .

17years . . . . . . . . . . . . . . . . . . .

2.8

2.8

2.9

4.5

4.7

3.9

‘1’25,m edian, and P75 are the points in the distribution of hearing levels below which 25, 50, and 75 percent of tha children, respectively fall.

2Averege of hearing levels at 500, 1000, and 2ooo Hertz.

.

52
Table 21. Medians rmdquartilepointsl inthedi~ribution ofheering levels indecibels reaudiometric zero (ANSl-1969) forthektier

earataach t@ frequency end~timates forspewh among -youths, byageandwx: United States, 1966-70

250 Hertz 500 Hertz 1000 Hertz

’25 Median P75 ’25 Median P75 ’25 Median P75

Age and sex

Both sexes Decibels re audiometric zero (ANSI-I 969)

12-17 years . . . . . . . . . . . . . . .

12years . . . . . . . . . . . . . . . . . . .

13years . . . . . . . . . . . . . . . . . . .

14years . . . . . . . . . . . . . . . . . . .

15years . . . . . . . . . . . . . . . . . . .

16years . . . . . . . . . . . . . . . . . . .

17years . . . . . . . . . . . . . . . . . . .

BOVS

12-17years . . . . . . . . . . . . . . .

12years . . . . . . . . . . . . . . . . . . .

13years . . . . . . . . . . . . . . . . . . .

14years . . . . . . . . . . . . . . . . . . .

15yeers . . . . . . . . . . . . . . . . . . .

16years . . . . . . . . . . . . . . . . .,,

17years . . . . . . . . . . . . . . . . . . .

Girls

12-17years . . . . . . . . . . . . . . .

12yaars . . . . . . . . . . . . . . . . . . .

13years . . . . . . . . . . . . . . . . . . .

14years . . . . . . . . . . . . . . . . . . .

15years . . . . . . . . . . . . . . . . . . .

16years . . . . . . . . . . . . . . . . . . .

17years . . . . . . . . . . . . . . . . . . .

Sae footnotas at end of table.

3.1 8.6 13.2 0.2 4.8 10.8 -2.4 1.5 5.8 —

5.0

1.6

4.5

1.7

3.2

3.8

2.2

9.0

7.8

9.0

7.9

8.9

8.8

8.0

13.1

13.1

13.2

13.0

13.8

13.2

12.6

0.7

-0.4

-0.1

-0.8

-0.3

-0.3

-0.6

6.5

4.4

5.3

3.6

4.5

4.5

4.1

11.5

10.7

11.2

10.3

10.6

10.2

10.2

-2.6

-2.2

-2.4

-2.3

-2.3

-2.4

-2.4

1.5

1.9

1.5

1.7

1.1

1.0

1.3

6.6

7.3

6.1

6.9

4.5

4.4

5.0

4.3

0.2

4.3

0.6

3.5

2.0

4.2

12.4

12.2

12.7

12.1

13.9

12.5

13.8

1.4

-0.8

0.1

-1.4

-0.6

-1.4

0.2

11.8

9.5

11.3

8.3

10.0

7.7

11.4

8.6

6.5

8.7

7.0

9.0

7.8

9.2

7.1

3.5

5.7

2.4

4.1

2.4

5.6

-2.5

-2.3

-2.2

-2.7

-2.3

-2.4

-2.3

1.3

1,7

1.7

1.4

1.0

0.9

1.6

5.0

6.8

6.4

6.0

4.3

4.2

6.4

5.3

3.4

4.7

3.1

3.0

5.5

9.6

9.0

9.4

8.9

8.7

9.6

13.9

13.9

13.8

13.9

13.7

13.8

0.1

0.1

-0.3

0.1

-0.1

1.5

5.7

5.4

5.0

5.2

4.8

7.0

11.2

11.7

11.0

11.7

11.1

11.5

-2,7

-2.1

-2.5

-2.0

-2.3

-2.4

1.9

2.1

1.4

2.1

1.2

1.1

7.8

7.8

5.7

7.9

4.7

4.6
Tabla21. Medians and quartile points’ inthadistribution ofhearing levels indwikls reaudiometric zaro(ANSl-lW9) forthehtier

earataacll t& frequency andestimates forwmch among Nqroyoutis, bywand *x: United Statas, 1966-70-Con.

2000 Hertz 3000Hertz 4000 Hertz

Age and sex

’26 I

Madian %5 I ’25 I

Median I P75 I ’25 I

Median

Both saxas

12-17 years . . . . . . . . . . . . . . .

Decibels re audiometric zero (ANSI-1969)

-2,8 1.6 6.9 1.0 6.9 12.1 3.8 8.9 13.4

12 years . . . . . . . . . . . . . . . . . . .

13 years . . . . . . . . . . . . . . . . . . .

14years . . . . . . . . . . . . . . . . . . .

15years . . . . . . . . . . . . . . . . . . .

16years . . . . . . . . . . . . . . . . . . .

17years . . . . . . . . . . . . . . . . . . .

Boys

12-17 years...,.....,.. . . .

12 years . . . . . . . . . . . . . . . . . . .

13years . . . . . . . . . . . . . . . . . . .

14years . . . . . . . . . . . . . . . . . . . .

15years . . . . . . . . . . . . . . . . . . .

16years . . . . . . . . . . . . . . . . . . .

17 years . . . . . . . . . . . . . . . . . . .

Girls

12-17vears . . . . . . . . . . . . . . .

-2.6

-3.5

-3.1

-2.4

-2.7

-2.4

-2.6

-2.7

-3.5

-2.2

-3.2

-2.4

-2.2

-2.9

1.5

1.8

1.4

1.9

1.5

1.4

1.6

6.3

8.0

6.9

7.6

6.7

5.4

6.9

5.5

8.0

7.5

7.7

7.6

4.6

6.9

7.0

8.0

6,3

7.4

5.5

6.7

1.5

1.7

0.9

0.2

0.7

0.9

1.9

7.4

7.8

6.8

6.0

6.5

6.6

7.7

12.3

12.6

12.1

12.2

11.4

11.6

12.3

4.1

3.4

3.9

2.1

4.0

5.3

4.3

9.0

8.8

9.0

8.3

8.8

9.3

9.0

13.4

13.5

13.5

13.5

13.0

13.4

13.4

9.0

8,9

9.0

8,6

9.4

9.1

8,7

13.2

13.5

13.3

14.2

13.4

13,1

13.3

1.3

1.8

1.9

1.7

2.0

1.2

1.5

3.1

O.B

1.7

0.6

3.5

2.4

0,2

0.2

2.6

0.3

-0.1

-0.8

-0.1

8.3

7.4

7.5

6.4

8.4

7.6

6.0

6.2

8.1

6.0

5.6

4.0

5.2

12.6

12.8

12.3

11.8

12.4

11.7

11.8

12.0

12.5

11.9

12.7

10.0

11.4

4.7

3.6

4.5

2.2

5.4

5.2

3.3

12 yeare . . . . . . . . . . . . . . . . . . .

13years . . . . . . . . . . . . . . . . . . .

14years . . . . . . . . . . . ..o.. . . .

15years . . . . . . . . . . . . . . . . . . .

16years . . . . . . . . . . . . . . . . . . .

17 years . . . . . . . . . . . . . . . . . . .

-2.5

-3.5

-4.1

-1,8

-2,9

-2.6

1,7

1.8

0.8

2.1

1.1

1,6

3.6

3.3

3.4

1.9

2.4

5.4

8,9

8,7

9.0

7.9

8.1

9,5

13.6

13.4

13,8

12.8

12,5

13,6

See footnotes at end of table.

54
T-blo 21. Medisms and quartile points’ inthedistribution ofhearing levels indecibels reautiometric zero (ANSl-1969) forthe better

aar at each test f requerrcy and astimates for speeds among@ youths, by age and sex: United States, 1966-70-Con.

Age and sex

Both sexes

12-17 years . . . . . . . . . . . . . ,.

12years ...,,,,.......,.. ,,

13 years . . . . . . . . . . . . . . . . ,..

14years . . . . . . . . . . . . . . . ... .

15 years . . . . . . . . . . . . . . . . . . .

16years, . . . . . . . . . . . . . . . . . .

17 years, , ., . . . . . . . . . . . . . . ,

Boys

12-17 yeers ..,.....,...,.,

12 years . . . . . . . . . . . . . . . . . . .

13yeers . . . . . . . . . . . . . . . . . . .

14years ..,.,,.....,.. . . . . .

lbyears . . . . . . . . . . . . . . . . . . .

16years, ,, ., ...,..., . . . . . .

17y*ars, , a .,, . .,.,,,... . . .

Girls

12-17 years . . . . . . . . . . . . . . .

12years . . . . . . . . . . . . . . . . . . .

13yeers ... .,, ,o .,.,., ..,,.

14yaars ., . ., . . . . . . . . . . . . . .

15yesrs .,,.,..,..,,. . . . . . .

16yeam . . . . . . . . . . . . . . . . . . .

17years, .,,...,.,,,,,,,, . .

— —

6000 Hertz 8000 Hertz S@ech2

P25 Median P75 ’25 Median P75 ’25 Median P75 ,

Decibels re audiometric zero (ANSI-1969)

3.4

3,0

1,5

4,1

3.6

3,8

5,2

4.0

2.7

1,1

4,4

5.5

5.0

6,3

2.8

3.3

2,1

3.8

1,9

3.0

3.1

9.2

9.0

7,8

9.4

9.9

9.2

10,0

9,3

8.4

7.3

9.2

10.6

10.1

10.5

9,0

9,8

8.3

9,6

8.9

8.5

9,3

14.3

14.0

13.6

14.2

16,3

14.0

14.7

14.2

12.9

13.7

13.0

16,4

16.3

14,7

14.4

15.9

13.6

14.8

16.1

13.0

14.7

-0.7

-0.7

0.0

-0.7

-0.7

-1,2

-1.1

5.0

5.3

6,1’

5.2

5.7

3.7

4.3

t

-0.9 4.6

-0,4 5.1

-1,0 4.3

-0.8 4.6

-1,1 6,7

-1.5 3.3

-1.0

-0.5

-1.1

1.4

-0.7

-0.4

-1.0

-1.2

4.5

5.5

5.5

7.4

5,8

4.7

4.2

4.2

11,6

11.4

11.9

11.7

12.5

10.5

11.2

11.5

11.5

11.6

11.2

13.4

9,9

11.3

11.6

11.3

12.2

12,1

11.5

11,0

11,0

-0,1

0,3

0.0

0.0

-0.4

-0.6

0.0

-0,4

0.0

-0.6

0.8

-0.8

-1.0

-0.7

0,2

0.8

0,7

-0,7

0,0

-0.1

0,8

4.8

5,8

5.1

5.0

4.3

3.9

4.9

4.3

5,2

4.0

6.5

3,7

3.1

3.6

5.4

6.3

6.3

3.8

5,1

4.8

6.3

10.5

10,8

10.8

10.7

10.2

10.0

10.3

10.1

10.6

9.8

11.6

9.3

9.3

9.3

10,8

11.0

11.6

9,6

11.0

10.4

11.0

Ip

zbmediamnnd ’75 arathe points in thedistribution of haaring Ievelsbalow which 25,50, and75Percant of thechildren, remactlvoiv fell.

2Av&ga of haaring Iavals at 500, 1000, end 2oo~ Hartz.

55
Table 22. Mean hearing levels re audiometric zero (ANSI-1969) at each tast frequency and estimatesfor speech in the batter ear among

youths by rqion, age, and sax: Unitad States, 1966-70

250 Hartz 500 Hertz 1000 Hertz

Iortheast Midwest South West Northeast Midwest South West Northeast Midwest South West

Age and sex

Both saxes Decibels re audiometric zero (ANSI-1969)

12-17 years.

12yeers . . .

13 years . . .

14 years . . .

15years . . .

16 years . . .

17 years . . .

Boys

12-17 years.

12years . . .

13 years . . .

14 years . . .

15years . . .

16years . . .

17years . . .

Girls

12-17 years.

12 years . . .

13 years . . .

14 years . . .

15years . . .

16years . . .

17years . . .

8.0 10.0 B.8 9.4 5.7 5.6 6.9 5.6 1.6 1.0 2.1 1.8

_ .

8.2

7.9

6.4

6.4

6.0

6.4

6.8

7.8

7.5

6.6

6.0

6.4

6.3

7.0

8.6

8.3

6.2

6.6

5.6

6.6

6.1

5.0

5.8

5.4

5.6

5.2

5.8

1.6

1.4

2.0

1.8

1.4

1.0

2.1

1.4

1.8

0.6

1.2

0.8

0.4

1.3

2.2

2.0

0.8

0.9

1.0

0.8

0.8

2.8

2.6

2.0

1.8

1.6

1.8

2.0

2.0

1.2

2.0

1.2

2.0

2.0

2.1

1.9

1.8

2.2

2.2

2.1

2.6

1.4

7.8

7.6

7.B

8.4

8.0

8.2

8.0

8.0

7.4

8.0

9.0

8.2

8.0

7.9

9.6

11.2

9.2

10.1

9.6

10.4

10.0

10.6

9.1

8.2

7.8

8.6

8.9

8.6

9.2

9.4

9.6

9.3

9.6

9.7

9.4

5.8

5.2

5.9

6.4

5.4

5.5

6.2

5.7

6.6

5.4

5.7

5.1

4.B

5.8

9.3

11.2

9.2

9.9

9.5

11.0

10.0

10.2

8.5

8.0

7.2

9.2

8.8

9.1

10.9

9.8

8.5

8.6

7.8

9.0

8.8

9.4

9.6

9.4

9.6

10.1

9.4

9.6

9.4

9.6

9.2

9.8

9.2

6.9

5.7

6.2

7.0

5.B

5.6

5.2

4.6

4.8

5.4

5.7

5.2

5.4

5.B

6.6

5.9

5.9

5.4

5.2

5.3

5.6

6.5

4.9

5.5

4.8

4.6

6.0

5.4

6,4

6.0

5.6

5.2

5.3

6.3

4.8

5.2

5.0

5.4

5.1

2.6

2.1

2.4

2.1

1.6

1.5

1.0

2.4

2.4

2.1

1.7

2.0

1.6

2.2

3.2

2.6

1.9

2.0

1.2

2.0

7.7

8.0

7.6

7.B

7.9

8.4

9.8

11.2

9.2

10.4

9.8

10.0

0.6

0.6

1.4

1.4

1.2

0.6

0.8

1.6

0.2

1.6

0.7

0.1

2.2

0.7

1.8

0.2

2.0

1.2

56
Ttio 22 Meanhearinglavelsreaudiometriczero (ANSI-1W9) at eachtestfrequencyandestimatesfor speechin the better earamong

vouths by reaion. am and aax: United States, 1966-70-Con. ——— ---- -

. -._—_ ,. _.,,.— .——— — ... —

2000 Hertz 3000 Hertz 4000 Hertz

Northeast Midwest South West Northeast Midwest South West Northeast Midwest South West

Age and sex

Both sexes Decibels re audiometric zero [ANSI-1869)

12-17 years. 0.9 4A 8.9 8.6

1.2

0.2

0.8

1.6

0.2

1.2

1.4

2,2

1,0

1.4

2.6

0.1

1.2

0.8 1.4 1.2 5.2 7.2 4.6 6.4 7.9

12yeers . , .

13 years . . .

14 years . . .

i5years . . .

16 years ., .

17years . . .

0.4

1.2

0.6

1,2

0,9

0.8

1.3

1.2

1.6

1.2

1.2

1.1

1.6

0.4 —.

-0.3

0.9

-0.1

1.4

0.8

0.0

1.8

2.4

1.6

1.4

1.0

0.5

1.8

2.6

2.8

1.1

1.2

1.2

1.8

1.2

1.0

0.6

1,5

0.8

1.8

1.4

1.6

5.2

5.2

5.4

5.4

5,0

4.8

6.3

4.0

6.0

4.6

4.8

4.0

4.3

5.6

7.3

8,1

7.1

7.4

7.2

6.2

8.4

5.0

4.2

4.0

4.6

5.0

5.2

6.0

6.5

6.8

6.1

5.6

6.8

6.9

7.2

7.6

6.9

7.8

8.0

7.2

7.6

9.2

9.3

8.5

9.3

8,8

8.4

8.6

8.2

8.2

8.6

8.9

9.3

Boys

12-17 years . 8.8 10.4 10.3

1.4

1.2

2.0

1.6

2.0

1.5

0.8

6.3

6.2

6.6

6.8

6.7

4.9

4.0

5.4

5.8

5.6

5.6

5.2

5.9

3.3

8.1

9.4

7.4

8.6

9.0

7.6

6.0

5.8

5.9

6.0

6.0

6.2

6.1

3.2

7.6

7.3

7.0

5.6

8.2

7.2

5.6

8.2

8.9

8.6

8.8

8.2

10.0

10.2

11.0

8.4

11.6

10.0

10.8

9.8

10.4

10.0

10.2

10.4

11.0

12yaars . . .

13 years . . .

14 years . . .

15years . . .

16 yews . , .

17yaers . . .

Girls

12-17 years.

I-J=

7.0 7.4 6.9

7.3

6.0

6.4

7.0

%

4.2

2.4

1.9

3.2

3.9

4.0

6.4

6.2

5.1

5.4

5.4

6.6

8.2

7.6

8.6

7.0

7.2

5,8

12yeers . . . 0.4

13 years . . . -0.7

14 years . . . 0.1

16years . . . 0.7

16 years . . . 0.3

17 years . . . 1.2

1.2

2.0

2.1

1.4

0.8

-1.0

0.5

0.0

1.0

0.2

1.7

1.2

4.0

4.0

4.0

4.1

3.4

4.8

2.6

4.2

3.6

3.8

2.8

2.9

6.4

6.8

6.8

6.4

5.2

4.6

7.0

9.0

7.1

7.2

6.2

5.4

57
Table 22. Maan hearing levels re audiometric zero (ANSI-1969) at each test frequency and estimatesfor speech in the batter ear among

youths by region, age, and aax: United States, 1866-70-Con.

6000 Hertz 8000 Hertz Speech1

Age and sex

Northeest Midwest South Weat Northeast Midwest South West Northeast Midwest South West

Both 5eXSS

I

Decibels re audiometric zero (ANSI-1969)

12-17 years.

12years . . .

13 years . . .

14 years . . .

15years . . .

16years . . .

17 years . . .

Boys

12-17 years.

12years . . .

13 years . . .

14years . . .

15 years . . .

16 years . . .

17years . . .

Girls

12-17 years.

12years . . .

13 years . . .

14 years . . .

15years . . .

16 years . . .

17years . . .

8.8 11.2 12.4 12.1 5.6 7.1 5.5 4.9 4.7 5.7 5.0

5.4

4.5

5.4

4.8

5.2

5.0

5.4

8.7

8.2

8.5

8.4

8.6

9.6

9.8

10.1

9.8

11.0

10.8

12.0

11.8

11.7

12.5

11.6

12.4

12.0

12.7

13.4

12.2

14.2

11.6

11.8

12.3

11.6

13.6

11.8

13.5

6.1

6.2

5.4

5.2

5.0

5.0

6.4

7.0

7.5

7.0

7.8

6.2

7.1

7.6

9.0

9.6

8.0

8.9

8.3

8.4

9.6

6,2

5,6

5.5

5.2

5,4

4.9

6.3

5.2

4.4

5.2

5.3

4.4

5.0

5.4

4.6

5.4

4.4

5.0

4.4

4.2

4.9

6.6

6.4

5.6

5.4

5.0

5.2

5.8

9.8

9.4

9.4

9.8

11.3

11.6

7.4

11.0

11.8

12.2

12.4

13.8

14.2

9.8

8.6

10.2

9.3

11.6

9.6

9.5

12.5

14.1

12.7

14.6

15.4

15.9

10.5

10.8

10.6

11.3

10.8

10.8

8.4

12.6

13.2

13.8

13.2

14.7

13.6

10.6

10,4

10.4

10.7

10,0

12.6

9.4

7.8

6.7

6.0

6.2

6.1

5.5

4.6

7.2

7.2

7.6

7.9

7.6

7.8

6.6

6.8

7.8

6.4

7,6

4.7

6.6

10.2

11.4

8.1

9.5

9.0

9,8

7.7

7.8

7.7

8.0

8.3

7.4

7.1

6.3

6.9

5.6

6.8

6.6

5.6

4.6

6.2

4.4

5.4

3.6

4.2

4.2

6.2

5,0

5.7

6.0

4.4

5.2

4.4

4.2

3.7

4.4

4.6

4.4

4.8

5.0

5.6

4.9

4.8

4.6

4.6

4.4

4.2

5.2

4.0

5.2

4.2

3.8

6.8

6.3

5.4

5.2

5.5

5.6

5.6

6.4

6.6

5.7

5.6

4.4

4.6

5.4

4.8

5.7

5.5

5.4

5.2

4.7

G

4.2

5.0

4.0

5,0

4.8

6.6

7.6

7.3

7.4

7.9

8.2

4.4

5.6

4.6

4.4

4.0

4.4

lAvaraw hearing levelsat 500, 1000, and 2000 Hertz.
,

T~blt! 23. Medians and quartile poins’ in the distribution Of hearing levels in decibels re audiometric zero (ANSI-1969) for the bettar

ear at each test f requency arxi estimates for speech among youths in the Northeast, by age and sex: Unitad States, 1966-70

Age and sex

250 Hertz I

500 Hertz I1000 Hertz

P25 Ihledian Median P75

I

’25 Median P75

Both sexes Decibels re audiometric zero (ANSi-1969)

12-17 years, . . . . . . . . . . . . . ,

12years, ,,, ,, . ., . .,..,...,

13years, ,,, ... ,,. ,.. ,m. . . .

14years, , . . . . . . . . . . . . . . . . .

15years, ,, .,,,...,,,.,,. . .

l~years ..,,.,,..,,,,, ,.,.,

17years . . . . . . . . . . . . . . . . . . .

Boys

12-17years, ., . . . . . . . . . . . .

12years .,, . . . . . . . . . . . . . . . .

13years . . ... ,,... . . . . . . . . .

14years, .,......,,.. . . . . . .

16years . . . . . . . . . . . . . . . . . . .

16years, ,,, ,, ..,,,..,,., ,,

17 years ., . ., .,....., . . . . . .

Girls

12-17years, . . . . . ..m.m ,,,,

12years, ... , . . . . . ..m... ,,,

13years . . . . . . . . . . . . . . . . . . .

14years . . . . . . . . . . . . . . . . . . .

15years, . . . . . . . . . . . . . . . . . .

16years, .,.,,....,,,. . . . . .

17years . .,, , . . . . . . . . . ,,.,.

See footnotes at end of table.

2,9 8,2 12.5 0.0 5.3 10.7 -2.6 1.0 4.5

2.2

3.4

2.5

2.5

3.6

3.4

3,4

7.9

8.2

7.9

8.1

8.4

8.6

8.3

12.4

12.2

12.3

12.7

12.4

13.0

12,4

-0.1

-0.4

0.2

0.7

0.0

-0.1

0.7

5.3

4.4

5.4

6.3

5.3

5.0

6.3

10.8

10.0

10.9

11.2

10.6

10.5

11.1

1.0

0.9

1.4

1.0

0,9

0.6

1.4

-2.7

-2.6

-2.1

-2.8

-2.6

-2.9

-2,4

4.6

4.4

4.8

4.7

4.4

4.0

5.4

2.8

3.0

2,8

5.1

4.4

3.2

2.4

8.1

8.0

7.9

9.2

8.7

8.4

8.0

12,2

12,0

11.9

13.2

12.6

12.7

12,5

0.8

0.3

0.8

1.1

0,8

0,1

-0,5

6,6

5.8

6.4

6.7

6.7

5.3

4.2

11,7

10.6

11.2

11,4

11.0

10.5

10.1

9.8

9.0

10.4

11.0

10.0

10.4

-2.3

-2.4

-1.8

-2.7

-2.6

-3.0

-2.8

-3.1

-2.8

-2.4

-2,9

-2.6

-2.8

1,5

1.5

2.0

1.1

1.0

0.8

0.6

0.4

0,4

0.8

0,8

0.8

0.4

6.0

6.0

6.8

4.9

4.6

4.6

3.9

3.9

3.6

3.9

4.5

4.2

3.5

1.6

4,0

2,2

0,9

2,9

3,6

7,6

8.5

7.9

6.8

8,1

8.8

12.5

12.4

12.7

12.1

12.2

13.3

-0.8

-1.0

-0.5

0.3

-0.6

-0.3

4.0

3.2

4.3

5.8

3.9

4.8

59
Table 23. Medians and quartile points’ in the distribution of hearing Ievals in decibels re audiometric zero (ANSI-1869) for the be#er

ear at aach test frequency and estimates for spaech among youths in the Northeast, by age and sex: United States, 1866-7@-Ctm.

_-

Age and sex

Both sexes

12-17 yeers, . . . . . . . . . . . . . .

12years . . . . . . . . . . . . . . . . . ,.

13years . . . . . . . . . . . . . . . . . . .

14years . . . . . . . . . . . . . . . . . . .

15 years . . . . . . . . . . . . . . . . . . .

16years . . . . . . . . . . . . . . . . . ,.

17years . . . . . . . . . . . . . . . . . .,

Boys

12-17 years . . . . . . . . . . . . . . .

12 years . . . . . . . . . . . . . . . . . . .

13years, . . . . . . . . . . . . . . . . . .

14years . . . . . . . . . . . . . . . . . . .

15years, . . . . . . . . . . . . . . . . . .

16 years . . . . . . . . . . . . . . . . . . .

17 years . . . . . . . . . . . . . . . . ,,,

Girls

12-17 years . . . . . . . . . . . . . . .

12years . . . . . . . . . . . . . . . . . . .

13years . . . . . . . . . . . . . . . . . . .

14years . . . . . . . . . . . . . . . . .,.

15 years . . . . . . . . . . . . . . . . . . .

16years .,..........,,.. . . .

17years, . . . . . . . . . . . . . . . . . .

.—, ,

2000 Hertz I

3000 Hertz I

4000 Hertz

’25 Median P75 ’25 Median p7i5 ’25 Medkm ~75

Decibels re audiometric zero (ANSI-1969)

-3.2

-3.0

-3.6

-3.4

-2.8

-3.5

-3.0

-2.9

-2.3

-3.4

-2,8

-2.5

-3.5

-3.0

-3.6

-3.7

-3,8

-4,1

-3,0

-3.6

-3.0

0.6

0.8

0.1

0.5

1.4

0.2

0.9

1.0

1.5

0.6

0.9

2.2

0.1

1.1

0,2

0.1

-0.3

-0.1

0.7

0.2

0.7

4.5

4.6

3.9

4.3

6.1

3.9

4.9

5.0

5,8

4.6

4.6

8.3

3.7

5.6

4.0

3.9

3.2

3.9

4.4

4.0

4.5

-0,5

-0,3

-0.5

-0.7

-0.2

-0.8

-0.8

0.3

0.3

C.2

0.1

1.2

0,8

-0,9

-1.8

-0.9

-1.1

-1.7

-1.1

-1.8

-0.7

4.5

4.9

4.8

4.4

4.7

3.9

4.4

5.9

6.2

5.8

5.5

6.9

6.6

4.3

3,4

3,8

3,9

3.3

3.0

2.1

4,5

10.5

10.6

10.7

10.6

10.6

10.2

10.2

11,3

11.4

11.3

11.3

11.8

11.7

10,2

9.4

9.6

9.9

9,5

8.9

7.5

10.1

0.5

0.0

0.9

0.5

0.2

0.6

1.2

1,2

0.4

1.7

1.6

0.2

1.7

2,0

0,0

-0,3

0.3

-0.4

0.3

-0.1

0.5

6.3

5.6

6.9

6.1

5.6

6.5

7.1

7.0

6.4

7.6

7.3

5.4

7.6

7.7

5.5

4.9

6.1

4.4

5,8

5,2

6.5

11.5

11.4

11.8

11”3

10.8

11.6

12.0

12.0

12,3

12.3

11.9

10,7

12.3

12.3

10,9

10.5

11.3

10.5

10.8

10.8

11.7

See footnotes at end of table.

60
Table 23. Mediam and quartile points’ in the distribution of hearing levels in decibels re audiometric zero (ANSI-1989) for the batter

@arat each test frequency and estimates for speech among youths in the Northeast, by age and sex: U nitad States, 196B-70-Con.

——.—

Age and sex

Both sexes

12-17 years, ,, . . . . . . . . . . . .

12 years . . . . . . . . . . . . . . . . . . .

13yews . . . . . . . . . . . . . . . . . . .

14years . . . . . . . . . . . . . . . . . . .

15years .,, ,, . . . . . . . . . . . . . ,

16yeiw$ .,.,........,.,., . .

17years, . .,, ,, . . . . . . . . . . . .

Boys

12-17 years . . . . . . . . . . . . . . .

12years . . . . . . . . . . . . . . . . . . .

13years . . . , .,, ,, .,,, . ...,.

14years . . . . . . . . . . . . . . . . . .,

15 years . . . . . . . . . . . . . . . . . . .

16 years.,...,,,,,.,,,,, ,..

17 years . . . . . . . . . . . . . . . . . . .

G iris

12-17 yekirs . . . . . . . . . . . . . . .

I

12 years, . .,, .,, ,, .,..,. ,,.

13years . . . . . . . . . . . . . . . . . . .

14years, ,, .,..,,,,,.. . . . . .

15years . . . . . . . . . . . . . . . . . . .

16years, ,,, ,, . . . . . . . . . . . . .

17 years, ,, . . . . . . . . . . . . . . . .

6000 Hertz I

8000Hertz

I

Speech*

P25 I Median I P75 ’25 Median I P75 I P25 I Median I P75

Decibels re audiometric zero (ANSI-1969)

1.9 8.2 13.6 -1.2 4,6 11.1 -0.5 4.1 9.8

0.6

1.0

2.2

2,7

2.2

4.6

3.2

1.5

1.6

3,1

4,7

4.8

5.9

0,9

6.8

7.4

8.3

8.7

8.7

9.4

9,2

12.7

13.6

13.3

13,7

14.2

13.9

14.5

-1.2

-0.9

-0.7

-1.4

-1,8

-0.8

-0.7

4,5

5.6

5.3

4.0

3.4

4.8

5.3

11.5

12.0

11.0

10.8

10.5

10.7

11.7

-0.1

-0.8

-0.4

-0.2

-0.9

-0.4

0.0

4.8

3.5

4.3

4.7

3,4

4.3

5,2

10.2

9.1

9,9

10.3

9.0

9.8

10.4

7.9

8.1

8.8

9.8

10.2

10.7

7.2

5.6

6.6

7.6

7.5

7.3

8.2

13.5

14.4

13.8

14.7

16,8

16.0

12.6

11.9

12.8

12.7

12.7

12.8

12.6

-0.5

-1.0

0.2

-1.0

-1.1

-0,6

-1.6

-1.8

-0.7

-1.6

-1.9

-2.6

-1.1

6.1

5.2

6,5

4.8

3,9

4.6

4,0

3.3

6,0

3.8

3.2

2.9

5.1

13.3

11.9

11.6

11.4

11.1

10.6

10.5

0.5

-0,1

0,1

0.5

-0.6

-0.2

-0.9

6,0

4.8

5.3

6.0

4.2

4.8

3.3

10.9

10.2

10.5

11.0

9.6

10.1

8.9

-0.1

0.5

1.2

1.4

0,7

2.8

9.7

12.1

10.2

10.2

10.0

10.8

-0.6

-1.3

-0.8

-0.8

-1.1

-0.7

3,8

2.4

3.4

3.5

2.9

3.8

9.4

7.5

9.0

9.3

8.2

9.4

‘P2=j,medla n, and P75 are the points in the distribution of hearing Iavels below which 25, 50, and 75 percent of the children, respactivel y fal L

2Average of hearing levels at 500, 1000, and 2000 Hertz.

61
Table 24. Medians and quartile points’ in tha distribution of hearing levels in decibels re audiometric zero (ANSI-1969) for the better

eer at each test frequency and estimates for speech among youths in the —~Midwest by age and sex: United States, 1866-70

# :

250 Hertz I500 Hertz I1000 Hertz

Age and sex

Both sexes

12-17 years.....,.....,,..

12 years . . . . . . . . . . . . . . . . . . .

13years . . . . . . . . . . . . . . . . ,.,

14years . . . . . . . . . . . . . . . . . . .

15 years ., . . . . . . . . . . . . . . . . .

16 years . . . . . . . . . . . . . . . . . . .

17years . . . . . . . . . . . . . . . . . .,

Boys

12-17 years . . . . . . . . . . . . . . .

12 years . . . . . . . . . . . . . . . . . . .

13years . . . .. o . . . . . . . . . . . . .

14years . . . . . . . . . . . . . . . . . . .

15years . . . . . . . . . . . . . . . . . .,

16years . . . . . . . . . . . . . . . . . . .

17 years . . . . . . . . . . . . . . . . . . .

Girls

12-17 years . . . . . . . . . . . . . . .

12 years ., ., . . . . . . . . . . . . . . .

13years .,, . . . . . . .. . . . . . . . .

14years . . . . . . . . . . . . . . . . . . .

15 years . . . . . . . . . . . . . . . . . . .

16yaars . . . . . . . . . . . . . . . . . . .

17years . . . . . . . . . . . . . . . . . . .

See footnotes at end of table.

~25 lMedianl~75 ] P25 lMedian[ P75 I ~25 Ihledianl P75

Decibels ra audiometric zero (ANSI-1969)

6.1 9,9 13.8 -0.1 4.9 10.0 -2.9 0,6 4,2

5.6

6.9

5.5

6.0

6.0

6,4

6.2

10.8

11.4

10.4

10.5

9.8

9.9

10.8

11.0

11,6

10.7

10.7

10.4

10.2

10.2

-3,1

-2.9

-3.0

-2.9

-2,B

-3.0

-2,8

-2.4

-2.8

-3.0

-2.9

-2.9

-2,6

-3.1

0,7

1.1

0.4

0.7

0,5

0.5

0.8

1,3

1,2

0.5

0.6

0.5

0.7

0.5

4.4

5.2

3.8

4.4

3,9

3.9

4.3

5.1

5.5

3.9

4,1

3.9

3.9

4,1

9,6

10.7

9.4

10.0

9.7

10.2

10,0

13.7

14.6

13:3

14.0

13.3

14.1

13.8

13,3

14,6

13.1

13.7

13.3

14.7

13.8

0.0

0.6

-0.2

0.0

-0.6

-0.5

0.1

0.2

0.7

-0.1

0,3

-0.2

-0.2

-0.3

5.2

6.3

4.7

5.2

4.0

4.1

5.4

5.5

6.5

4,8

5.6

4.7

4.6

4.5

9.4

11.1

9.5

9.8

9.5

10.7

9.9

9.9

10.4

9.2

10.2

9.8

9,B

5.5

7.5

5.8

6,0

5.8

6.8

5.9

5.7

6,3

5.0

6.1

6.3

6.1

14.0

14.5

13.5

14.3

13.3

13.5

-0,1

0.5

-0.2

-0.3

-1.0

-0.6

4.9

6.1

4.6

4.6

3.2

3.8

10.6

11.2

10.0

10.3

9.1

9.6

-3.7

-3.0

-3.0

-2.9

-2.8

-3.3

0,0

1.0

0,4

0,9

0.5

0,3

3,B

5.0

3.8

4.8

3,8

3.9

62
‘Table 24. Medians and quartile points’ inthed6tribution ofhearing levels indecibeIs reaudiometric zero (ANSl-1969) forthe better

ear at each teat frequency and asimatas for speech among youths in the Midwest, by age and sax: United States, 1968-70-Con.

—. . ..— .——

2000 Hertz 3000 Hertz 4000 Hertz

Age and sex

’25 Median P75 ’25 Median P75 ’25 Median P75

Both wxes

12-17 years, ,,, ,, .,.,.,.,,

I

-3.5

12 years,.,,,,,.,,,,,,, ,., , -3.5

13yeers, , . . . . . . . . . . . . . . . ,. -3.8

14years .,,,,.,...,.,,,, ,., -3.6

15years, ,,. .,, ... ,,o, ,. o,, -3.3

16yeers, ,,, ,,, , .,,,....,,. -3,4

17 years . .,, . . . . . . . . . . . . . . . -3.3

Bovs

12-17 years, ,,, . . . . . . . . . . .

12yaars, ,,, ,, . .,, ,., .,,.,.

13yaars, ,,, ,,, ,., ,,o,.,, ,,

14years, ,. m. ., .,...,... ,.,

15years, . . . . . . . . . . . . ,,.,,,

16yeers . . . . . . . . . . . . . . . . . . .

17yeers, ,., am..,,...,.. . . .

Girls

12-17yaars . . . . . . . . . . . . ,,.

12yaars, ,,, .,, . ., ...,,.., . .

13yaars, ,, .,, ,, .,,..... . . .

14years, ., ., ., ..,..,... . . .

15years, .,, o,, .,.....,, . . .

16years, .,,,.,,,,..,,,,, ,,

17years . ., .,, . . . . . . . . . . ,..

-3.4

-3,1

-3.9

-3,4

-3.7

-3,5

-2.8

-3.6

-4,0

-3,8

-3,7

-2.9

-3.4

-3,8

0.5

0,4

0.3

0.3

0,8

0.5

0.5

0.8

0,9

0.7

0.6

0.7

O.B

1.2

0,2

-0.1

0,0

0.0

1.0

0,3

-0,1

Decibels re audiometric zero (ANSI-1969)

4.4

4.4

4.5

4.2

5.0

4.4

4.3

5.1

4.9

5.8

4.7

5.2

5.0

5.8

3,9

3,8

3,8

3.6

4,9

3,9

3.6

-1,0

-1.5

-0,7

-0.9

-1.0

-1.1

-0.9

-0.2

-0.8

0.2

-0.4

-0.4

-0.1

0.4

-1.7

-2.1

-1.4

-1.4

-1.5

-2.0

-1.7

3.6

2,9

4.4

3.9

3.3

3.8

3.7

5.1

4.1

6.0

5.1

4.6

5.3

5,8

2.5

2.0

3.2

2.9

2.2

2.5

2,3

9.8

9,0

10,4

9.8

9,8

9.9

9.5

10.9

10.3

11.4

10.7

11.2

10.8

10.9

8,2

7,3

9.2

8,6

7.3

8.6

7.6

2.1

1.8

3.8

2,4

2.2

0,9

2.0

2.7

-

1.8

3.4

2,3

1.9

2.6

5,1

1.6

1,9

4.2

2,6

2,6

-0.3

0.3

7.9

7.6

8.7

8.1

7.9

7.0

7.7

8,4

7.7

8,7

8.1

7.9

8.5

9.3

7.4

7.5

8.7

8,0

7,9

5.3

6,2

12,5

12.2

12.9

12.7

12.5

12.5

12.2

13.1

-

12.6

13.2

13.0

13.1

13.5

13.5

11.9

;1.9

12.6

12.4

12.0

11.2

10.8

See footnotes at end of table.

63
Table 24. Medians and quartile points’ in thediSributiOn ofhearing lwelsin decibels maudiometric zero (ANSl-lW9) fortheht&

ear at each test f requency and estimates for speech among youths in the —Midwest by age and sex: Unitad St etes, 1966-70–Con. t

Age and sex

Both sexes

12-17 years . . . . . . . . . . . . . . .

12 years . . . . . . . . . . . . . . . ,,. ,

13years . . . . . . . . . . . . . . . . . ,,

14years . . . . . . . . . . . . . . . . . . .

15yeers . . . . . . . . . . . . . . . . . . .

16years . . . . . . . . . . . . . . . . . . .

17 years . . . . . . . . . . . . . . . ,.. ,

Boys

12-17 years . . . . . . . . . . . . . . .

12 years . . . . . . . . . . . . . . . . . . .

13 years . . . . . . . . . . . . . . . . . .

14years, ...,.......,.,.. . .

15 years............,.. . . . .

16years ...,,,..,....,.. . . .

17 years . . . . . . . . . . . . . . . . . . .

Girls

12-17 years . . . . . . . . . . . . . . .

12 years, . . . . . . . . . . . . . . .,, ,

13years ., . . . . . . . . . . . . . ,.,.

14yeara . . . . . . . . . . . . . . . . . . .

15yeara . . . . . . . . . . . . . . . . . . .

16years . . . . . . . . . . . . . .,.,,.

17 years . . . . . . . . . . . . . . . . . . .

6000Hertz

’25 Median P75

5.3 10.2

3.7 9.1

5,4 10.4

4,8 10.0

6.1 10.8

5,5 10.2

5,5 10.8

6.0 11.0

5.0 9.8

6.3 11.0

6.2 11,0

5.9 10.7

6,2 11,3

6.0 12.7

4.3 9.4

2,7 8.4

3,9 9.7

2.6 8,8

6.3 10.9

4.7 9.2

5.2 9.7

8000 Hertz I

Speech2

P25 \Medianl P75 I P25 \Medianl P,5

Decibels reaudiometric zero (ANS1-1969)

15.2

13.8

15.8

15.2

16.2

14.8

17.2

17.1

14.6

16.5

16.8

16.4

18,2

20.3

14.2

13.1

15.1

14,2

16.1

13,5

14.3

0.0

-0.6

0.6

0.3

0.0

-0.7

0,3

0.0

-1.0

0.3

0.8

0.0

0.0

0.0

0.0

-0.2

0,9

-0.3

0.1

-1.3

0.7

6.5 I 12.6

5.9

7.3

7.0

6.5

5.9

6.5

12.4

13.4

12.6

13.0

11.9

12.3

---P

5.3 12.7

7.0 13,0

7.2 12.6

6.8 13,2

6.8 13.0

5.8 12.4

-1-- 6.5 12.4

6.4

7.5

6.8

6,2

5,1

6.9

12,2

13,8

12.6

12.7

10.9

12.3

-0.8

-0,9

-0.5

-1.0

-0.6

-1.2

-1,0

-0.8

-0.9

-0.2

-0.8

-0.7

-1.1

-0.8

-0.9

-0.8

-0.6

-1.2

-0.3

-1.2

-1.2

3.3

3.3

4.2

3,0

4.0

2.7

3.0

3.5

3.1

4.B

3.4

3,7

2,8

3.5

3.2

3.4

3.7

2.7

4.3

2,6

2,7

9.1

9,0

10,2

8,6

9,7

8.2

8.5

9.4

8.9

10,7

9.3

9,5

8.6

9,0

8.8

9,0

9,7

8.0

10,0

7.9

7.9

‘Pz5, median, and P75 are the points in the distribution of haaring Iavels below which 25, 50, and75prsrcent of the children, respective y fal 1.

2Averaga of heering levels et 500, 1000, and 2000 Hertz

64
Table 25. Mediam and quartile points’ in the distribution of hearing Ievelsindecibelsre audiometric zero (ANSl-1969) for the better

aarataach tmtfmquency and=timates forspeech among youths inthe~h, byageand~x: Ursitad States, 1966-70

Age and sex

Both sekes

12-17 years . . . . . . . . . . . . . . .

12years, ,,. .,. , . . . . . . .. a..

13years . . . . . . . . . . . . . . . . . . .

14years . . ..m B . . . . . . . . . . . . .

15years, . . . . . . . . . . . . . . . . . .

16years . . . . . . . . . . . . . . . . . . .

17years . . . . . . . . . . . . . . . . . . .

Boys

12-17 years . . . . . . . . . . . . . . .

12yaars . . . . . . . . . . . . . . . . . . .

13years . . . . . . . . . . . . . . . . . . .

14years . . . . . . . . . . . . . . . . . . .

15years . . . . . . . . . . . . . . . . . . .

16years . . . . . . . . . . . . . . . . . . .

17years . . . . . . . . . . . . . . . . ..s

Girls

12-17 years . . . . . . . . . . . . . . .

12years . . . . . . . . . . . . . . . . . . .

13years . . . . . . . . . . . . . . . . . . .

14years . . . . . . . . . . . . . . . . . . .

15years . . . . . . . . . . . . . . . . . . .

16years, . . . . . . . . . . . . . . . . . .

17years . .. m. . . . . . . . . . . . . . .

See footnotes et and of table.

250 Hertz I

500Hertz I1000Hertz

P~~ Median P75 P25 Median P75 P25 Median P75

Decibels re audiometric zero (ANSI-1969)

3.8

6.1

3.1

3.4

1.8

3.7

4.8

8.9

—

10.2

9.0

8.6

7.8

8.9

8.9

---P

5.9

2,8

3.7

1.1

5.0

10,0

8,6

8.5

7.5

9.4

-L5.3 9.2

3.7 9.0

6.4 10.5

3.4 9.7

3.1 8.8

2.5 8.1

2.4 8.2

3.8 8.6

13.4

14.4

14.1

13.0

12.8

13.3

12.8

13.3

14.2

13.2

12.6

12.8

13.8

13.0

13.6

14.6

15.6

13.6

12.8

12.8

12.6

0,9

2.5

1.9

0.7

0.1

0.1

0.6

0.8

2.6

1.7

0.8

0.1

0.0

0.3

0.9

2.3

2.0

0.7

0.1

0.1

0.9

6.7

8,2

7.7

6.6

5.4

5.6

6.3

6.7

8.1

7.5

6.7

5.4

5.9

5.9

6.7

8.2

8.0

6.6

5.3

5.4

6.6

11.8

12,9

12.6

11.7

11.3

10.8

11.4

11.8

12.6

12.2

12.1

11.3

11.1

11.3

11.9

13.3

13.1

11.4

11.4

10.5

11.5

-2.41 1.3

1

-2.1 1-g

-2.2 1.7

-2.4 lm~

-2.4 1.1

-2.6 0.9

-2.5 I.0

-2.5 1.2

-2.3

-2.3

-2.3

-2.4

-2.8

-2,8

-2.2

-1.8

-2,0

-2.5

-2.4

-2.5

-2.2

7.5

1.6

1.4

1.0

1.0

0.9

1.5

2.4

1.9

1.6

1.1

0.9

1.2

5.2

7.1

6.7

6.0

4.5

4.5

4.6

4.9

6.0

6.2

5.3

4.4

4.7

4.6

5,6

8.1

7.0

6.5

4.6

4.2

4.6

65
Table 26. Medians and quartile points’ in the distribrstion of hearing levels in decibels re audiometric zero [ANSI-1969) for the better

ear at each test frequency and estimates for speech among youths in the= by age and sex: Unitad States, 1966-70-Con.

Age and sex

Both sexes

12-17 years . . . . . . . . . . . . . . .

12years . . . . . . . . . . . . . . . . . . .

13years a m. . . . . . . . . . . . . . . . .

14years . . . . . . . . . . . . . . . . . . .

15 years . . . . . . . . . . . . . . . . . . .

16years . . . . . . . . . . . . . . . . . . .

17years . . . . . . . . . . . . . . . . . . .

Boys

12-17 years . . . .. m. . . . . . . . .

12years . .. e . . . . . . . . . . . . . . .

13years . . . . . . . . . . . . . . . . . .,

14years . . . . . . . . . . . . . . . . . . .

15 years . . . . . . . . . . . . . . . . . . .

16 years . . . . . . . . . . . . . . . . . . .

17years . . . . . . . . . . . . . . . . . . .

Girls

12-17 years . . . . . . . . . . . . . . .

12years . . . . . . . . . . . . . . . . . . .

13 years . . . . . . . . . . . . . . . . . . .

14years . . . . . . . . . . . . . . . . . . .

15years .o . . . . .. o . . . . . . . . . .

16years . . . . . . . . . . . . . . . . . . .

17years . . . . . . . . . . . . . . . . ..m

2000 Hertz 3000 Hertz 4000 Hertz

P25 Median P75 P25 Median P75 P25 Median P75

Decibels re audiometric zero (ANSI-1969)

-3.7

-3,3

-3.2

-3.5

-3.9

-3.9

-4.2

-3.5

-2.8

-3.6

-3.3

-4.3

-4.2

-2.9

-3.8

-3.7

-2.9

-3.7

-3.6

-3.5

-6.4

T

0.7 5.0

0,8 4.9

1,2 6.7

1.1 6.7

0.7 !5.7

0.2 4.2

0.0 I4.2

+

1.5 6.7

1.1 6,8

0.8 4.9

0,2 4,8

0.2 4.7

1.0 4.9

+

0.2 4.1

1.4 6.6

1.5 8.0

1.1 6.7

0.1 3.8

-1.2 3.4

0.5

1.2

0.6

0.5

0.1

0.5

0.3

1.5

2.1

1.2

1,2

0.6

1.6

2.6

-0.2

0.4

0,0

0.1

-0.3

-0.4

-1.1

6.5

7.2

6.7

6.3

6.0

6.6

6.2

7.6

8.0

7.7

7.0

7.0

7.8

8.1

5.2

6.2

5.6

5.6

4.9

4.9

3.8

12.0

12,3

12.6

11.6

12.3

12,0

11.4

12.9

13.0

13.7

11.9

13.1

13.2

12.5

11.1

11.6

11.5

11.3

11.5

10.4

14.7

2.2

4.7

2.2

2.2

1.1

2.0

2.1

3,9

5.5

3,5

3.0

2.4

2.9

6.5

1.1

3.3

1,3

1.6

0.2

1.3

-0.3

8.3

9,3

8.2

8.2

7.4

8.2

8.1

9.3

9.7

9.2

8.5

9.2

9.1

9.8

7.1

8.7

7.1

7.8

5.6

7.1

5.8

13.3

13.7

13.1

13.2

13.7

13.4

13.1

14.1

13.9

14.3

13,0

16.1

14.4

14.0

12,6

13.3

11.9

13.4

12.0

12.2

11.6

See footnotes at end of table.

66
Table 25. Medians and quartile pointsl in tl~e clistributimr of hearing levels in decibek re audiometric zero (ANSI-1969) for the better

ear at cat% test frequency and estimates for speech among youths in the S-, by age and sex: United Stat=, 1966-70–Con.

~

Age and sex

Both SLIXt?S

12-17 yams . . . . . . . . . . . . . . .

12 years . ., .,, . . . . . . . . . . . . .

13yrwrs, , = .,,...... . . . . . . .

14yeers . . . . . . . . . . . . . . . . . .

15years . . . . . . . . . . . . . . . . . .

16years . . . . . . . . . . . . . . . . . .

17yea!s . . . . . . . . . . . . . . . . . . .

Eoys

12-17 years, . . . . . . . . . . . . . .

12 years . . . . . . . . . . . . . . . . . . .

13vears . . . . . . . . . . . . . . . . . . .

14vears . . . . . . . . . . . . . . . . . . .

15 years . . . . . . . . . . . . . . . . . . .

16Vears . . . . . . . . . . . . . . . , . . >

17 Vears . . . . . . . . . . . . ..m .,..

—

Girls

12-17 years . . . . . . . . . . . . . . .

12 Vears . . . . . . . . . . . . . . . . . . .

13 years . . . . . . . . . . . . . . . . . . .

14 years . . . . . . . . . . . . . . . . . . .

15years .. m. . . . . . . . . . . . . . . .

16 years...,........,.. . . . .

17years . . . . . . . . . . . . . . . . . . .

6000Hertz 80QOHertz Speech2

J’~5 Median P75 ’25 Median P75 ’25 Median ~75

Decibels reaudiometric zero (ANSI-1969)

5.4 I 11.0

5.4 10.6

5.1 10.9

3,9 10.6

5.4 11.1

6.3 11.6

5.8 11.2

6.4 12.3

18.2

17.0

18.2

18,1

18.7

18.9

18.2

20.3

5.3 11.0 18.6

6.0 12.0 20.2

4.1 11,0 19.0

6,7 12.6 20.9

7,3 12.9 20.8

d--l- 8.5 14.4 21.6

4.0 9“8 15.3

5.5

3.9

3.7

3.5

5.2

2.1

10.3

9.9

10.2

9s8

10,2

8.4

15.3

15.8

17.2

16s1

15.8

13.3

1.2

2.7

2.1

0.2

1.0

0.2

1.3

1.5

3.4

3.8

0.6

0.7

0.0

2.4

0,8

2.1

1.0

G.1

1.2

0.4

0.4

7.9

8.8

8.5

7.0

8.1

7.0

7.8

8.5

9.5

10.2

6.7

8.4

7.0

8.9

7.3

&2

6.9

7.2

7.8

7.0

6.5

13.8

13.9

14.1

13.0

14.4

13.5

13.7

74.7

14.8

17.1

13.6

15.6

14.0

14.7

12,9

13.0

12.3

12.8

13.7

12.9

12.6

-0.2

0.6

0.0

-0.1

-0.4

-0.7

-().6

-0.2

1.0

-0.2

-0.4

-0.5

-0.6

-0,2

-0.2

0,3

0.2

0.3

-0.2

-0.8

-1.0

4.7

6.1

5.0

5.1

4.4

3.7

3.9

4.7

6.6

4.7

4.4

4.1

3.9

4,7

4.6

5.6

5.5

5.7

4.8

3.4

3.2

10.4

11.2

10.9

Io.ri

10.2

9.6

9.8

10.5

11.4

10.9

10.1

9.9

10.1

10.3

10.3

10.9

10.9

10.9

10.6

9.0

9.0

‘P~s, m edlan, and P75 are the points in the distribution of hearing levels balow which 25, 50, and 75 percent of the children, re

spectively fsill,

2Averageot hearing levelsat 500, 1000, and 2000 Hertz.

67
Tabla 26. Medians and quartile points 1 in the di~ributi~n of haaringlevels in dacibals re audiometric zero (ANSI-1969) for the

btiterear atmchteS frquency andewimtm for~@hamo~ youths inthe W@, by~andwx: Unitad Statea,196G70

Age and sex

Both sexes

12-17 years . . . . . . . . . . . . . . .

12 years . . . . . . . . . . . . . . . . . . .

13years . . . . . . . . . . . . . . . . . . .

14years . . . . . . . . . . . . . . . . . . .

15years . . . . . . . . . . . . . . . . . . .

16years, . . . . . . . . . . . . . . . . . .

17years . . .. ti . . . . . . . . . . . . . .

Boys

12-17years . . . . . . . . . . . . . . .

12 years . . . . . . . . . . . . . . . . . . .

13years .. a . . . . . . . . . . . . . . . .

14 years . . . . . . . . . . . . . . . . . . .

15years . . . . . .. u..... . . . . . .

16years . . . . . . . . . . . . . . . . . . .

17 years . . . . . . . . . . . . . . . . . . .

Girls

12-17years . . . . . . . . . . . . . . .

12 years . . . . . . . . . . . . . . . . . . .

13 years . . . . . . . . . . . . . . . . . . .

14 years . . . . . . . . . . . . . . . . . . .

15years . . . . . . . . . . . . . . . . . . .

16 yazirs . . . . . . . . . . . . . . . . . . .

17years . . . . . . . . . . . . . . . . . . .

See footnotes at end of table.

.—— ——

250Hertz 500 Hertz 1000 Hertz

’25 Median P75 ’25 Median P7 ~

‘“ IE!3E

Decibels re audiometric zero (ANSI-1969)

5.6

5.3

5.3

6.0

5.7

5,9

5.6

5.7

4.0

5.5

6.2

5.5

6.2

5.8

5,6

6.1

5.1

5.8

5.8

5.6

5.3

9.4

9.1

9.3

9.6

9.5

9.7

9.4

9.4

8.7

9.3

9.6

9.5

9.6

9.6

9.5

9.6

9.2

9.6

9.5

9.8

9.2

===+==

13.0

13.2

13.1

13.3

13.4

13.2

13.1

12.8

13.1

12.9

13.4

12.9

13.3

13.3

13.2

13.3

13.3

13.2

14.0

13.1

-0.1

-0.4

0.0

-0.1

0.3

-0.5

0.2

-0,1

-0.2

1.1

0.5

1.2

-0.7

-0.4

-0.1

-0.5

-0.8

-0.6

-0.4

-0.2

5.0

5.1

4.5

5.3

4.9

5.9

4.2

5.6

5.2

5.0

6.7

6.0

6.9

3.5

4.4

4.9

4.0

3.8

4.0

4.8

5,2

10.5

10.8

10.1

10.6

10.4

10.9

10.0

10.8

10.7

10.6

11.3

11.2

11.3

9.3

10.2

11.1

9.6

9.7

9.6

10.5

10.8

-2.6

-2.4

-3.0

-2.4

-2.6

-2.5

-2.5

-2.4

-2.5

-2.6

-2.1

-2.3

-2.4

-2.2

-2.8

-2.2

-3.4

-2.7

-2.8

-2.6

-2.8

1.1

1.3

0.7

1.3

0,9

1.1

1.2

1.3

1.0

1.2

1.5

1.6

1.3

1.4

0.9

1.6

0.3

1.1

0.4

1.0

1.0

4.7

=

4.9

4.5

5.0

4.4

4.8

4.9

5.0

4.4

5.2

5.3

6.1

5.0

5.0

4.5

6.3

3.9

4.9

3.5

4.6

4.8

68
Table 26. Madians andquartilepOintsl lnthedistributiOn ofhearing levels indecibe!s reaudiometric zero (ANSl-1969) forthebeRer

ear at sash test frequency and estimates for speech arncrng ycruths in the west, by age and sex: United States, 19E6-70—Crm. —. —

Age and sex

Both sews

.—

12-17 years . . . . . . . . . .. em..

12 years . . . . . . . . . . . . . . . . . . .

13 years , . . . . . . . . . . . . . . . . . .

14 years.......,......,.. . .

15 years . . . . . . . . . . . . . . . . . . .

lt3years . . . . . . . . . . . . . . . . . . .

17years . . . . . . . . . . . . . . . . . . .

Boys

12-17 yeatc . . . . . . . . . . . . . . .

12yeats , X, . . . . . . . . . . . . . . . .

13years r . . . . . . . . . . . . ..o. . .

14 years . . . . . . . . . . . . . . . . . . .

15years . . . . . . . . . . . . . . . . . . .

ltiyears, . . . . . . . . . . . . . . . . . .

17years . . . . . . . . . . . . . . . . . . .

Girls

12-17~ears . . . . . . . . . . . . ..O

12years . . . . . . . . . . . . . . . . . . .

13years . . . . . . . . . . . . . . . . . . .

14years . . . . . . . . . . . . . . . . . . .

15years . . . . . . . . . . . . . . . . . . .

16years . . . . . . . . . . . . . . . . . . .

17years. m........ . . . . . . . . .

Sea foimwtes at end of table.

2000 Hertz 3000 Hertz 4000 Hertz

’25 Median P75 P25 hhedian P75 ’25 Median P75

Decibels re audiometric zero (ANSI-1969)

-3.3

-3.7

-3,9

-2.7

-3.2

-3.2

-3.3

-3.0

-3.1

-3.6

-2.5

-3.0

-2.9

-3.0

-3.6

-4.4

-4,2

-2.9

-3.4

-3.4

-3.5

0.7

0.4

0.2

0.9

0.8

1.0

0.!3

1.0

0.6

0.5

1.4

1.5

1.2

0.9

0.4

0.0

-0.1

0.4

0.2

0.9 ~

I.oi

4.7

4.4

4’..

4,5

4.7

5.6

5.2

5.0

4.3

4,6

5.7

6.9

5.8

4.8

4.4

4.5

3,9

3.8

3,8

5.4

6.1

-1.2

-1.4

-1.6

-1.~

-1.1

-1.1

-0.7

-0.4

-0.9

-0.6

0.2

-0.4

-0.3

0.0

-2.0

-1.9

-2.4

-2.8

-1.7

-1.5

-1.5

3#J

3.4

2.8

3.4

3,5

3.E

4..2

4.8

4.3

4.0

6.1

4.7

5.3

5.0

2.3

2.5

1.6

1.5

2.5

2.5

3.2

9.7

gag

9.1

9.8

gm~

9.s

10.2

1O.a

10.5

10.7

11.5

10.5

11.0

10,7

8.1

9.1

6.8

6.6

8,2

8.2

9.4

2.2

2.1

I .5

1.8

2.7

2.4

2.6

3.9

3.2

4.2

3.9

4.7

3.8

4.0

0.9

1.2

-0.1

0.5

1.4

i.4

1.5

8.1

8.1

7.4

7.7

8.4

8.4

8.5

9.2

8.8

9“0

9.2

9.5

9.5

9.3

6.8

7.2

5.2

6.0

7.3

7.5

7.5

13.1

13.1

12,5

12.8

13.2

13.6

73.3

13.9

13,6

13.4

13.9

14.0

14.6

14.1

12.1

12.4

11.2

11,4

12.3

12.6

12.3

69
Table 26. Medians and quartile points’ inthedistiibution ofhearing levels indmibls reaudiometric zaro(ANSI-1969) forthektter

ear at each test frequency and estimates for speech among youths in the ~, by age and sex: United States, 1966-70-Con.

Age and sex

Both sexes

12-17 years . . . . . . . . . . . . . . .

12years . . . . . . . . . . . . . . . . . . .

13 years . . . . . . . . . . . . . . . . . . .

14years . . . . . . . . . . . . . . . . . .0

15years . . . . . . . . . . . . . . . . . . .

16years . . . . . . . . . . . . . . . . . . .

17years . . . . . . . . . . . . . . . . . . .

Boys

12-17 years . . . . . . . . . . . . . . .

12 years . . . . . . . . . . . . . . . . . . .

13years . . . . . . . . . . . . . . . . . . .

14years .. m. . . . . . . . . . . . . . . .

15years . . . . .. m. . . . . . . . . . . .

16 years . . . . . . . . . . . . . . . . . . .

17 years . . . . . . . . . . . . . . . . . . .

Girls

12-17 years . . . . . . . . . . . . . . .

12yeers . . . . . . . . . . . . . . . . . . .

13years . . . . . . . . . . . . . . . . . . .

14years . . . . . . . . . . . . . . . . . . .

15 years . . . . . . . . . . . . . . . . . . .

16years . . . . . . . . . . . . . . . . . . .

17years . . . . . . . . . . . . . . . . . . .

6000 Hertz 8000 Hertz Speechz

’25 Median P75 ’25 Median P75 Pz 5 Median P75

Decibels re audiometric zero (ANSI-1969)

5.7

5.3

4.4

6.2

5.4

6.7

5,8

6.3

5.2

5.5

7.2

6.2

7.4

6.7

5.1

5.3

3.2

5.2

4.4

6.3

4.6

10.9

10.1

10.1

11.4

10.9

12.2

10.9

11.7

10.3

10.9

12,4

12.0

13.4

12.0

10.1

9.8

9.3

10.4

9.9

11.4

9.7

17.4

14.9

16.1

18.1

17.3

19.5

17.2

19.2

16.8

18.0

19,8

19.3

20.6

19.0

15.3

14.3

14.6

16.3

15.0

18.2

14.7

-1.6

-0.7

-1.7

-1.2

-1.9

-1.4

-2.6

-1.2

-0.4

-1.4

-1,1

-1.4

-0.2

-2.5

-2.0

-1.0

-1.9

-1.3

-2.3

-2.4

-2.7

4.4

5.8

4.3

4.8

3.6

4.6

3.2

5.3

6.4

5,0

5.3

5.0

5.9

3.8

3.6

5.1

3.6

4.3

2.5

3.5

2.5

11.4

11.s

11.2

11.8

11.:

11.1

1o.~

12.C

12,4

11.~

12.2

12.6

11.e

11.1

10.6

11.2

10.8

11.3

9.8

10.5

9.7

-o,!

-0.4

-0.E

-0.4

-0.4

-().~

-w

-0.:

-0.4

-06[

0’..

O.c

-0.4

-0.7

-0,7

-0.3

-1.2

-0.8

-0.8

-0.6

-0.5

4.0

4.4

3.3

4.3

4.2

4.2

3,9

4.5

4.2

4.1

5.6

5.0

4.4

3.7

3.6

4.5

2.7

3.3

3.6

4.0

4.1

9.8

10.3

9.0

10.0

9.7

10.0

9.8

10.1

10.3

9.7

10.7

10.4

1OQ

9.6

9.5

10.3

8.1

9.2

9.0

10.0

10.0

‘P25, median, and P75 are the points in the distribution of hearing levels below which 25, 50, and 75 percent of the children, resr3actively fal1.

2Awrage Of hearing levelsat500,1000, and21)W Hertz.

. .

70
Tablo 27. Moan heating lavalsin dacibals reaudiomatric zaro(ANS1-1869) forthebetter earateach test frequency among youthsin

urban andrural araas,byage and sex: United States, 1966-70

Urban areas

Hertz

250 500 1000 2000 3000 4000 6000 8000

—

Rural areas

Hertz

250 500 1000 2000 3000 4000 6000 8000

Age and sex

—

8oth sexes Decibels re audiometric zero (ANSI-1969) Decibels re audiometric zero (ANSI-1969)

5.2 7.8

.

7.8

8.0

7.4

7.8

7.6

8.2

8.7

12-17 years . , . 6.0

G

6.2

5.8

6.7

5.8

6.6

6.3

G

6.0

6.2

6.2

6.4

5.7

5.8

—

6,8

6.4

5.4

6.0

5.3

5.6

—

1.6

.

2,0

1.7

1.6

1.6

1.6

1.4

2.0

1.0 10.8 6.2 1.5

=

1.8

1.8

1,6

1.4

1.4

0.9

1.6

1.2

1.1

1.6

1.4

1.4

0.8

0,7

1.6

5.6 8.4

8.3

9.0

8.0

8.3

8.6

7.8

10,0

11.9 7.5

-

8.2

7.4

7.4

7.9

7.0

7.2

9.0

9.4

-

9.4

9.7

8.9

9.2

9.4

9.7

9.4

E

9.2

9.0

9.0

9.6

9.9

9.4

G

0,2

8,8

9.3

9.2

9.4

—

8.8

G

9.0

8.5

8.6

8.4

9.0

8.8

G

9.2

8,3

8.8

8.4

9.0

8.8

—

9.6

8,6

8.7

8.5

8,3

8.8

—

5,7

.

6.4

6.0

6.0

5.6

5.0

6.2

5.8

G

6.6

6.3

6.0

4.9

5.3

5.6

—

7.0

5.4

5.6

5.2

5.0

4.9

—

. _ .

12 years . . . . .

13 years . . . . .

14yaars . . . . .

15 years . . . . .

16years . . . . .

17 years . . . . .

*.0

0.s3

1.0

1.2

1.2

1.1

1.5

5.1

5,2

5.0

5.2

5.0

5.2

6.2

9.9

10.4

10.4

11.0

11.4

11.4

11.8

6.4

7.0

6.0

6.2

5.8

6.0

6.6

5.4

6.0

5.7

6.2

5.8

4.8

7.0

11.0

11.9

11.6

12.0

13.4

11.5

13.9

BOYS

12-17 years . , ,

12years . . . . .

13years ., . . ,

14years . . . . .

f 5 years . . . . .

16years . . . . .

17 years . . . . .

2.4

1.8

1.9

1.8

1.9

2.C

1.3

1.6

1,7

1.3

7.2

1.2

1.0

1,8

1,0

1.5

1.6

1.6

1,4

0.6

0.3

0.8

0.4

0.8

0.8

0.8

6.3

6.0

6.2

6.2

6.4

6.3

4.0

G

4,6

3.6

4.2

3.7

4,2

8.6

8.4

8.4

8.4

8.8

9.8

6.8

10.6

11.0

11.6

77.9

12.8

13.7

9.6

9.1

9.8

9.2

10.0

10.3

9.2

6.7

6.9

6.2

6.6

6.4

6.7

6.0

6.0

7.2

5.8

5.8

5.2

5.3

1.8

2.6

1.7

1.3

1.2

1.0

1.4

1.8

0.9

1.4

1.6

1.5

0.8

1.6

2.7

1,2

1.6

0.4

1.8

0.6

0.6

0,2

1.4

1.1

1.1

-0.4

6.3

8.0

6.6

7.6

7.2

6.0

4.2

9.6

10.8

8.8

10,6

9.8

10.0

6.6

7.0

6.8

7.3

5.9

7.2

5.4

12.9

13.8

12.8

13,9

15.7

14.4

9.7

9.0

9.7

10.5

10.1

10.6

8.4

9.6

9.6

8,0 ‘

9.5

9.0

7.9

5.9

6.6

5.0

6.6

6.2

4.4

6.3

Girls

12-17 years . . .

12years . . . . .

13 years . . . . .

14years . . . . .

15 years . . . . .

16years . . . . .

17years ... .,

6.9

7.5

6.6

7.2

6.4

6.6

4.6

3.8

4,8

4.6

3.9

3.4

71
Table 28. Mean hearing levels in decibels re audiometric zero (ANSI-1869) for the better ear at each teat frequency among youths in

500 Hertz

Both sexes 12-17 years .

Boys 12-17 years . . . . .

Girls 12-17 years . . . . .

1000 Hertz

Both sexes 12-17 years .

Boys 12-17 years . . . . .

Girls 12-17 years . . . . .

2000 Hertz

Both sexes 12-17 years .

Boys 12-17 years . . . , .

Girls 12-17 years . . . , .

3000 Hertz

Both sexes 12-17 years .

Boys 12-17 years . . . . .

Girls 12-17 years . . . . .

4000 Hertz

Both sexes 12-17 years .

Boys 12-17 years . . . . .

Girls 12-17 years . . . . .

6000 Hertz

Both sexes 12-17 years .

Boys 12-17 years . . . , .

Girls 12-17 years . . . , .

8000 Hertz

Both sexes 12-17 years .

Boys 12-17 years . . . . .

Girls 12-17 years . . . . .

Speech’

Both sexes 12-17 years .

Boys 12-17 years . . . . .

Girls 12-17 years . . . . .

8.3

7.9

8.7

5.6

5,8

5.4

1.5

1,6

1.4

0.5

1.0

0.0

5.2

5.8

4.4

6,9

7.4

6.5

9.1

9.6

8.6

4.8

4.7

4.8

4.8

5.0

4.6

10.4

10.6

10.1

6.2

6.5

6.0

1.0

1.2

0.7

1.0

1.0

1.1

5.1

5.8

4.4

7.6

8.2

7.2

10.8

11.1

10.5

6.2

6.2

6.2

4.9

5.1

4.7

urban areas,by population size of place of residence, age, and sax: United Statas, 1966-70

Urbanized areas

Urban places

outside urbanized areas

Frequency, age, and sex

3 million 1-2.9 250,000 Less than 25,000 10,000- 2,500-

or more million 999,999 250,000 or more 24,999 9,999

250 Hertz

Both sexes 12-17 years .

Boys 12-17 years . . . . .

Girls 12-17 years . . . . .

Decibels re audiometric zero (ANSI-1969)

8.7

8.6

8.8

5.8

5.9

5.8

2.2

2.6

1.8

0.1

0.7

-0.5

4.2

5,8

2.8

7.8

9.4

6.4

12.4

13.6

11.3

7.4

8.0

6.8

5.0

5.2

4.6

11.0

11.1

11.0

6.6

6.7

6.4

1.9

2.2

1.6

3.1

4.1

2.2

6.2

7.6

4.8

9.0

9.B

8.1

10.6

12,6

8.8

7,6

7.8

7.5

6.0

6.6

5.6

8.6

8.6

8.6

5.9

6.6

5.2

2.0

3.0

1.0

2.0

2.6

1.4

5.2

6.8

3.8

7.0

8.0

6.0

9.5

11.9

7.3

5.8

6.2

5.2

5,6

6.3

4.9

10.6

10.6

10.8

7.1

7.3

6.8

2.8

3.0

2.6

2.4

2.8

2.0

5.6

6.6

4.4

9.5

10.7

8.2

13.7

16.4

10.6

7.0

8.5

5.4

6.0

6.4

5.7

9.9

10.4

9.4

6.0

6.6

5.4

1,5

2.0

1.0

1.1

1,5

0.8

5.4

7.1

3.8

9.0

11.0

7.2

11.8

14.0

9.8

7.4

8.7

6.4

5.0

5.6

4.6

I Average of hearing Iavels at 500, 1000, and 2000 Hertz.

72
Tabla 29. Maan hearing Iavels in decibels re audiometric zero (ANSI-I $%9) for the batter ear at cash test frequenoy and estimates for

speech among youths, by rate of population change in place of residence from 1950 to 1660 and age: United States. 1%6-70

Rate of population

change and age

Lass

12-17 years . . . . . .

12years . . . . . . . . .

13years . . . . . . ..m

14 years.,....,..

15years . . . . . . . . .

16years . . . .. o...

17years ..,......

Below*verage gain

12-17 years . . . . . .

12years . . . . . . . . .

13years, ... .o . . .

14years m...,....

15 years . . . . . . . . .

16 years . . . . . . . . .

17years. .m . . . . . .

Average gain

12-17 years . . . . . .

12yaars . . . . . . . . .

13years .,.......

14yaars .,.......

15 years . . . . . . . . .

16years . . . . . . . . .

17 years . . . . . . . . .

Above-average gain

12-17 years . . . . . .

12 years . . . . . . . . .

13years . . . . . . . . .

14years, . . . . . . . .

15years .,,......

16 years . . . . . . . . .

17 years . . . . . . . . .

Hertz

250 500 1000 2000 3000 4000 6000 8000 Speech’

Decibels ra eudiomatric zaro (ANSI-I 969)

8.9

9.2

9.0

8.8

8.7

I 9.2

8.6

9.1

9.2

9.5

8.9

9.4

8.8

8.8

10.6

10.4

11.0

10.2

10.4

10.8

11.2

8.0

8.1

8.3

7.3

7.8

7.6

9.3

6.4

7.4

6.5

6.6

6.4

6.2

5.4

5.8

6.4

6.0

5,7

6.2

5,4

5.4

6.2

6.2

6.5

5.8

6.6

6.0

6.0

5.2

5.6

5.6

5.4

5.0

4.7

5.1

1.7

2.0

1.6

1.8

1.6

2.2

1.2

1.7

2.5

1.6

2.0

1.6

1.3

1.3

2.0

1.8

2.7

1.4

1.6

2.1

1.8

1.0

1.5

1.0

1.2

1.2

0.5

0.8

1.2

0.8

1.1

1.6

1.2

1.6

0.6

1.8

2.4

2.2

1.6

2.0

1.1

1.6

0.8

0.2

0.4

0.8

0.8

1.4

1.6

0.6

1.0

0.9

0.4

1.0

0.2

0.0

6.0

5.4

5.7

6.3

6.1

6.8

5.4

5.2

6.0

5.6

4.8

5.4

4.2

4.6

5.6

5.2

5.6

5.3

5.9

5.8

5.8

4.8

4.5

5.2

4.6

4.9

4.4

4.6

8.3

7.6

7.8

8.4

8.6

9.4

8.1

7’.8

8.4

8.8

7.9

7.2

6.6

8.2

9.0

8.9

8.8

8.5

9.0

9.4

9.3

7.0

6.8

8.1

6.2

7.4

6.6

6.8

11.9

10.6

11.4

11.7

13.0

13.7

11.5

11.4

11.1

12.0

11.1

11.4

11.2

11.9

10.9

10.6

10.2

10.5

11.1

11.6

11.8

10.4

8.8

10.4

10.4

10.2

12.2

10.6

8.0

8.4

7.6

8.2

8.6

8.6

6.9

6.3

6.8

7.5

6.0

6.4

5.6

5.6

7.8

8.2

7.9

7.6

8.4

6.9

8.2

4.9

4.6

6.0

4.6

4.6

4.4

5.2

5.3

5.6

5.4

5.4

5.3

5.4

4.7

5.4

6.0

5.4

5.4

5.4

4.8

5.0

5.2

5.0

5.4

5,1

5.4

5.3

5.2

4.4

5.0

4.6

4.6

4.6

3.8

4.2

1Average of hearinglevelsat 500, 7000, and 2000 Hertz.

73
Table 30. Mean hearing levels in decibels re audiometric zero (ANSI-1969) for the battar ear at each tast fraquerrcy ●nd estimates for

speech among youths by ~ d family incoma, age, and sax: United States, 1968-70

Frequency, age, and sex

250 Hertz

Bothsexes 12-17 years . . . . . . . . . . . . . .

Boys12-17years . . . . . . . . . . . . . . . . . .

Girls 12-17 years . . . . . . . . . . . . . . . . . .

500 Hertz

Bothsexes 12-17 years . . . . . . . . . . . . . .

Boys 12-17 years . . . . . . . . . . . . . . . . . .

Girls 12-17 years . . . . . . . . . . . . . . . . . .

1000 Hertz

Bothsexes 12-17 years . . . . . . . . . . . . . .

Boys12-17 years . . . . . . . . . . . . . . . . . .

Girls 12-17 years . . . . . . . . . . . . . . . . . .

2000 Hertz

Bothsexes 12-17 years . . . . . . . . . . . . . .

Boys12-17 years . . . . . . . . . . . . . . . . . .

Girls 12-17 years . . . . . . . . . . . . . . . . . .

3000 Hertz

Bothsexes 12-17 years . . . . . . . . . . . . . .

Boys12-17 years . . . . . . . . . . . . . . . . . .

Girls 12-17 years . . . . . . . . . . . . . . . . . .

4000 Hertz

Bothsexes 12-17 years . . . . . . . . . . . . . .

Boys12-17 years . . . . . . . . . . . . . . . . . .

Girls 12-17 years . . . . . . . . . . . . . . . . . .

6000 Hertz

Bothsexes 12-17 years . . . . . . . . . . . . . .

Boys12-17 years . . . . . . . . . . . . . . . . . .

Girls 12-17 years . . . . . . . . . . . . . . . . . .

8000 Hertz

Bothsexes 12-17 years . . . . . . . . . . . . . .

Boys12-17years . . . . . . . . . . . . . . . . . .

Girk12-17years . . . . . . . . . . . . . . . . . .

Speech’

Bothsexes 12-17 years . . . . . . . . . . . . . .

Boys12-17 years . . . . . . . . . . . . . . . . . .

Girls 12-17 years . . . . . . . . . . . . . . . . . .

Family income

Less then $3,000- $5,000- !S7,000- $1o,ooo- $15,000

$3,000 $4,999 $6,999 $9,999 $14,999 or more

Decibels re audiometric zero (ANSI-1869)

10,0

10.0

10.0

7.0

6.7

7.2

3,1

3.5

2.8

2.6

3.1

2.2

7.3

8,4

6.2

9.9

11.6

8.4

12.2

14,2

10.6

8,4

9.4

7.6

6.4

6.6

6.2

9.8

9.4

10.2

6,9

6.9

6.9

2.6

2.5

2.8

1.9

2.5

1.4

6.6

7.8

5.4

9,2

10.5

7.9

11.8

13.4

10.2

7.8

8.8

6.8

6.1

6.2

5,9

9.0

8.9

9.0

6.0

6.4

5.6

1.6

2.2

1.1

1.0

1.6

0.5

5.2

6.8

3.7

8.0

9.4

6.6

11.1

13.0

9.2

6.6

7.4

5.8

5.1

5.5

4.7

9.1

9.2

9.0

5,8

6.0

5.6

1,6

1.9

1.2

0.8

1.2

0.3

4.9

6.0

3.6

7.6

8.7

6,4

10,9

12.2

9.5

6,6

7.3

5.8

5.0

5.3

4.5

8.7

8.6

8.8

5.1

5.4

4.9

0.8

1.0

0.6

0.4

0.7

0.2

4.4

5.6

3.2

6.8

7.8

5.9

10.4

11.6

9.2

6.0

6.4

5.5

4.3

4.5

4.1

8.8

9,0

8.6

5,0

5.6

4.2

0.2

0.3

0.0

0,1

0.4

-0.3

4.1

4.8

3.4

6.4

7.0

5.8

11,0

12.0

9.8

5.2

5.3

5.0

3.9

4,2

3,5
Table 31. Mean hearing Ievals in deckwls re audiometric zero (ANSI-I 969) for the batter ear at each test frequency and estimates for

speech among youths, by education of parent, age, and sex: United States, 1966-70

Years of schooling completed

Frequency, age, and sex

250 Hertz

Bothsexes 12-17 years . . . . . . . . . . . . .

Boys12-17 years . . . . . . . . . . . . . . . . . .

Girls 12-17 years . . . . . . . . . . . . . . . . . .

500 Hertz

Bothsexes 12-17 years . . . . . . . . . . . . .

Boys12-17 years . . . . . . . . . . . . . . . . . .

Girls 12-17 years . . . . . . . . . . . . . . . . . .

1000 Hertz

Bothsexes 12-17 years . . . . . . . . . . . . .

Bws12-17 years . . . . . . . . . . . . . . . . . .

Girls 12-17 years . . . . . . . . . . . . . . . . . .

2000 Hertz

Bothsexes 12-17 years . . . . . . . . . . . . .

Bws12-17year s . . . . . . . . . . . . . . . . .

Girls 12-17 years . . . . . . . . . . . . . . . . . .

3000 Hertz

Bothsexes 12-17 years . . . . . . . . . . . . .

Bws12-17year s . . . . . . . . . . . . . . . . .

Girls 12-17 years . . . . . . . . . . . . . . . . . .

4000 Hertz

Bothsexes 12-17 years . . . . . . . . . . . . .

Boys12-17vears . . . . . . . . . . . . . . . . . .

Girls 12-17 vears . . . . . . . . . . . . . . . . . .

6000 Hertz

Bothsexes 12-17 years . . . . . . . . . . . . .

Boys12-17 years . . . . . . . . . . . . . . . . . .

Gkls12-17vears . . . . . . . . . . . . . . . . . .

8000 Hertz

Bothsexes 12-17 years . . . . . . . . . . . . .

Bw12-17ve ads.. . . . . . . . . . . . . . . . .

Girls 12-17 years, . . . . . . . . . . . . . . . . .

10.1

9.8

10.4

7.6

7.2

8.0

3.7

3.7

3.7

2.9

3.5

2.4

8.0

9.6

6.4

10.4

12.2

8.6

12.7

15.0

10.6

9.1

10.8

7.6

9.2

9.2

9.2

7.0

7.4

6.8

2.6

3.4

1.9

1.8

2.6

1.1

6.9

8.2

5.6

9.0

10.6

7.2

12.0

13.8

10.0

8.1

9.6

6.6

9-11 12 13-15 16 17 or more

Decibels re audiometric zero (ANSI-1969)

9.4

9.2

9.8

5.9

5.7

6.1

1.5

1.5

1.5

1.2

0.9

1.4

5,2

6.0

4.4

8.3

9.3

7.4

11.5

13,2

9.8

7.2

7.6

6.9

9.4

9.3

9.4

6.4

6.6

6,2

2.3

2.4

2.1

1.8

2.4

1.2

5,8

7.0

4.6

8.5

10.0

7.0

11.4

12.8

9.9

7.2

8.4

6.1

9.0

9.0

9.0

5,6

5.8

5.3

1.2

1.6

0.8

0.8

1,4

0,2

4,8

6.2

3.3

7.6

8.4

6.6

11.0

12.2

9,6

6.4

7.0

5.7

9.0

9.0

9.0

5.1

5.3

4.9

0.6

0.6

0.6

0.0

0.4

-0.4

4.0

4.8

3.2

6.8

7.6

6.0

9.8

10.5

9.1

4.9

5.0

4.8

8.4

8.7

8.1

4.6

5.2

4.2

0.0

1.0

-0.8

-0.2

0.5

-0.8

4.5

6.2

3.0

7.0

8.6

5.6

10.6

12.0

9.3

6,3

7.0

5.6

8.4

8.2

8.6

4.8

5.7

3.6

0.4

0.2

0.6

-0.4

-0.4

-0.3

3.6

4.0

2.8

6.4

7.4

5.1

10.3

12.1

7.8

4.1

4.8

3.2

75
APPENDIX I

STATISTICAL NOTES

The Survey ”Design

The sample design for the first three programs

or Cycles I-III of the Health Examination Survey

has been essentially similar in that each has been

a multistage, stratified probability sample of

clusters of households in land-based segments.

The successive elements for this sample design are

primary sampling units, census enumeration district, segment (a cluster of households), eligible

persons, and finally the sample person.

The 40 sample areas and the segments utilized

in the design of Cycle III were the same as those

in Cycle II. Previous reports describe in detail

the sample design used for Cycle II and in addition

discuss the problems and considerations given to

other types of sampling frames, cluster versus

random sampling, and whether or not to control

the selection of siblings.4~6

Requirements and limitations placed on the

design for Cycle III, similar to-those for children

in Cycle II, were that:

1.

2.

The target population be defined as the

civilian noninstitutionalized population of

the United States, including Alaska and

Hawaii, between the ages of 12 and 17

years for Cycle III, with the special exclusion of children residing on reservation

lands of the American Indians because of

operational problems encountered on these

lands in Cycle I.

The time period of data collection be

limited to about 3 years for each cycle and

3.

4.

5.

the length of the individual examination

within the specially constructed mobile

examination center be between 2 and 3

hours.

Ancillary data be collected on specially

designed household, medical history, and

school questionnaires and from birth certificate copies.

Examination objectives be related primarily

to factors of physical and intellectual

growth and development.

The sample be sufficiently large to yield

reliable findings within broad geographic

regions and population density groups as

well as age, sex, and limited socioeconomic

groups for the total sample.

The sample was drawn jointly with the Bureau

of the Census starting with the 1960 decennial

census list of addresses and the nearly 1,900

primary sampling units (PSU’S) into which the

entire United States was divided. Each PSU is

either a standard metropolitan statistical area

(SMSA), a county, or a group of two or three

contiguous counties. These PSU’S were grouped

into 40 strata, each stratum having an average

size of about 4.5 million persons, in such a manner as to maximize the degree of homogeneity

within strata with regard to the population size

of the PSU’S, degree of urbanization, geographic

proximity, and degree of industridlzation. The

40 strata were then classified into four broad

geographic regions of 10 strata each and were

then, within each region, cross-classified by four

76
populati& density classes and classes of rate of

population change from 1950 to 1960. Using

a modified Goodman-Kish controlled-selection

technique, one PSU was drawn from each of the

40 strata.

Further stages of sampling within PSU’S required first the selection of census enumeration

districts (ED’s). The ED’s are small well-defined

areas of about 250 housing units into which the

entire Nation was divided for the 1960 population

census. Each ED was assigned a “measure of

size” equal to the rounded whole number resulting from a “division by nine” of the number of

children aged 5-9 in the ED at the time of the

1960 census. A sample of 20 ED’s in the sample

PSU were selected b-y systematic sampling, each

ED having a probability of selection proportional

to the population of children 5-9 years at the

time of the 1960 census date. A further random

selection by siiie of segments (smaller clusters of

housing units) within each ED was then made.

Because of the 3-year time interval between

Cycle II and Cycle III, the Cycle HI frame had

to be supplemented for new construction and to

compensate for segments where housing was

partially or totally demolished to make room for

highway construction or urban redevelopment.

Advanced planning for the examinations at

the various locations or stands provided for about

17 days of examinations which limited the number of examinees per Iocath to approximately

200. When the number of eligible youths in the

sample drawn for a particular location exceeded

this number, subsampling was done by deleting

from the master list of eligible youths (ordered

by segment, household orde~ wi~in segment, and

age within household) every nth name on the list

starting with the y th name, y being a number

between 1 and n selected randomly and n being

the extent of oversampling in the original draw.

In Cycle 111, as in Cycle 11, twins who were

deleted in the sample selection, were also scheduled for examination, time permitting, as were

youths deleted from the Cycle III sample who

had been examined in Cycle IL The sample was

selected in Cycle III, as it has been for the children in Cycle”II, so as to contain the correct proportion of youths from families having only one

eligible youth, two eligible youths, Wd so on to

be representative of the total target population.

However, since households were one of the elements in the sample frame, the number of related

youths in the resultant sample is greater than

would come from a design which sampled youths

12-17 years without regard to household. The

resultant estimated mean measurements or rates

should be unbiased, but their sampling variability

will be somewhat greater than those from more

costly, time-consuming systematic sample designs

in which every kth youth would be selected.

The total probability sample for Cycle III included 7,514 youths representative of the approximately 22.7 million noninstitutionalized United

States youths of 12-17 years. The sample contained youths from 25 different States and

approximately 1,000 in each single year of age.

Tile response rate in Cycle Id was 90 percent,

with 6,768 youths examined out- of the total

sample. These exarninees were closely representative of those in the sample as well as the population from which the sample were drawn with

respect to age, sex, race, region, popula’tion

density, and population growth in area of residence. Hence it appears unlikeIy that nonresponse could bias the findings appreciably.

Measure used to controI the quaKty of the

data from these surveys have been cited prcviously;G, Z4 those additional measures specifically related to the testing of hearing are

outlined in an earlier section of this report.

Reliability

While measurement processes in the surveys

were carefully standardized and closely controlled, the correspondence between the real

world and survey results cannot be expected to be

exact. Survey data are imperfect for three major

reasons: (1) results are subject to sampling error,

(2) the actual conduct of a survey never agrees

perfectly with the design, and (3) the measurement processes themselves are inexact even

though standardized and controlled.

The fiist report on Cycle 1116 describes in detail the faithfulness with which the sampling

design was carried out.

77
Data recorded for each sample youth ar~’

inflated in the estimation process to characterize

the larger universe of which the sample youth i:

representative. The weights used in this inflatio]l

~)rCJCess are a product of the reciprocal of the

pr:hability of selecting the youth, an adjustment

for nonresponse cases, and a poststratified ratio

adjustment which increases precision by bringing

survey results into cIoser alignment with known

United States population figure by color and sex

within single years of age 12 through 17 for the

~tlllili”; survty.

In the third cycle of the Health Examination

Survey (as for the children in Cycle H) the samples were the results of three principal stages of

selection—the single PSU from each stratum, the

20 segments from each sample PSU, and the sample youth from the eIigible persons. The probability of selecting an individual youth is the

product of the probability of selection at each

s~dge.

Since the strata are roughly equal in population size and a nearly equal number of sample

youths were examined in each of the sample

PSU’S, the sample design is essentially selfwieghting with respect of the target population;

that is, each youth 12 through 17 years had

about the same probability of being drawn into

the respective samples.

The adjustment upward for nonresponse is

intended to minimize the impact of nonresponse

on final estimates by imputing to nonrespondents

the characteristics of “similar” respondents.

Here “similar” respondents were judged to be

examined youths in a sample PSU having the

same age (in years) and sex as youths not examined in that sample PSU.

The poststratified ratio adjustment used in the

third cycle achieved most of the gains in precision

which would have been attained if the sample

had been drawn from a population stratified by

age, color, and sex and makes the final sarnplc

estimates of population agree exactly with independent controls prepared by the Bureau of

the Census for the United States noninstitutionJlzed population as of March 9, 1968 (approximate midsurvey point for Cycle III), by color

and sex for each single year of age 12-17. The

sampling weight of every responding sample

youth in each of the 24 age, color, and sex classes

is adjusted upwards or downwards so that the

weighted total within the class equals the independent population control for each survey.

In addition to youths not examined at all,

there were some whose examinations were incomplete in one frequency or another. If the technician considered some parts of the test unreliable

Table I . Missing hearing test data, by age of examinee: Health Examimtiorr Survey, 1886-69

——. —.—.

Hearing test missing

All frequencies (number of youths

for whom one or mom test parts

are incomplete) . . . . . . . . . . .

Test incomplete for frequencies of:

250 Hertz . . . . . . . . . . . . . .

500 Hertz . . . . . . . . . . . . . .

IfMOHertz . . . . . . . . . . . . . .

2000 Hertz . . . . . . . . . . . . . .

3000 Hertz . . . . . . . . . . . . . .

4000 Hertz . . . . . . . . . . . . . .

6000 Hertz . . . . . . . . . . . . . .

8000 Hertz . . . . . . . . . . . . . .

All

exeminees, 12 13

12-17 yeers years

years

3811 71 8

45

45

46

46

47

48

46

52

14 15 16 17

years years years years

Numbar of ears

I

7

L

10

8 8

8 8

8 8

8 11

9 10

7 10

9 12

5

5

5

6

5

5

5

7

10

11

10

10

10

10

12

12

10

10

12

10

10

10

10

10

3

3

3

4

3

4

2

2

78
because of physical or mental reasons or t

audiometer was not functioning properly, the

test parts affected were also not used. The extent

of missing data for the hearing tests is shown in

table 1.

For each of the examined youths not given the

hearing test, a respondent of the same age~sex-race

group was selected at random and his test results

assigned to the nonexarnined person.

When only incomplete tes~ results were available (38 youths), a variety of methods were used,

depending upo]l the extent of missing data. If

only one ear was tested, it was assumed that the

findings for the other ear would have been the

same. If partial results were available, the levels ~

reached by the other ear at the particular frequencies were used as the estimates if they were

consistcmt with the au&o.Wam for the ear on

which data were missing. Otherwise, projections

were made on the basis of the parts of the

audiogram available.

Sampling and Measurement Error

In the present report, reference has been made

to efforts to minimize bias and variability of measurement techniques.

‘l’he probability design of the survey makes

possible the calculation of sampling errors. The

sampling error is used here to determine how

imprecise the survey test results may be because

they come from a sample rather than from the

mcwurcments of all elements in the universe.

The estimation of sampling errors for a study

of the type of the Health Examination Survey is

difficult for at least three reasons: (1) measurement error and “pure” sampling error are confounded in the data–it is not easy to find a

procedure which will either completely include

both or treat one or the other separately, (2) the

survey design and estimation procedure are complex and accordingly require computationally

involved techniques for the calculation of variances~ and (3) from the” survey are coming

thousands of statistics, many for subclasses of

the population for which there are a small number of cases. Estimates of sampling error are

obtained from the sample data and are themselves subject to sampling error which may be

large when the number of cases in a cefI is stnali

or even occasionally when the number of cases

is substantial.

Estimates of approximate sampling variability

for selected statistics used in this report are

included in the detailed tables. These estimates

have been prepared by a replication technique

which yields overaU variability through observation of variability among random subsamples of

the total sample.24 The method reflects both

“pure” sampling variance and a part of the measurement variance.

In accordance with usual practice, the interval

estimate for any statirtic may be considered the

range within one stanc!kird error of the tabulated

statistic, with 68-percent confidence, or the range

within two standard errors of the tabulated statistic, with 95-percent confidence. The latter is

used as the Ievel of significance in this report.

An approximation of the standard error of a

difference d = x - y of two statistics x and y is

given by the formula Sd = (S; + S; )1’2 where S.

and SY are the sampling errors, respectively of

x and y. Of course, where the two groups or

measures are positively or negatively correlated,

this will give an overestimate or underestimate,

respectively, of the actual standard error. These

estimates are shown in table IL

Small Numbers

In some tables magnitudes are shown for cells

for which the sample size is so small that the

sampling error may be several times as great as

the statistic itself. Obviously in such instances

the statistic has no meaning in itself except to

indicate that the true quantity is small. Such

numbers, if shown, have been included in the

belief that they may heIp to convey an impression of the overall story of the table.

79
TAle II. Standard errors of eatimatas for average hearing levels for speech (eatirnated)l and total number of examinees, by eekted chwcteriatia:

Unitad States,1966-70

Characteristic

Total number

of examinees

Race

White . . . . . . . . . .

Negro . . . . . . . . . .

Other races . . . . . .

Region

Northeast . . . . . . .

Midwest . . . . . . . .

South . . . . . . . . . .

West . . . . . . . . . .

Urban aree

3 million or more . . .

1-2.9 million . . . . .

250,000-999,999 . . .

Under 250,000 . . . .

25,000 or more . . . .

10,000-24,988 . . . .

2,500-9,998 . . . . . .

Rural area . . . . . . .

Income

Lass than $3,000. . .

$3,00C@4,999 . . . .

$5,000-$6,999 . . . .

$7,000-$9,999 . . . .

$10,000-$14,999 . . .

$15,000 or more . . .

Education of parent

Lass than 5 years . . .

5-7years . . . . . . .

8years . . . . . . . . .

%lly ears . . . . . . .

12years . . . . . . . .

13-15 years . . . . . .

16years . . . . . . . .

17 yearn or more . . .

Population change

Loss . . . . . . . . . .

Below-average gain . .

Average gain. . . . . .

Abova-ave:age gain . .

rotal number

of exami nees

. . . .

5,735

988

34

1,641

1,757

1,704

1,666

1,420

645

782

540

283

187

408

2,292

817

946

1,065

1,555

1,277

652

443

609

845

1,417

1,915

554

443

350

1,601

1,754

1,773

1,640

—

Both Boys Girls

Sexes

12-17 12-17 12 13 14 15 16 17 12-17 ‘ 12 13 14 15 16 77

years! years years years years yaars years years years years years years years years years

6,768 3,545 643 626 618 613 556 469 3,223 547 562 586 503 536 468

Standard error in dB re audiometric zaro (ISO-19EX)

0.15

0.25

0,65

0.20

0.25

0.30

0.45

0.25

0.45

0.60

0.90

0.85

1.00

0.25

0.20

0.25

0.35

0.20

0.15

0.20

0.15

0.50

0.50

0.25

0.20

.0.15

0.26

0.25

0.25

0.30

0.30

0.30

0.25

0.20

0.35

0.80

0.30

0.35

0.35

0.50

0.35

0.50

0.55

0.50

1.05

1.25

o.4a

o.3a

0.45

o.5a

o.3a

0.20

0.25

0.25

0.75

0.40

0.30

0.20

0.20

0.55

0.30

0.40

0.35

0.40

0.35

0.25

0,50

9.50

0.35

0.50

0.50

0.90

0.40

0.35

1.10

1.95

2.55

1.80

0.95

0.45

0.90

0.90

0,80

0.40

0.40

0.45

1.90

0.60

0.95

0.70

0.40

0.55

0.65

0.55

0.60

0.60

0.65

0.60

0.30 0.25

0.65 0.55

18.15 16.90

0.65 0.30

0.50 0.20

0.50 0.40

0.50 0.70

0.95 0.45

0.65 0.70

0.55 0.45

1.20 1.95

1.25 0.65

1.65 1.95

1.00 0.70

0.40 0.45

1.10 1.20

0.95 0.55

0.60 0.60

0.45 0.35

0.60 0.45

0.55 0.70

1.35 1.30

1.30 0.55

0.80 0.80

0,55 0.60

0.45 0.30

0.65 0.65

1.30 0.60

0.75 0.95

0,25 0.80

0.55 0.60

0.75 0.25

0.55 0.40

0.30 0,45

0.70 0.70

3.40 18.45

0.85 0.40 ~

0.35 0.55 i

0.25 1.35,

0.60 0.50

0.55 0.25

0.70 0.65

0.65 0.85

0.70 1.15

1.90 1.80

1.15 2.70

1.35 2.40

0.35 0.65

0.80 1.40

0.85 1.00

0.60 0.60

‘0.30 0.30

0.45 0.50

0.80 0.70

1.30 0.85

0.70 2.05

0.85 0.75

0.50 0.65

0.35 0.45

0.70 0.85

1.00 1.00

0.95. 0.60

0.65 1.60

0.40 0.50

0.30 0.30

0.50 0.35,

v

0.40 0.10 0.25 0.25 ().20

0.65 0.30 0.55 1.05 0.60

0.00 1.60 3.60 42.@ 42.40

0.70 0.25 0.30 0.20 0.35

0.75 0.20 0.35 0.60 0.30

0.65 0.35 0.55 0.60 0.65

0.90 0.40 0.70 rJ.55 0.35

0.45 0.15 0.35 0,65 0.35

1.50 0.45 0.85 1.10 0.80

1.10 0.90 1.60 1.50 1.20

5.00 1.45 1.05 2.40 2.25

0.95 0.65 2.05 1).go 0.75

2.45 0.75 1.05 2.35 11.65

0.40 0.20 1.00 0.50 1.20

0.45 0.20 0.35 0.45 0.40

1.30 0.30 0.90 I .25 1.00

0.70 0.30 ().50 ().55 0.55

0.65 0.20 ().40 o.65 0.60

0.95 0.20 0.50 O,a 0.35

0.55 0.20 0.45 0.75 0.40

0.75 0.25 0.65 0.75 0.85

1.05 0.50 1.95 1.60 1.00

1.25 O.m 0.75 0.75 1.85

0.60 0.25 0.40 0.45 0.40

0.55 0.20 0.45 0,60 (),45

0.80 0.20 0.50 0.40 0.45

0.80 0.30 0.75 f.q!j 0.55

1.10 0.20 0.45 0.70 0.95

0.65 0.35 1.20 1.30 1.00

0.70 0.25 0.25 0.55 0.55

0.80 0.40 0.75 0.65 0.45

1.10 0.30 0.35 0.75 0.45

0.80 0.15 0.55 O.m o.4a

0.20

0.60

7.15

0.50

0.65

0.20

0.30

0.35

0.75

0.90

2.oa

0.35

7.8a

o.4a

0.25

o.8a

o.6a

0.60

0.45

0.35

0.60

0.60

0.55

0,95

0.25

0.70

0.70

1,15

0.20

0.70

0.65

0.50

0.26

0.66

35.35

0.55

0.40

0.40

0.50

0.45

0.45

o.7a

1.2a

o.6a

I 1.7a

1.00

0.50

0.60

1.25

0.65

0.60

0.50

0.55

1.35

0.50

0.55

0.35

0.65

0.70

1.00

0.70

0.45

0.75

0.30

0.40

0.30

0.65

!6.40

0.60

0.30

0.55

0.50

0.36

0.45

0.65

1.85

1.10

?0.1o

0.50

0.45

0.80

0.80

0.40

0.45

0.50

0.65

2.60

0.75

0.90

0.50

0.45

0.60

0.65

0.95

0.60

0.65

0.30

0.35

1Averageof hearing Ieve]s at 500, 1000, and 2000 Hertz.

000
APPENDIX II

DEMOGRAPHIC AND SOCIOECONOMIC TERMS

Age.–The age recorded for each youth was the

age at last birthday on the date of examination.

The age criterion for inclusion in the sample used

in this survey was defined in terms of age at time

of interview. Since the examination usually took

place 2 to 4 weeks after the interview, some of

those who were 17 years old at the time of interview became 18 years old by the time of examination. There were 23 such cases. In the adjustment and weighting procedures used to produce

national estimates, these 23 were included in the

17 year group.

Race. –Race was recorded as “white,”

“Negro,” or “other.’> “Other” included American Indians, Chinese, Japanese, and all races other

than white or Negro. Mexican persons were

included with “white” unless definitely known

to be American Indian or of another race.

Negroes and persons of mixed Negro and other

parentage were recorded as “Negro.”

Geogaphic re@”on.–For purposes of stratification the United States was divided into four

geographic regions of approximately equal population. These regions, which correspond closely

to those used by the Bureau of the Census, were

as follows:

Re~on States Included

Northeast Maine, Vermont, New Hampshire, Massachusetts, Connecticut, Rhode Island, New York,

New Jersey, and Pennsylvania

Midwest Ohio, Illinois, Indiana, Michigan,

Wisconsin, Minnesota, Iowa, and

Missouri

South Delaware, Maryland, District of

Columbia, West Virginia, Virginia,

Kentucky, Tennessee, North Carolina, South Carolina, Georgia,

Florida, Alabama, Mississippi,

Louisiana, and Arkansas

West Washington, Oregon, California,

Nevada, New Mexico, Arizona,

Texas, Oklahoma, Kansas, Nebraska, North Dakota, South

Dakota, Idaho, Utah, Colorado,

Montana, Wyoming, Alaska, and

Hawaii

Urban-rural.–The definition of urban-rural

areas was the same as that used in the 1960

Census. According to this definition, the urban

population was comprised of all persons living in

(1) places of 2,500 inhabitants or more incorporated as cities, boroughs, villages, and towns

(except towns in New England, New York, and

Wisconsin); (2) the densely settled urban fringe,

whether incorporated or unincorporated, of

urbanized areas; (3) towns in New England and

townships in NewJersey and Pennsylvania which

contained no incorporated municipalities as subdivisions and had either 2,500 inhabitants or

more, or a population of 2,500 to 25,000 and a

density of 1,500 persons or more per square mile;

(4) counties in States other than the New England States, New Jersey, and Pennsylvania that

had no incorporated municipalities within their

boundaries and had a density of 1,500 persons

or more per square mile; and (5) unincorporated

places of 2,500 inhabitants or more not included

81
in any urban fringe. The remaining population

was classified as rural.

Urban areas are further classified by population size for places within urbanized areas and

other urban places outside urbanized areas.

Family income.–The income recorded was

the total income of the past 12 months received

by the head of the household and all other household members related to the head by blood,

marriage, or adoption. This income was the

gross cash income (excluding pay in kind) except

in the case of a family with their own farm “or

business, in which case net income was recorded.

Parent.–A parent was the natural parent or,

in the case of adoption, the legal parent of the

child.

Guardian.-A guardian was responsible for the

care and supervision of the child. He (or she)

did not have to be the legal guardian to be considered the guardian for this survey. A guardianship could only exist when the parent(s) of the

child did not reside within the sample household.

Head of household. –Ordy one person in each

household was designated as the “head.” He

(or she) was the person who was regarded as the

“head” by the members of the household. In

most cases the head was the chief breadwinner

of the family although this was not always true.

In some cases the head was the parent of the

chief earner, or the only adult member of the

household.

000

82
APPENDIX Ill

RECORDING FORM

HEALTH EXAMINATION SURVEY–III

AuD!oM51XR NO. (6.9) -

USE THIS SECTION WHEN

SAMPLE NO. IS EVEN

c~

4000:

1000:

6000:

500:

2000,

250:

4000:

8000:

‘ccl’ +

‘CIrl’

‘n’

‘b’

‘d’

‘h’ +

I I I

CONDITIONS AFFECTING 1SS1 RESULT5 (Ckk)

(4J) “ o ❑ NONE

XAMINER (10-11)

CARD

COL. NOS.

(1 2-15]

(16-19)

[20-23)

(24-27)

(28-31)

(32-35]

(36-s9]

(w-u)

(44-47)

USE THIS SECTION WHEN

SAMPLE NO. IS ODD

CA

4000:

1000:

6000:

500:

250:

4000:

3000:

‘m’

‘n’

‘b’

‘l=&l’

‘b’

‘d’

‘n’

‘Cr3’

‘b’

CONDITIONS AFFECTING TEST RESULTS

1 ❑ Cold at present 4 ❑ Cold within past week

2 ❑ Ear discharge 5 ❑ Eamche within past week

3 c Equipment defective” 6 ❑ Sehavior- 7 ❑ Other”

● Specify frequency (CPS.J if only cetiwin one(s) affected, and describe:

PNS-4611-2 , SAMPLE No. [1-5)

REV. II -66

/

—000

83
APPENDIX IV

STANDARDS FOR REFERENCE (AUDIOMETRIC) ZERO

The sound pressure standards for “normal”

auditory threshold-the 1951 American Standards Association audiometric zero—maintained

by the National Bureau of Standards were

derived from data of the National Health Survey

of 1935-36, as described previously. The original

measurements were determinations of voltages

applied at the terminals of the audiometer earphones used in the survey for a subgroup of persons with “normal” hearing. These threshold

data were transferred by loudness balancing to a

group of standard earphones designed especially

for stability in calibration-the Western Electric

705-A. After loudness balancing, the earphones

were placed on an NBS 9-A standard calibrating

coupler and their response was measured.

Later, and in a similar fashion, the National

Bureau of Standards transferred the threshold

from the Western Electric 705-A earphone to

five other types of earphones.

The threshold standards in terms of sound

pressure in a standard coupler will be valid for

the earphones of these types provided the earphone cushions are of controlled profiie, thickness, and compliance; the distance from the front

of the face of the moving diaphragm to the plane

of the cushion is held constant; and that the

earphone is held against the ear with a constant

coupling force. 13,23 They will not apply to

earphones of other types.

The transfer characteristics for the TDH-39

earphones hIX-41/AR cushions ‘used in this survey were those determined for the Health Examination Survey instruments at the University of

Pittsburgh to replace those previously suggested

by Allison Laboratories.z 5

The new (1964) standard reference zero recommended by the International Organization

for Standardization (lSO)l 0~2G-29 was adopted

in the 1969 American National Standard for

audiometers during conduct of this survey to

replace the differing 1951 American and the

1954 British Standards.30 Since these new

standards are appearing in many of the journals

and other technical publications, the comparison

of them with the 1951 American Standard on

the 705-A earphones and the TDH-39 earphones

used in this survey is shown in table III.

The thresholds for the 1951 American Standard and the recommended 1S0 Standard on the

705-A earphones are rounded to the nearest

0.5 dB in accordance with the 1S0 method of

presentation. The TDH-39 thresholds are retained in the form used to convert the findings

from this survey to decibels re 0.0002 dyne per

square centimeter, as shown in the section “Comparison With Previous Findings.”

Table III. Comparison of 1951 Amerisan Standard and the

recommended ISO Standard for referenca zero

1951 American Standard Recommended ISCI

for reference zero of: Standard for

Frequency reference zero

WE-705-A TDH-39 of WE-705-A

earphones’ earphones’ earphones’

Decibels re 0.0002 dynes per square cm.

250 CpS . . . 39.6 45.4 24.5

500Cps . . . 25.0 30.0 11.0

looocps . . . 16.5 22.6 6.5

mocps . . . 17.0 21.8 8.5

3000 Cps . . . 216.0 26.7 7.5

4000 Cps . . . 15.0 16.9 9.0

8000 Cps . . . % 7,5 23.9 8.0

8000 Cps . . . 20.9 26.5 9.5

1on N ~ 9.A coupler. TDH-39 eerphone reference values

shown here are those determined for the Health Examination

Survey instruments at the University of Pittsburgh~4 The

other two sets were determined by averaging many diffarent determinations from many different countrias, available from the

National Bureau of Standards.

2Estimated.

84 000
—

Series 1.

Series 2.

Series 3.

Series 4.

Series 10.

Series 11.

Series 12.

Series 13.

Series 14.

Series 20.

Series 21.

Series 22.

OUTLINE OF REPORT SERIES FOR VITAL AND HEALTH STATISTICS

Orighdy Public Health Service Fkblication No. 1000

Programs and collection procedtbres.— Reports which describe the general programs of the National

Center for Health Statistics and its offices and divisions, data collection methods used, definitions,

and other material necessary for understanding the data.

Data evacuation and methods research. —Studies of new statistical methodology including: experimental tests of new survey methods, studies of vital statistics collection methods, new analytical

techniques, objective evaluations of reliability of collected data, contributions to statistical theory.

Anatyticaf studies. —Reports presenting analytical or interpretive studies based on vital and health

statistics, carrying the analysis further than the expository types of reports in the other series. /

Documents and committee reports. — Final reports of major committees concerned with vital and

health statistics, and documents such as recommended model vital registration laws and revised birth

and death certificates.

Data from &e Health Interview Survey. —Statistics on illness, accidental injuries, disability, use of

hospital, medical, dental, and other services, and other health-related topics, based on data collected

in a continuing national household interview survey.

Data from the Health Examination Survey. —Data from direct examination. testing, arrd measurement of national samples of the population provide the basis for two types of reports: (1) estimates

of the medically defined prevalence of specific diseases in the United States and the distributions of

the population with reqpect to physical, physiological, and psychological characteristic; and (2)

amt 1ys is of relationships among the various measurements without reference to an explicit finite

universe of persons.

Data from the Institutional Population Survey s.- Statistics relating to ‘tie health characteristics of

persons in institutions, and on medical, nursing, and personal care received, based on national

samples of establishments providing these services and samples of the residents or patients.

Data from the Hospital Discharge Survey. —Statistics relating to discharged patients in short-stay

hospitals, based on a sample of patient records in a national sanlPle of hospitals.

DOta on health resources: manpower and facilities. —Statistics on the numbers, geographic distribution, and characteristics of health resources including physicians, dentists, nurses, other health

manpower occupations, hospitals, nursinfz homes, and outpatient and other inpatient facilities.

Data on mortality.— Various statistics on mortality other than as included in annual or monthly

reports— special analyses by cause of death, age, and other demographic variables, also geographic

and time series analyses.

Data on natality, marriage, and divorce. —Various statistics on natality, marriage, and divorce other

than as included in annual or monthly reports— special analyses by demographic variables, also

geographic and time series analyses, studies of fertility.

Data from the National Nata&ity and Mortality Surveys. —Statistics on characteristics of births and

deaths not available from the vital records, based on sample surveys stemming from these records,

including such topics as mortality by socioeconomic class, medical experience in the last year of

life, characteristics of pregnancy, etc.

F,or a list of titles of reports published in these series, write to: Office of Information

National Center for Health Statistics

Public Health Se~ice, HRA

Rockville, Md 20852
U.S. DEPARTMENT OF

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