DATA EVALUATION AND METHODS RESEARCH

Development of the

Speech Reception Test

Description of the development for use in the Health and Nutrition

Examination Survey of 1974-75 of a new test of hearing discrimination ability for speech sounds based on the revised Central Institute for the Deaf Sentences devised by a working group of the

Committee on Hearing and Bioacoustics of the National Research

Council.

DHEW Publication No. (HRA) 78-1345

Series 2

Number 71

US. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE

Public Health Service

Health Resources Administration

Hyattsville, Md. October 1977
Library of Congress Cataloging in Publication Data 

Elkins, Earleen. 

Development of the speech reception test. 

(Vital and health statistics: Series 2, Data evaluation and methods research; no. 71) 

(DHEW publication; no. (HRA) 781345) 

Bibliography: p. 

1. Audiometry, Speech. I. Causey, G. Donald, joint author. II. Roberts, Jean, joint author. 

III. Title. IV. Series: United States. National Center for Health Statistics. Vital and health 

statistics: Series 2, Data evaluation and methods research; no. 71. V. Series: United States. 

Dept. of Health, Education, and Welfare. DHEW publication; no. (HRA) 78-1345. [DNLM: 

1. Hearing tests. 2. Hearing disorders-Diagnosis. W2 A N148vb no. 711 

RA409.u45 no. 71 [RF294.5.S6] 312.‘07’23s 

ISBN o-84060088-7 [617.8‘9] 77-2800 

For sale by tho Superintendent of Documents, U.S. Government Printing Offhx 

Washington, D.C. 20402 

Stock No. 017-02240589-l 
NATIONAL CENTER FOR HEALTH STATISTICS

DOROTHY P. RICE, Director

ROBERT A. ISRAEL, Deputy Director

JACOB J. FELDMAN, Ph.D., Associate Director for Analysis

GAU F. FISHE~ Associafe Director for the Cooperative Health Stat fitics System

ELIJAH L. WI-DTE,Associate Director for Data Systems

JAMES T. BAIRD, JR., Ph.D., Associate Director for International Statistics

ROBERT C. HUBER, Assoctite Director for Mawgement

MONROE G. SIRKEN, Ph.D., Assoa”ate Director for Mathematical Statistics

PETER L. HURLEY, Assoctite Directorfor Operations

JAMES M. ROBEY, Ph.D., Assoctite Director for Program Development

PAUL E. LEAVERTON, PhJ1., Associate Director for Research

ALICE HAYWOOD, Information Ofiicer

DIVISION OF HEALTH EXAMINATION STATISTICS

ARTHUR J. McDOWELL, Director

JEAN-PIHULE H&BICHT, M.D., Ph.D., Special Assistant to Director

JEAN ROBERTS, Chtif Medical Statistics ~rtmch

ROBERT S. MURPHY, Chief Survey Planning and Development Branch

COOPERATION OF THE U.S. BUREAU OF THE CENSLE

Under the legislation establishing the National HeaIth Survey, the Public Health Service is

authorized to use, insoh as possible, the m-vias or fzcilitics of other l?edcral, State, or private

agenacs.

h acmrdamcc with specifications ~tablished by the Division of Health Interview Statistics,

the Bureau of the Census, under a conhaeturd arrimgcmentj pm-dtipate d in plauning tbe survey

and colkcling the data.

Vital and Health Statistics-Series 2-No. 71

DH EW Publication No. (H RA) 78-1345

Library of tingrecs Catakg Card Number 77-2800
CONTENTS

Introduction .....................................................................................................................................................

Wc&omd ........................................................................................................................................................

Development of Test Mttids . ............. ........... ...... ....................... .. ............ .......... ............................... ....... .......

Dmcription of Stiti ...................................................m..............................m...............................................

Tdkm ..... .....................................................................................................................................................

Recording Eqtipmcnt ...................................................................................................................................

Tape Assembly Rocedwes ............................................................................................................................

Verification of Stitdi ................................................................................................................................. ..

Quality of Recording ................................................................................................................................ ....

Pilot Study ...... ..................................................................................................................................................

Study Among Normsl-Hearing Subje~s .............................................. ..............................................................

Subjects and Metiod .................................................................................................... ...............................

Ftid~ ........................................................................................................................................................

Study Among Sensorineursl-Hearing-Impaired Subjetis .....................................................................................

Subjeti ........................................................................................................................................................

Mefiod .................................................................... ....................................................................................

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

Intcrht Equivalency Smdy ................................................................................................................................

Subject~ ............ ...........................................................................................................................................

Metiod . ....................... ........... .............. ...................... .. .... ........ ...................... ............ ..................................

FindirsgI................................................................................................................................................ ........

Discussion .................................................................................................................................... ......................

Normal U ............ ................................................................................... ...........................................

Hearing Impaired ........... ....................................................................................................................... .......

Intcrlist Eqtivden~ ............................... ..... ...............................................................................................

s~ ...........................................................................................................................................................

References ................................................................................................................................... ......................

1

1

2

2

2

2

4

4

4

5

5

5

6

7

7

9

9

10

10

10

10

11

11

12

12

12

13

Appendm. Hearing Characteristics of the Sensorineural Hearing-Impaired Subjects in the Study ...................... 16

LIST OF FIGURES

1-1. schematic diagram of recording equipment and its placement ................................................................ 3

1-2. Diagram of talker, examiner, snd microphones in recording &mber ..................................................... 3

2. Performance-intensity functions derived horn mean discrimination scores on tbe RCID Sentence Grits

by 100 norsnahhcaring snd 55 impskcd-hearing mbjetis ........................................................................ 6

...

Ill
LIST OF TEXT TABLES

1. Mean, standard deviation, and standard error of the mean obtained with 10 lists of RCID Sentences

from 100 normid-hearing subjects at 8 presentation levels ....................................................................... 6

2. Pearson correlation coefficient from 100 normal-hearing subjects’ scores on 10 lists of RCID Sentences

at 8 presentation levels ............................................................................................................................ 7

3. Mean, standard deviation, and standard error of the mean obtained on each of 10 lists of RCID Sentences from 10 normal-heming subjects at 8 presentation levels ............................ .............. ...... .............. 8

4. Mean, standard deviation, and standard error of the mean obtained with 10 lists of KID Sentences at

12 sensation levels for the 55 subjects with sensorineural hearing impairments, and the number contributing to each mean ........................................................................................................................... 9

5. Mean, standard deviation, and standard error of the mean obtained on RCID Sentence lists by 10 subjects at 10 dB SL and 10 subjects at 20 dB SL, and by both groups combined .... . .. ... . . .. ... . .. ... . ..... . .. ... . .. 11

SYMBOLS

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

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

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

Quantity more than O but less than 0.05---- 0.0

Figure does not meet standards of

reliability or precision ------------------------

*

iv
DEVELOPMENT OF THE SPEECH RECEPTION TEST

EarIecn Elkins, Ph.D., and G. Donald Causey, Ph.D., University of Maryland, and

Jean Roberts, Dizuk_onof Health Examination Statistics, NCHS

INTRODUCTION

The hearing component of the Health and

Nutrition Examination Survey in 1974-75 was

designed to obtain data on the discrimination

ability for speech sounds and the relationship of

this ability to pure-tone air-conduction hearing

thresholds among adults. These data, which will

have been obtained for the first time with standardized methods on a national probability sample of civilian noninstitutionalized adults 25-74

years of age in the United States, will make it

possible to assess objectively the functional implications of hearing impairment in the adult

population. Prior to the start of the Heakh and

Nutrition Examination Survey there was general

agreement that one or more measures empIoying

speech stimuli are necessary to quantify an individual’s abiIity to understand suprathreshoId

speech.1 Recent research has shown the extent

to which specific types of hearing loss affect the

intelligibility of speech and tlhat amplification

(such as with hearing aids) does not restore full

discrimination when there is sensorineural IOSS.2

T& new speech reception test provides an

objective instrument, not previously avaiIable,

for the determination within a short period of

time of the abiIity of adults to hear and understand everyday conversational speech. This developmental study further provides some indication of the limitation and precision of this type

of survey measurement in comparison with

Ionger clinical tests of speech discrimination.

BACKGROUND

The d hoc advisory committee for the hearing component of the examination had recommended for use in speech discrimination testing

the Revised Central Institute for the Deaf

(RCID) Sentences, that had been developed by a

working group of the Committee on Heming and

Bioacoustics (CI-L4BA) of the National Research

CouneiI. The R(XD Sentences, while not yet on

a suitable recording, were recommended as providing a better indication of functional hearing

impairment within the time limits available for

this component of the examination than was

posslMe with the test material commercially

available.

Recorded materiak for speech discrimination testig, then commercially availabIe, consisted of lists of 50 monosyllabic words. Those

deveIoped at the Harvard Psychoacoustic Laboratory, known as PB-50 lists,3 were compiled

with strict adherence to phonetic composition.

Later, Hirsh and his associates at the Central Institute for the Deaf4 recorded four 5O-word lists

compiled with primary emphasis on a restricted

range of word famdkity. These recordings are

known as the l\~-22 lists. A considerakde number

of research projects have empIoyed these two

recordings and speech discrimination ability has

been clinically assessed with them. No test or set

of tests has been generaIIy recognized as acceptable to replace the IV-22 and PB-5 O commercial

recordings which are more than 20 years old.

Rerecording and adaptation, incIuding shorten1
ing of these tests, would also have been necessary for use in the national survey.

Dr. Hallowell Davis, of the Central Institute

for the Deaf, made the lists of RCID Sentences

and developmental materials from CHABA available to the Division of Health Examination Statistics, to have adapted for their use.

Under contract with the Division of Health

Examination Statistics, Dr. G. Donald Causey

and Dr. Earleen Elkins, University of Maryland,

recorded the RCID Sentences and developed the

speech discrimination test used in the Health

and Nutrition Examination Survey during

1974-75. Their methods, findings, and the restitant test based on the RCID Sentences, are

described in this report.

DEVELOPMENT OF

TEST MATERIALS

Description of Stimuli

The RCID Sentences supplied by Davis consisted of 10 lists of 10 sentences each. The following criteria were employed by the working

group of CHABA in the development of these

lists:

Vocabulary appropriate to adults.

Words that appear with high frequency in one or

more of the well-known word counts of the English

lsnguage.

Exclusion of proper names and proper nouns.

Free use of common nonslang idioms and constructions.

Avoidance of phonetic loading and tongue twisting.

High redundancy.

Low level of abstraction.

Grammatical stiucture that varies freely.5

Each list of 10 sentences contains 50 key

words so that a discrimination score based on 2

percentage points per key word may be obtained. These sentence lists were an attempt to

provide speech discrimination stimuli within a

construct more closely associated with everyday

speech.

Talker

A 24-year-old male, determined by a panel

of hearing and speech scientists to have normal

speech in relation to fundamental frequency,

articulation, general American dialect, rate, and

prosodic features, was selected as the talker. He

was unsophisticated with regard to monitored

live-voice technique for audiometric testing, but

was extensively trained in the technique prior to

the final recording session. This procedure involved the monitoring of his vocal output on the

carrier phrase of the item and allowing the stimuli to occur naturally within the sentence, ire.,

the level within each sentence varied as the

speech power of its component sounds varied.

The carrier phrase provided a reference level

around which the elements of the stimulus (occurred in their natural speech power relationships. The carrier phrase also served to prepare

the listener for the cmcoming test item during

actual test presentation.

The voice monitoring was accomplished with

the phrase “Number__.” The talker maintained

optimal needle deflection on the first syllable of

“number” and on the first or only syllable of

the digits 1 through 10.

All RCID Sentence stimuli were recorded

during one session in an effort to minimize daytoday vocal variability of the talker. When a

stimulus sentence was judged unacceptable, it

was repeated immediately or at the end of a list

and subsequently spliced into correct order.

The timing of each item was regulated by an

automatic device which triggered a light every

6.5 seconds to alert the talker. This permitted ~an

average response time of 5 seconds which had

been found adequate in a preliminary study of

men from ages 38 to 78 years.

Remrding Equipment

The RCID Sentence recordings were made in

an anechoic chamber (Industrial Acoustics Co’mpany, Inc.–IAC) with inside dimensions of 7

feet by 7 feet by 7 feet. Four microphones

(Bruel & Kjaer, Type 413 1) and cathode fol10 wers (Bruel & K.jaer, Type 2619) were

mounted in free air within the chamber. Microphone No. 1 was 24 inches from the talker’s lips

at a 30° angle to the ri~ghtof center; microphone
Microphones and 1 Microphone Tape

Cathode Followers

I

Powr Supplies Recorders

9

9

000 Q(2 @Q–i @

-m

000 Oomaoo

1

Monitor I

RMS Aud10

voltmeter i

Monitor

i

Speaker

*H Amplifier

I

Speaker

Microphone

1

9

AN ECHOIC CHAM9ER CONTROL ROOM

Figure 1-1. Schematic diagram of recording equipment and its placement.

No. 3 was 1 meter from the talker’s lips at a 20°

angle also on the right side; microp~one No. 4

was placed as No. 1 but on the left side; and

microphone lNo. 2 was placed as No. 3 but

on the left. All microphones were at a 90° angle

of incidence with respect to the talker’s lips (figs-u-es1-1 and 1-2).

Outside of the chamber, each microphone

complement was electrically coupled to its respective power supply (Bruel & Kjaer, Type

2801 ) and fed to a sepuate ampIifier and singlechannel of two magnetic ‘A-inch tape recorders

(Scully, Type 280). The outside channels of a

triple-head tape assembly were employed to

minimize the possibility of cross-talk (see figure

l-l).

The talker visually monitored his 170cal output on arms (root-mean-square) audio-voltmeter

(Bruel & Kjaer, Type 2410). A ta.lkback system

permitted communication between the chamber

-::’;’”,

l.y’Y:p-

/’” /

0’ /

/’, /

/ /

J) Microphone 1

Examiner / ‘,’

/

//

/, “

o

Talker

Figure 1-2. Diagram of talker, examiner, and microphones in

racording chamlmr.

3
and recording technicians. An investigator was

present in the chamber with the talker to aid in

monitoring and in timing.

The record gain of each channel was adjusted to a -7 dB (decibel) re zero W (volume

units) level to avoid saturation during peak vocal

output. All recording was done on low-noise tape

(Scotch Brand, Type 208) at 7?4 inches per second (ips). The signal-to-noise ratio exceeded 50

dB .

Tape Assembly Procedures

A group of hearing and speech scientists

judged the recording on channel 3 as “sounding

the most natural.” AU further procedures were

accomplished with this recording. Half-inch tape

copies were made of the master recording. T&

fist generation tape was then spliced for the

appropriate stimuli, and leader tape was inserted

between items to ensure equal intends of response time.

Tracings of the stimuli of each list were

made on a graphic level recorder (General Radio,

Type 1521-B) at 20 ips writing speed in order

that the average level of the peaks could be calculated. A 1000-Hertz (Hz) tone generated by

an oscillator (Hewlett-Packard, Model 200 AB)

was placed at the beginning of each list at the

average peak level to be used as a calibration

tone in administration of tbe test lists. A second

generation %nch tape (Scotch Brand, Type

208) was then made for experimental purposes.

Verification of Stimuli

To determine that each stimulus was the intended one, the 10 Iists were presented sound

field to 16 normal hearing college students in a

semi-sound-treated classroom. The ambient

noise level was 60 dB Sound Pressure Level

(SPL) as measured on the C-scale of a sormdlevel meter (Bruel & Kjaer, Type 2205)- 15 feet

in front of the speaker. The level of the 1000 Hz

calibration tone at the begirming of each list was

adjusted to obtain a 65 dB SPL reading on the

same meter. All lists were presented at this level

for the initial session.

Listeners were seated in front of tbe speaker

at a distance of 5 to 25 feet. They were instructed to write the entire sentence on prepared

answer sheets. Ample time was provided after

each sentence for the write-dowm task. Two days

later, the same 16 listeners performed the same

task again, sitting in tke same position relative to

the speaker as they had for the initial session.

Two changes in procedure were made. First, the

level of the 1000 Hz calibration tone was adjusted to 60 dB SPL on the sound-level meter,

and second, the ordler of list presentation was

changed. Each session took 1 hour and 10 minutes. Following the second session, the listeners

were asked to write their reactions to both the

task and stimulus material.

The results from both sessions were marked

for the number of correct key word responses.

None of the listeners had more than one error

per list, nor were any of the errors consistent

among listeners. It was concluded that the lists

all contained the correct stimuli and were not

dtiferent from each other when perceived by

normal-hearing listeners at a comfortable listening level.

The reactions of the listeners were directed

toward the repetitive and boring nature of the

task and fatigue fro m writing responses. Comments about the stimulus material were few, and

those listeners reported that the content did not

affect them one way (oranother.

Quality of Recording

The quality of a taped copy of this master

recording of the RCID Sentences was analyzed

by Mr. Edward D. Burnett, Physicist, Sound $ection, National Bureau of Standards.

His report shows the broad-band noise to be

47 dB below the reference tone (which is -9 dB

re O VU) when the tapes are played with a full

track head. This is 4 dll better than predicted

for a fourth generation tape. The type 208 tape

is well suited for this application. The reference

tone indicates the peak levels as measured at the

20 inches/second w-ding speed of a graphic level

recorder. The instantaneous peaks, as observed

on an oscilloscope, am at least 15 dB higher. The

speech waveform is highly asymmetrical as is

common for male speech. The level of the signal

on the tape is well chosen.

The reference tone does not show any appreciable second-order (distortion which indicates

that the bias wavefonm was symmetrical and no

4
heads were magnetized. No indications of overload distortion were found. The lower frequency

limit is 100 Hz which is a characteristic of the

speaker’s voice. Components up to 14,000 Hz

were detected, which indicates that heads were

in good alignment.

PI LOT STUDY

Prior to the experimental study, 10 normalhearing subjects with normal orological histories

were utilized to determine the method and sensation levels necessa~ to obtain performance-intensity functions for the RCID Sentences. The

criterion for normal hearing was a pure-tone

threshold of 10 dB or less (ANSI, 1969) at

250, 500, 750, 1000, 1300, 2000, 3000, 4000,

md 6000 Hz.

The experimental task was performed with

the subject seated in the anechoic chamber described earlier. The test materkd, reproduced by

a tape recorder (ScUUy, Type 280), was channeled through a speech audiometer (GrasonStadler, Model 162) to one earphone of a set

(Telephonic, TDH-39 in JIX--ll/AR cushions).

The same earphone ~~zis used throughout the

tests. The 1000 Hz calihr~tion tones on the RCID

tape were used to establish O dB sound pressure

level (SPL) on the speech audiometer. Periodic

calibration checks were made of the equipment

throughout the period of data collection.

Prior to the test session, subjects were told

by the examiner that they would hear Iistsaof

sentences at different signal levels and were to

repeat all or any of the ~entence. The give-back

method of response ww chosen as a result of the

stimuli verification study and the time factor.

Subjects dso received ~he instructions, prr-rccorded on t~pe, ~vhich c(lnsisted of:

You will hew ten sentmces, each preceded by a

number. Please listen carefully and repeat only the

sentence.

A systematized randomization of the lists

was employed so that c~ich list was presented an

equal number of times at the same SPL across

subjects. The first five subjects in the pilot study

received two sentences at each level beginning at

34 dB SPL and decreasing in 2 dB steps. All

subjects repeated the first two sentences correctIy. The descending method of presentation

proceeded in 2 dB steps to 16 dB SPL. At this

level all subjects were unable to respond to any

portion of the sentences. The remaining eight

lists were then presented at sound pressure Ievels

of 18, 20, 22, 24, 26, 28, 30, and 32 dB in an

ascending fashion. The examiner recorded all responses, including substitutions, on an answer

sheet containing the appropriate list stimuli. All

five subjects obtained O percent correct at 18 dB

SPL and 100 percent correct at 32 dB SPL.

The next five subjects were trained by the

same descending method with two lists, but received the following eight Iists in a descending

mode starting at 32 dB SPL and ending at 18 dB

SPL. The percentages of correct responses were

similar to those obtained with the ascending

method; however, these subjects reported a general frustration with their inability to make correct responses as the signal was attenuated. During the performance of this task, four of the five

subjects verbally responded to each stimulus

that they could not identify completely with a

phrase similar to “1 can’t make it out. ”

Based on the results and subjective evaluations of the task, two lists were used for training

the subject and the remaining eight lists for obtaining articulation-gain functions by an ascending method.

STUDY AMONG

NORMAL-HEARING SUBJECTS

Subjects and Method

One hundred college students–7 males and

93 females between the ages of 18 and 25 years–

\vere selected for participation in this experiment. Each was questioned about his orological

histo~ and screened audiometrically as in the

pilot study. Only those u-it.h normal orological

history and audiometric test results were selected for this part of the study. All testing was

done monaurdl~”, znd an equal number of students ~vere tested in the right and in the left ear.

I’erbal instructions ~vere given to each subject as

in the pilot study, and the;” also rrcriled the recorded instnsctions (at 50 dB SPL) prior to each

5
list. A systematized presentation of the lists was

employed so that each list was presented an equal

number of times as training lists and test lists at

the same signal level across subjects. Using the

equipment described earlier, each subject received the stimuli of the first two lists to accustom them to the task. Four sentences were

presented at 34 dB SPL and two sentences each

at 32, 30, 28, 26, 24, 22, 20, and 18 dB SPL.

Each of the remaining eight lists were presented

in full at each presentation level, beginning with

18 dB SPL and increasing in 2 dB increments to

32 dB SPL. All responses were made verbally

and recorded by the examiner in the manner

described earlier. The percentage of correct key

words was calculated for each list. The test session took 35 minutes.

Findings

Table 1 summarizes the data obtained with

100 normal-hearing subjects combined across

lists. Each list was heard by 10 subjects at each

presentation level, The performance-intensity

function derived from these data is shown in

figure 2. This curve has the characteristic configurate on of traditional performance-intensity

functions derived from monosyllabic stimuli in

that it exhibits a linear function which reaches a

plateau at higher sensation levels. The lower segment of the cmwe is linear and has a slope of

10-percent increase in correct responses per decibel increase in presentation leveI. This linear segment terminates at about 24 dB SPL, where discrimination scores are about 76 percent. The

Table 1. Mean, standard deviation, and standard error of tha

mean obtained with 10 lists of RCID Sentences from 100

norrml-hearing subjects at 8 presentation levels

Presentation

level

(dB SPL)

18da b..............................

20dB ..... ...... ................... .

22 dB ..... ..........................

24 da b.......................... ....

26 da b...,...,,., ............... ....

28 dB ............ .. .................

30 dB .................... .......... .

32 dB ...............................

Mean

16.66

36.7B

58.12

75.94

87.24

94.62

97.90

98.BO

Standard

deviation

17.46

24.68

23.27

20.24

14,85

7.36

3.90

2.07

Standard

error of

meen

1.74

2.47

2.33

2.02

1.49

0.74

0.39

0.21

da SOLIND PRESSURE LEVEL (FDR NORMAL. HEA181NGI

Dk~

-2 D24EE1D 12141e

dB SENSATION LEVEL (FOR lMPAIflED-HEARING)

Figure 2. Performance-intensity functions derived from mean

discrimination scores on the RCID Sentence Lists by 100

normal-hearing and 55 impaired-hearing subjects.

upper portion of the function progresses in a

curvilinear marnmr until it approaches asymptosis, and almost perfect discriminatiom~ of 99

percent is achieved at 32 dB SPL.

The measures of score variability, as indicated by the standard deviations in table 1, also

compare favorably with the literature on moncs-

‘tisyllabic discrimination. Excluding the variability

among scores at 118 dB SPL, where the range of

scores is truncated at zero, the variability was

found to be large within the linear portions of

the function. Variability decreased progressively

as the signal intensity increased to the point

where almost perfect responses were made. The

variability present at the highest presentation

level probably reflects the subjects’ random errors due to physic) logical factors or lack of attention.

As an indication of subject consistency,

Pearson correlaticm coefficients were calculated

to determine the relationship between individuals’ scores at the different levels of presentation. The coefficients shown in table 2 reveal

that scores obtained under presentation levels

adjacent to one another show higher correlations

6
Table 2. Pearson correlation coefficient from 100 normal-hearing subjects’ =or- on 10 listsof RCI D Sentencesat 8 presentation levels

I

I Presentation level (dB SPL)

Presentation level

(dB SPL)

18 dB .. ... ........................

20 da b..............................

22 dB ...............................

24 dB ...............................

26 dB ....... ......................

28 dB ...............................

30dB ...............................

20 22 24 26 28 30 32

.

1.629 1.570 1.451 1.450 1.331 .157 .181

1.613 1.611 1.451 1.387 1.202 .141

1.656 1.520 1.456 .098 1.212

1.610 1.568 1,266 .137

1.6% 1.301 .096

1.521 ~.185

.235

ls,gnifjjant difference from zero at .05 lweL

than scores obtained under levels 4 to 12 dB

apart. This trend would be expected in view of

the influence of signal intensity differences.

Each column or row follows a logical decrease in

the size of the correlation coefficient as the signal intensity difference increases. The generaI

progression of decreasing coefficients as the

presentation levels increase probably reflects the

muncatirtg effects when scores beyond 100 percent cannot be obtained. These data indicate that

subjects maintained systematic relationships

among themselves at different sound pressure

Ievek.

In an effort to evaluate interlist equivalency,

the scores of 10 subjects for each of the 10 lists

A through J at each presentation level were

drawn from the data described above. The results are shown in table 3. It is apparent from

these data that at the lower levels, particularly

those identified in the linear portion of tie

curve for 100 subjects (through 24 dB SPL), the

mean and standard deviation values are quite different. Generally, there is a range of 30 percent

from the lowest to the highest mean at these

levels. Not until the scores reach 90 percent or

better, do the mean and standard deviation

values appear similar. Tests for significant differences among means revealed that the lists were

different through 28 dB SI’L. The means of the

10 lists were not significantly different (.05 level

of confidence) at 30 and 32 dB SPL.

STUDY AMONG

SENSORINEURAL-HEARINGIMPAIRED SUBJECTS

Subjects

Fifty-five male military veterans served as

subjects for this part of the study. The age range

was 22 to 63 years with a mean age of 45 yeas.

It was the intent of this part of the study to

gather data on all patients seen at the Audiology

and Speech Pathology Section of the Veterans

Administration Hospital, Washington, D.C. who

showed any degree of sensorineural hearing impairment. Consequently, no rigid criteria for

subject selection were required. Speech reception thresholds (SRT) could be as low as 2 dB

above hearing threshold level (HTL) and puretone air conduction thresholds could be within

normal range with a drop of 25 dB HTL at only

one test frequency. The group mean SRT for the

test ears was 17 all!. Generally, the audiometric

configurations of the test ears were characterized by normal hearing in the lower frequencies

with precipitous losses at various octaves above

1000 Hz. Thirty-one percent of the test population had a flat or gradually sloping configuration. The remaining subjects showed a drop of at

least 25 dB starting at the following frequencies:

16 percent at 1500 Hz, 13 percent at 2000 Hz,

35 percent at 3000 Hz, and 5 percent at 4000

Hz.

7
Table 3. Mean, standard deviation, and standard error Of the mean Obtained On each Of 10 lists Of RCI D Sentences from 101 normalhearing subjects at 8 presentation levels

Prs5entation level

(dB Sp L)

18dB

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

Standard deviation ......

Standard error ........ .....

20 dB

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

Standard deviation .. ....

Standard error ... ....... ..

22 dB

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

Standard deviation .. ....

Standard error .............

24dB

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

Standard deviation ......

Standard error .............

26dB

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

Standard deviation .. ....

Standard error ... ..........

28 d8

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

Standard deviation ..... .

Standard error ...... .......

30dB

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

Standard deviation ......

Standard error ........ .....

32 dB

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

Standard deviation ..... .

Standard error ......... ....

A

5.20

6.55

2.07

39.40

27,57

8.73

64.80

22.37

7.08

75.60

13.98

4.42

93.40

6.26

1.98

95.40

5.50

1.74

95.40

9.05

2.86

99.60

0.84

0.27

B

17.80

18.17

5.75

44.60

27.7B

8.79

72.60

23.04

7.29

90.20

10.81

3.42

93.00

8.18

2.59

99.00

2.16

0.68

99.80’

0.63

0.20

99,00

2.16

0.68

c

26.00

21.46

6.79

37.20

31.00

9.81

67.80

22.91

7.25

89.80

8.87

2.81

96.00

4.52

1.43

98.80

1.69

0.54

98.40

2.70

0.85

99.40

0.97

0.31

D

27.80

21.18

6.70

48.40

23.64

7.48

55.00

25.94

8.21

76.40

18.52

5.86

94.20

3.05

0.97

97.20

3.55

1.12

98,20

1.75

0.55

9B.80

2.15

0.68

List of RCI D Sentences

E

8.00

8.59

2.72

37.20

22.37

7.08

41.60

20.08

6.35

62.60

24.33

7.70

71.60

15.85

5.02

84.00

6.93

2.19

88.40

2.46

0.7B

97.40

3.78

1.20

F

12.00

15.06

4.77

18.00

12.58

3 .9B

55.20

24.93

7.89

59.40

24.73

7.83

77.20

24.66

7.80

90.00

9.61

3.04

98.00

2.9B

0.94

98s30

2.67

0.84

G

——

27.60

20.39

6.45

44.20

30.13

9.54

64.40

16.97

5.37

88.00

9.57

3.03

88.60

8.17

2.59

93.20

B.34

2.64

97,20

2.86

0.91

‘99.40

0.97

0.31

H

5.20

7.61

2,41

25,60

19.97

6.32

43.00

21.61

6.84

60.00

23.87

7.55

85.80

21.15

6.69

90.80

6.27

1.9B

97.20

3.68

1.17

98.60

1.65

0.52

I

19.20

16.23

5.14

22.BO

15,67

4.96

67.00

23.84

7.59

77.60

17.33

5.48

87.80

11,72

3.71

86.20

9.26

2.93

97.80

3.71

1.17

98.60

0.84

0.27

J

.—

17.80

16.04

5.08

46.60

20.16

6.38

49.80

14,37

4.55

79.00

13.57

4.29

84.80

12.63

4.05

92.20

10.52

3.33

98.60

3.7B

1.20

98.20

2.20

0.70

Following an orological examination, bilater- the 55 male veterans selected as subjects for

al pure-tone thresholds by air and bone conduc- this part of the study on air and bone conduction were obtained for each subject. Only those tion hearing’ tests and on the W-22 Iists are sumwho had an air-bone gap of 10 dB or less were marized by age in the appendix. Among this study

retained for further testing. This consisted of a group, the degree of negative association bedetermination of their SRT’S and discrimination tween their scores on the W-22 word lists and

scores on recorded W-22 lists.4 Performance of their air-conduction hearing level at 10010 Hz
(-0.59) is similar to that with their speech reception threshoId (-0.61), i.e., those with lower or

better hearing levels attain higher W-22 scores or

hear more words correctly.

Method

The em with the better SRT was then

chosen for the monaural RCID Sentence testing.

If the SRT’S for both ears were the same, the ear

with which the subject had obtained the highest

W-22 speech discrimination score was selected.

The task was performed with the subject

seated in one room of an IAC testing suite. The

test material, reproduced by a tape recorder

(ScuUy, Type 280), was channeled through a

speech audiometer (Grason-Stadler, Model 162)

to one earphone of a set of phones (Telephonic,

TDH 49-1OZ in hlX-41/AR cushions). The same

earphone was used throughout. The 1000 Hz

calibration tones on the RCID tape were used to

establish O VU output level on the W meter of

the speech audiometer. Periodic calibration

checks were made of the equipment during the

period of data collection.

Prior to the test session, subjects were toId

by the examiner that they would hear lists of

sentences at different signal levels and were to

repeat all or any of the sentences. Subjects also

received the prerecorded instructions on the test

tape. A systematized presentation of the lists

was employed so that each list was presented a

given number of times as training lists and test

lists at the same sensation level across subjects.

The reference level for presentation was the SRT

of the subject’s test ear. For the training portion, two sentences were presented at each of

the follo~ving sensation levels (SL’S): 16, 14,

12, 10, 8, 6, 4-, 2, 0, -2 clB. The remaining

eight lists were presented in full, begirming with

O or +2 dB SL and increasing in 2 dB increments

to 14 or 16 dB SL. After data on 20 subjects

had been obtained, some variation in the initiaI

sensation level was instigated in order to explore

the performance intensity function below O dB

SL and above 16 dB SL. AU responses were

made verbally and recorded by the examiner in

the manner described in the study among the

normal-heting group. The percentage of correct

keywords was calculated for each list. The test

session took 35 minutes.

Findings

Table 4 summarizes the data obtained from

55 subjects with sensonneural losses. The number of subjects for which the data at any sensation level were obtained is indicated in the last

column. The performance-intensi~ function

derived from these data is shown in figure 2 with

the performance-intensity function obttined

from 100 normal-hearing subjects. The curve for

sensorineural subjects exhibits the linear function ~vhich appears to terminate at about 8 dB

SL, where subjects gave 74 percent correct responses. The slope of this portion of the curve

rises at a rate of about 5 percent increase per

decibel increase in intensity. The upper portion

of the function tends toward curvilinearity and

does not approach asymptosis.

The variability of the discrimination scores

about the mean values, as shown by the standard

deviations in table 4, indicates the large amount

of heterogeneity among the impaired-hearing

subjects. It is also important to observe that this

large variability is maintained from the lower

sensation levels up to 14 dB SL. A gradual decrease in subject variability is then observed but

a pattern is not apparent. Standard errors of the

mean indicate that in other populations with

similar sensorineuraI losses, one would expect

about two-thirds of the mean discrimination

scores to be pIus or minus two key words.

Table 4. Mean, standard deviation, and standard error of the

mean obtained with 10 lists of RCID Sentences at 12 sensation levels for the 55 subjects with sensorineural hearing

impairments, and the number contributing to each mean.

Sensation

level

4 dB ............

-2 da b....... ....

O da b............

2dB .............

4dB .......... ...

6 da b............

8 dB .............

ICI da b..........

12 dB .... .......

14 da b..........

16 da b..........

18 dB ...........

Mean

14.33

10.89

30.56

35.27

49.26

56.65

73.62

77.82

85.47

86.77

93.53

95.50

Standard

deviation

24.21

10.30

28.59

28.10

28.58

32.13

24.20

23.70

15.09

20.15

8.62

4.50

Standard

Number of

error of

the mean

subjects

9.88 6

3.43 9

5.72

5,13 :;

4.83 35

5.51 34

3.98 37

4.13 33

2.76 30

3.95 26

2.09 17

1.59 8

9
INTERLIST

EQUIVALENCY STUDY

In order to control the effect of variable

levels of stimuli presentation, another study was

conducted to evaluate interlist equivalency—

assessing the same subject under different experimental conditions. There would be need in

the Health Examination Survey for sentence

lists that could be used interchangeably, since

different Iists of 10 sentences must be available for use at each successive 10 dB intensity level at which the test needed to be presented. The presentation was to be continued

until the examinee was no longer able to hear

enough of the speech test to pass.

Subjects

Subjects for this experiment were twenty male military veterans with normal or impaired hearing. Their ages ranged from 23 to 69

years, with a mean age of 45.7 years. The subjects were divided into two groups of 10

each. Group 1 had speech reception thresholds

(SRT’S) in the test ear ranging from 2 to 24 dB

with a mean of 9.4 dB. Their lower pure tone

averages (PTA’s), usually two frequencies (500

and 1000 Hz), ranged from 2 to 30 dB with a

mean of 10.2 dB. Group 2 had SRT’S from O to

34 dB and a mean of 15.2 dB. The Iower PTA

for these subjects went from O to 37 dB with a

mean of 16.4 dB.

No restrictions with respect to degree, type,

or presence of hearing impairment were placed

on subject selection. Five of the subjects could

be classified as normal, two had mixed impairments, and the remainder had sensorineural impairments. All but three of the subjects had

W-22 discrimination scores of 90 percent or better in the test ear.

Following an orological examination, bilateral pure-tone thresholds by air and bone conduction were obtained for each subject as well as

speech reception thresholds and discrimination

scores on recorded W-22 lists. The test ear was

chosen on the basis of the lower PTA of the

better ear for monaural testing with the RCID

sentence lists.

Method

The experimental task was performed w-ii.h

the subject seated in one room of an WC testing

suite. The test material, reproduced by a tape

recorder (Scully, type 280), was chamieled

through an audiometm- (Allison, Model 22) to

one earphone of a set (Telephonic, TI)H

39-1OZ in MX-41/AR cushions). The sanie earphone was used throughout the test. The 1~00

HZ calibration tones on the RCID tape were

used to establish O (cm the VU (meter of the

audiometer.

Prior to the test session, subjects were told

by the examiner that they would hear lists of

sentences at a comfortable loudness level tid

were to repeat all or any of the sentences. Subjects also received file prerecorded instructions

on the test tape. A systematized presentation of

the lists was employed so that subjects in Group

1 or 2 each heard a different order of the sentence lists. The reference, level for presen~ati@

was the lower PTA of the subjects’ better ear.

Group 1 heard all I.O lists at 10 dB -SL and

Group 2 heard all 10 lists at 20 dB SL. No training lists were administered because all stiru&

were presented at a comfortable loudness level

and any learning factor would be countedmlanced by the randomization of the lists. AU responses were made verbally and recorded by the

e-xaminer in the manner described earlierj ‘l%e

percentage of correct keywords was then czilculated for each list. The test session took about

35 minutes.

;.

Findings

Table 5 describes the performance of both

groups of subjects separately and combined on

the 10 R(XD sentence lists. The mean conect

responses for Group 1 ranged from 88.8 percent

for list E to 98.2 percent for list I. The scores of,

Group 1 were statistically evaluated by, anzikys(sof variance. Statistical significance was ‘shown

for the main effect of Iists (F=2.67; df=9:,90;

p<O.05). Subsequent comparisons by Duncm’s

Multiple Range of the mean scores for 10 lists

showed that list E was significantly (p<Qi05)

lower than all of the remaining lists w+ih the

10
exception of lists F and H. There were no significant differences among the means of the nine

lists, except for list E.

The scores of Group 2 were also evaluated

by analysis of variance and no statistical signifiable 5. Mean, standard deviation, and standard error of the

mean obtained on RCID Sentence lists by 10 subjects

at 10 dB SL and 10 subjects at 20 dB SL, and by both

groups combined.

RCID SentencLiti A

Meml ..................... ..... ..

Standerd deviation .......

Standard error ............ ..

List B

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

Stantird deviation .......

Standrsrd error ..... .........

List c

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

Standati daviaton ........

Stendard error ..............

List D

Maan ..................... ..... ..

Standard dawation .. .....

Standard arbor ..............

Uat E

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

6tan&rd deviation ...... .

Strntird error ..... .........

List F

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

Standard deviation .......

Standard error ........ ..... .

tist G

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

Standerd deviation .......

Standard error ..............

List H

Maan ............................

Standard deviation .......

Standard arbor.., ...........

List I

Maan ............... .............

Standard daviation . ......

Standard error, .............

List J

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

Stsmdmd daviation .......

Standard error ...... ...... ..

;roup 1

atl O

dB SL

97.6

1.744

0.552

97.2

2.857

0.9M

96.2 ~

3.842

1.216

96.0

2.683

0.849

88.8

9.474

2.998

93.0

6.768

2.142

96.2

5.016

1.5s7

93.6

7.526

2.382

9B.2

2.088

0.661

97.2

4.490

1.421

Sroup 2

at 20

dB SL

98.6

2.375

0.752

98.8

2.040

0.645

98.2

2.272

0.719

97.6

3.555

1.125

98.4.

1.281

0.405

96.4

5.489

1.740

97.8.

2.6s30

0.823

96.6

5.142

1.627

97.6

2.154

0.682

95.8

5.173

1.637

Groups 1

and 2

98.1

2.198

0.492

98.0

2.675

0.588

97.2

3.397

0.760

96.8

3.334

0.746

94.1

8.813

1.972

84,7

6.562

1.468

97.0

4.180

0.936

95.1

6.789

1.519

97.9

2.142

0.479

96.5

5.021

1.123

cance was shown (F=O.94; df=9,90; p>O.05).

The scores from the two groups were similar at

the 10 and 20 dB SL’S, and the F-test for homogeneity of variance (HartIey’s) was performed on

the data to determine the feasibility of combining the data into one group with an N of 20. The

results of the F-test indicated that the variance

due to experimental error within each of the

treatment populations was homogeneous

(F=2,22; df=2,9; p>O.05).

Finally, an analysis of variance performed on

Groups 1 and 2 combined indicated no significant differences among the scores on the 10 sentence lists (F=l.66; df=9,190; p>O.05). The

largest mean difference for Groups 1 and 2 combined is between Lists A and E and constitutes

only 4 percent or avo keywords.

DISCUSSION

Normal Hearing

Several factors probably contribute to the

Iarge differences among means and the wide variability among scores at levels from 18 dB to 28

dB SPL. One consideration would be the Iack of

homogeneity among sentence items due to the

linguistic constraints imposed by possible word

sequences. c Quantification of sentence stimuli

for the measurement of discrimination ability

has not received much investigation, and some

of those who have worked in this area feel that

sentence stimuli are “very complicated” and require further study.]

Another factor which undoubtedly contributed to the observed differences among lists is

related to the experimental method. It has been

noted that all subjects heard the lists at speeified

levels re 0.0002 microbar, and though they had

been screened for normal-hearing, it is generally

agreed among audiologists that there is marked

variability in sensitivity among persons meeting

the normal-hearing criteria. The level which may

have been the threshoId of detectabdity or intelligibility for one subject could easily have

been displaced plus or minus several decibels for

another subject. This consideration is simply

another way of viewing the marked variability

among subjects. However, as the data across alI

11
10 lists for the entire group of 100 subjects indicates, measures of a group of tests are more

stable than measures for a single test.

The p e rf ormance-intensity function for

normal-hearing subjects is characteristic of functions obtained with monosyllabic stimuli in

~ that it contains a linear portion which reaches a

plateau at higher signal intensities. The linear

portion has a slope of 10 percent increase in

score per decibel increase in presentation level.

This linear segment terminates at a level of

about 24 dB SPL, where discrimination scores

approximate 76 percent. Asymptosis occurs at a

level of 30 dB SPL.

For normal hearing subjects, these findings

would indicate that all 10 lists of the RCID Sentences may be used interchangeably for obtaining maxi mum discrimination scores from

normal-hearing persons, provided the signal level

under earphone presentation is at Ieast 30 dB

SPL.

Hearing Impaired

Comparison of findings among the norrnalhearing and impaired-hearing populations show

marked differences. First, the slope of the linear

portion of the curve for the impaired-hearing

subjects was more gradurd-approximately 5 percent per decibel compared to 10 percent per

decibel for the normal-heting subjects. The linear portion for both groups of subjects terminated where approximately 76 percent correct responses were obtained. But this occurred at a

sensation level of 4 dB for normals and 8 dB for

the impaired listener.

The second difference between tie two

groups of subjects may be observed where the

nonlinear portion of the performance-intensity

function approached saturation. The normal

group attained this level at 32 dB SPL and the

impaired group did not achieve a plateau at the

sensation levels employed for this study.

The third difference between the normal and

impaired-hearing subjects is reflected in the subject variability within each group. As indicated

by the standard deviations, the normal-hearing

group had less variability throughout the sensation levels examined than the impaired-hearing

group. This would indicate that the impaired

group was more heterogeneous in the speech discrimination task than was the normal-hearing

group, Also, the variability within the normalheanng group decreased progressively as the signal intensity increased to the point where almost

perfect responses were made, but the same type

of pattern of intersubject variability was not

maintained by the sensorineur~ group.

Interlist Equivalency

The findings from this study indicate that

the University of Maryland recordings of the 10

RCID sentence lists could be used interchangeably for the Health and Nutrition Examination

Survey as a measure of the extent of functional

hearing impairment for normal conversational

levels of speech in the adult.population. The discrimination scores obtained from subjelcts in

Group 1 at 10 dB above the PTA of the better

ear and scores obtained from subjects in Group

2 at 20 dB above the PTA of the better ear were

statistically evaluated. As a result of score similarity between the groups of subjects and a finding of homogeneous variances, the data from

Groups 1 and 2 were combined, No significant

differences were found among any combination

of the 10 means. The standard errors of the

means indicate that with other populations, one

would expect about twe-thirds of the discrimination scores to bc within plus or minus one or

two keywords of the means obtained at 10) or 20

dB sensation levels. Ay real differences among

the lists would be apparent only if the sensation

levels of presentation were less than 10 dB and

representative of the linear portion of a subject’s

performance-intensity function for these materials. ‘,

SUMMARY

These’ developmental studies demonstrate

that the recordings of the RCID sentence lists

can readily be used as a discrimination test to

separate listeners with normal hearing from

those with senso]ineural losses. This new test,

designed for use im the Health and Nutrition Examination Survey of 1974-75, is capable of providing a rapid a.messment of hearing discrimination ability for speech sounds.

12
REFERENCES

/

lSecond Conference on Speech Discrimination, spon- rials for Speech Audiometry. ]. Speech Hear Disord.

sored by the Office of Vocational Rehabilitation. 17:321-337, 1952.

Houston, Texas, 1962. 5Davis, H., and Silverman, S. R.: Hearing and Deaf-

‘Personal communication from E. L. R. Corliss on ness, 3d ed. New York. HoIt, Rinehart and Winston, Inc.,

Some Quantitative Consequences of Hesring Loss from 1970.

the Standpoint of Communication Theory, 1975. 6Speaks, C., Jerger, J., and Jerger, S.: Performance3Egan, J. P.: Articulation Testing Methods. Laryngo - intensity ch aractenstics of Synthetic Sentences. J.

t

sco e. 58:955-91, 1948. Speech Hear Res. 9:305-12, 1966.

Hirsh, I. J., Davis, H., Silverman, S. R., Reynolds, E.

G., Eldert, E., and Benson, R.W.: Development of Mate13
APPENDIX

CONTENTS

Hearing Characteristics of the SeIISOrineuml Hearing-Impaired Subjects in the Study ..- ... . ...-.. -------------- 16

APPENDIX TABLE

L Meao, standard deviation, and standard error of the mean on air- and bone-conduction hearing tests

and W-22 word lists aud tbe correlation between akmnduction levels and W-22 sores for the 55 subjects with xnscmiuetual heruing impairments. ... .... . . . .. .. ..... .. .......... . ... . .... ..... . . . ...... .. .. ... . . . . 16
APPENDIX

HEARING CHARACTERISTICS OF THE

HEARING-IMPAIRED SUBJECTS IN

SENSORINEURAL

THE STUDY

The extent of hearing impairment for pure

tone sound in air- and bone-conduction, the sensation levels for speech reception, and the

speech discrimination level as determined with

the previously available W-22 word lists for the

55 sensorineural-hearing-impaired subjects in

this developmental study and the degree of association between the W-22 discrimination scores

and the pure tone air-conduction hearing levels

for these 55 subjects are shown in Table I. These

data are included to give a general idea of the

extent of hearing impairment for these subjects,

although as previously stated no rigid criteria for

their selection were used since all were patients in

the Audiology and Speech Section of the Veterans Administration Hc)spital in Washington, D,,C.

Table I. Mean, stendard deviation, and standard error of the mean on air- and bone-conduction hearing tests and the W-22 word lists and

the correlation between-air-conduction levels and W-22 scores for the 55 subjects with sensorilneural hearing impairments.

Air-conduction hearing levels (dB)

a

Bone-conduction hearing levels (dB) Speech test

Uumber

of

ubjects 500 1000 2000 4000 500 1000 2CIO0 4000 w-22 SL re

Hertz Hertz Hertz Hertz Hertz Hertz Hertz Hartz scores SRT

—

55 55 55 55 55 15 15 21 26 55 55

Age

Number of subjects .....

Mean values

All ages

20-64 years .......... 55 17.8 19.5 31.3 53.5 ] 29.7 I 29.7 40.9

24.4

25.0

25.0

40.2

30.6

36.7 53.3 91.8

20-29 years...,..., ..........

30-39 years .............._.

40-49 years ............. .....

50-54 years ................. .

55-64 years ................ ..

8

7

12

20

8

11.7

12.9

19.2

22.5

14.4

12.5

13.6

17.9

26.2

17.5

51.9

57.1

52.9

+63.5

65.6

42.5

57.5

45.0

+55.6

+63.8

90.5

94.6

94.8

88.0

91.8

41.2

40.9

39.5

42.3

39.5

8.13

15.0

41.7

+32.9

20.0

12.5 36.2

32.5

+42.2

28.8

3B.3

+35.0

20.0

Standard deviation

Al I ages

20-64 years .......... . . . I 14.03 I 17.29 1 21.33,1 33.921 17.60 I 20.07 16.30

I

12.41 9.09

1 1 I I 1 1 —

2&29 years ..................

30-39 years ..................

4049 years ..................

60-54 years ..................

55-64 years ..................

. . . 9.87

. . . 6.64

. . . 16.90

. . . 16.47

. . . 6.29

12.99 16.81 19.92

6.86 16.69 28.36 - 2.50

18.66- 22.63 17.42 12.35 19.35

20.49 22.95 24.35 20.43 21 .3B

8.26 11.37 20.76 4.08 12.25

12.57

II 8.87

115.53

114.19

14.36

5.60

11.65

8.35

10.52

16.31

6.32

3.88

13.18

4.04

6.24

0.95

4.55

12.23

2.18

‘1.08

Standard error of mean

All ages

2064 Veals .......... . . . 1.89 2.33 2.87 4.57 4.55 5.19

. . . 3.48 4.58 5.94 7.04 - -

. . . 2.58 2.58 6.29 10.74 1.77

. . . 4.88 5.39 6.54 5.04 7.14 11.18

. . . 3.68 4.58 5.13 5.45 7.71 8.07

. . . 2.22 2.92 4.02 7.33 2.35 7.08

3.56 2.43 1.23

—

20-29 Veals ............... ...

30-39 Veals..................

4049 years ..................

50-54 Veals ..................

6564 Veals ..................

6.28

9.44

5.18

7.10

10.18

2.80

4.39

2.78

5.26

5.76

2,39

1.12

2.95

1.42

:2.20

0.35

‘1.32

}2,74

0.77

16 *U.S. GOVERNMENT PRINTING OFFICE: 1977— 260437:26
Formerly Public Health Service Publication No. 1000 

Series 1. Programs and Collection Rocedutes.-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. 

Series 2. Data Evaluation 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. 

Series 3. Analytical 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. 

Series 4. 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. 

Series 10. Data from the 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. 

Series Il. Data from the Health Examination Survey.-Data from direct examination, testing, and measurement 

of national samples of the civilian, noninstitutionalized 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 respect to physical, physiological, and psychological characteristics; and (2) analysis of relationships among the various measurements without reference to an 

explicit finite universe of persons. 

Series 12. Data from the Institutionalized Population Surveys.-Discontinued effective 1975. Future reports from 

these surveys will be in Series 13. 

Series 13. Data on Health Resources Utilization.-Statistics on the utilization of health manpower and facilities 

providing long-term care, ambulatory care, hospital care, and family planning setices. 

Series 14. Data on Health Resources: Manpower and Facilities.-Statistics on the numbers, geographic distribution, and characteristics of health resources including physicians, dentists, nurses, other health occupations, hospitals, nursing homes, and outpatient facilities. 

Series 20. Data on Mortality.-Various statistics on mortality other than as included in regular annual or monthly 

reports. Special analyses by cause of death, age, and other demographic variables; geographic and time 

series analyses; and statistics on characteristics of deaths not available from the vital records, based on 

sample surveys of those records. 

Series 21. Data on Natality, Marriage, and Divorce.-Various statistics on natality, marriage, and divorce other 

than as included in regular annual or monthly reports. Special analyses by demographic variables; 

geographic and time series analyses; studies of fertility; and statistics on characteristics of births not 

available from the vital records, based on sample surveys of those records. 

Series 22. Data from the National Mortality and Natality Surveys.-Discontinued effective 1975. Future reports 

from these sample surveys based on vital records will be included in Series 20 and 21, respectively. 

Series 23. Data from the National Survey of Family Growth.-Statistics on fertility, family formation and dissolution, family planning, and related maternal and infant health topics derived from a biennial survey of 

a nationwide probability sample of ever-married women 1544 years of age. 

For a list of titles of reports published in these series, write to: Scientific and Technical Information Branch 

National Center for Health Statistics 

Public Health Service, HRA 

Hyattsville, Md. 20782