7//

IB 1 1-52

HANDBOOK OF

HEARING AID MEASUREMENT

1976

VETERANS ADMINISTRATION WASHINGTON, D.C. 20420
Burnett, E. D., NBS hearing aid test

procedures. Chapter III. Perforoiance

measurement data from the National

Bureau of Standards. Handbook of

Hearing and Meaurement 1976, IB 11-52,

pp, 1V299 (Veterans Administration,

Washington, DC, 1976).

200.05

KBSIR75-919. Acoustical performance of

fiscal 1976 hearing aids, 265 pages

(1976). This paper was consolidated

with another paper and published in

the Handbook of Hearing Aid Measurement

1976 and is available from OTIS as

200.05
HANDBOOK OF HEARING AID

MEASUREMENT

1976

AUDITORY RESEARCH LABORATORY

VA Hospital - 50 Irving Street, N.W.

Washington, D.C. 20422

SOUND SECTION

Institute for Basic Standards

National Bureau of Standards

Washington, D.C. 20234

BIOCOMMUNICATIONS LABORATORY

Department of Hearing and Speech Sciences

University of Maryland

College Park, Maryland 20742

Distribution: CO: (121) 100 (101B2) 2 (134A) 1 (142D1) 2

FD-SSD-NTIS FLD: HA, DO, OC - 1 ea. for public reading

facilities per VAR 552(A), 688 - 175,

PC - 25 and PDC - 5

EX: DL, LC - 1 ea. HNSO - 1 ea.
This work was supported by contracts with:

PROSTHETICS AND SENSORY AIDS

Department of Medicine and Surgery

VA Central Office - 810 Vermont Avenue, N.W,

Washington, D.C. 20420

SUPPLY SERVICE

Department of Medicine and Surgery

VA Central Office - 810 Vermont Avenue, N.W,

Washington, D.C. 20420

Editors: G. Donald Causey

Lucille B. Beck

Statistical and Computer

Science Consultant:

Earleen S. Elkins

ii
TABLE OF CONTENTS

I. INTRODUCTION

II. SUMMARY OF HEARING AID TEST PROGRAM

III. PERFORMANCE MEASUREMENT DATA FROM NATIONAL BUREAU

OF STANDARDS

IV. PERFORMANCE MEASUREMENT DATA FROM BIOCOMMUNICATIONS

LABORATORY, UNIVERSITY OF MARYLAND

V. SPECIAL TEST DATA ON HEARING AIDS SELECTED FOR

CONTRACT YEAR 1976

iii
iii
1

I. INTRODUCTION

G. Donald Causey
2

The Veterans Administration's program for measuring and evaluating

the performance characteristics of hearing aids was developed as a means of selecting a manageable group of instruments of high quality

at a reasonable cost from among the wide variety of models available

on the consumer market

.

Each year, all interested manufacturers (of record) or their agents

are sent a copy of the bid format and invited to participate in our

program. For the 1976 Contract Year, 24 manufacturers participated.

To ensure that the total number of samples would be compatible with

laboratory facilities, each manufacturer was limited to the submission of a total of seven models of his choice, selected from among

those that are currently available to the public. VA representatives

made a random selection of three sample aids of each model entered

in the program from the participating manufacturers' stock. These

aids are tested for VA by the Sound Section of the Institute of

Basic Standards at the National Bureau of Standards, and the Biocommunications Laboratory, University of Maryland, which subject the

aids to a number of specific acoustic 'and electronic measurements.

Except for those evaluated for meeting a special clinical need, aids

are placed in one or more of four power categories: mild, moderate,

strong, or extra strong. Aids with special characteristics, such

as compression, directional, and high frequency emphasis were

evaluated with others having those same characteristics. A total

of 145 models were received for this year's program. The raw test

data is turned over to VA's Auditory Research Laboratory for evaluation and conversion into a performance score or "Index of Characteristics." The Index of Characteristics is derived by applying to

the test results weighting factors which have been reviewed and

approved by a VA advisory group of consulting audiologists and

physicists. Selection of hearing aids for contract is made from

among those qualified hearing aid models which:

(a) have Index of Characteristics scores which are markedly better

than the other hearing aids in their category, or

(b) may be deemed clinically necessary to provide adequate hearing

rehabilitation for hearing- impaired veterans without reference to

their measurement results or cost per point of quality, or

(c) have the lowest cost per point of quality as obtained by dividing

the determined cost to the VA by the Index of Characteristics score,

or

(d) may be deemed necessary for research purposes.

We have indicated in Section II those hearing aids which scored in

the top 257o of their respective categories or which received a VA

contract because they possess particular characteristics needed for

special clinical problems. These aids are labeled with an asterisk.
3

This is not to say that the remaining instruments are not of value.

It simply means that they did not score as well on our tests and

that we must limit the niimber of aids on contract because of administrative problems in stocking and handling large quantities of

instruments

.

Issuance of Aids to Veterans

The selected hearing aids are purchased in quantity lots directly

from the manufacturer and stocked in the VA Supply Depot, Hines,

Illinois. The instruments are then distributed to the various VA

and contract audiology clinics in accordance with predetermined

stock level requirements.

Each hard-of-hearing veteran reporting to these clinics has an

otological examination, audiological examination, and receives a trial with 3-5 hearing aids which are known to possess characteristics which might compensate for his hearing deficiency. Once it is

determined that a particular hearing aid is most suitable for a veteran's hearing defect, he is issued that specific instrument.

When a veteran is issued a hearing aid, he is normally entitled to

be furnished hearing aid repair services and sufficient batteries to

operate the instrument. Eligible veterans are provided spare hearing

aids to utilize when their regular hearing aid is sent in for repairs so that they will not be deprived of aided hearing. Ordinarily,

the veteran who receives an initial hearing aid may return after six

months for a second instrument. The first one issued then becomes

his spare aid. Studies have shown that veterans retain their hearing

aids an average of eight years before requesting a replacement.

Veterans are furnished replacement hearing aids at such times as they are required.

The Measurement of Hearing Aid Performance

For the most part, the measurements in Section III made at the

Sound Section, National Bureau of Standards are 2cc coupler measurements, employing techniques previously described in the literature

or the standard (ANSI, 1960). With the development of the Knowles

Electronics Manikin for Acoustic Research (KEMAR) and the Zwislocki

coupler, one may measure the performance of hearing aids in ways not

previously possible. In those NBS measurements made on KEMAR, the

staff utilized the substitution method to achieve a flat input signal

throughout the frequency spectrum. These curves differ somewhat

from the curves obtained on the same instrument with KEMAR at the

Bio communications Laboratory, University of Maryland. The latter

curves represent the orthotelephonic gain of the instrument. For

this type of measurement, the gain of the instrument represents the

amplitude available at the eardrum. A full description of the

technique is included in the body of this report. In Section IV

of this Handbook appear measurements on high pass aids with open
A

earmolds, measurements on CROS aids with open molds, front to back

ratio measurements on directional hearing aids, frequency responses

of directional aids at two azimuth angles, and other measures. In

the absence of standard techniques, these methods serve to describe

in more complete fashion the manner in which hearing aids function.

In Section V of this Handbook we have provided data on the instruments

selected for contract year 1976. These data include frequency re- sponse as a function of four volume control settings (1007o, 75%, 507o,

and 25%) and frequency response as a function of tone control setting

for those aids with tone control adjustments. In addition, performance specification sheets are included for every contract aid.

Other Considerations

Individuals with hearing problems should take into account the following factors:

1. There is no "best" hearing aid for all individuals. Aids that

perform well for one person may not perform well for someone else.

Our general advice to a person with a hearing disability is to seek

professional guidance in obtaining the aid best suited to his

particular problem.

2. VA does not test all hearing aids- -only those submitted by

manufacturers who want to participate in the VA program. Of the

more than 500 hearing aid models available in the United States, VA

tests each year approximately 25%. The information contained in this

document should not be used as an absolute buying guide, and persons

not finding the aid they now wear listed among those VA buys should

not automatically conclude the device they have is inferior.

3. Information contained in this document applies for Contract Year

1976 only. New and improved hearing aids are developed each year

and as a result the information provided by VA varies from year to

year.

A. Primarily, VA provides hearing aids only to veterans whose hearing disability is the result of military service. For further

information these veterans should contact their nearest VA office

or hospital. Other veterans and all non-veterans seeking added

information are advised to consult specialists in their local communities .
SUMMARY OF HEARING AID TEST PROGRAM
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14

III. PERFOR>IANCE MEASUREMENT DATA FROM THE NATIONAL BUREAU OF STANDARDS

E.D. Burnett

M.A. Bassin

NBSIR 75-919
15

NBS HEARING AID TEST PROCEDURES

1. INTRODUCTION

This report discusses the current test procedures used by NBS to

evaluate the electroacoustic properties of hearing aids. It includes

the technical and practical reasons for performing the various tests in

the manner described and in certain cases presents ideas and preliminary

test methods for the evaluation of special-purpose* hearing aids. However, the specific details of the electronic equipment used to perform

the tests are not described.

Some of the procedures followed at NBS agree, at least in spirit,

with the procedures specified in the current national standard (1). Accordingly, the following description of the NBS hearing aid test procedures was prepared under the assumption that the reader would be familiar

with ANS S3. 3-1960 (R1971).

2. HEARING AID MOUNTING

The current national standard (1) requires that electroacoustical

measurements on hearing aids be made with the aid located in a plane

progressive sound field. The sound pressure level incident on the hearing aid microphone is determined using a separate reference microphone.

The output of the hearing aid is determined using a 2 cm^ coupler and a calibrated pressure microphone. The standard specifies two methods one

can employ for these free-field measurements: substitution and comparison. The substitution method, in which the reference microphone and the

hearing aid are interchanged, is time-consuming and therefore not used

by NBS. The comparison method, in which the reference microphone and

hearing aid are placed far enough apart so that they do not interact

*For the purposes of this report special-purpose hearing aids refer to

directional, compression, bi-cross, and open-ear mold (both near-side

fitting and cross) hearing aids. The denotation hearing aid refers to

in-the-ear, closed mold (with omnidirectional microphone), eye glass,

over-the-ear , and on-the-body hearing aids.
acoustically is almost impossible to perform accurately in a small

anechoic chamber since most loudspeakers do not have a sufficiently

symmetrical directivity pattern. Therefore, NBS employs a modification

of the comparison method wherein the reference microphone and hearing

aid microphone are placed so that both face forward towards the loudspeaker and are as close to each other as possible. The reference and

hearing aid microphone in this configuration are then most likely to be

exposed to the same acoustic pressure. A variation of this placement is

to face the hearing aid and reference microphones directly at each other,

with a spacing of no more that 2 or 3 mm. In either case, the two

microphones are exposed to the same sound pressure so that the effects

of diffraction by the coupler and any mounting hardware on the test

results are negligible. If a flat pressure response reference microphone is used, the pressure response of the aid is obtained directly

(2) . Any orientation of the aid with respect to the sound source

can be used, as long as the relative orientations of the hearing aid

and reference microphones are maintained. The requirements for a true

free field are much reduced, as long as the hearing aid microphone is

omnidirectional.

For pure-tone tests, the above procedure essentially eliminates the influence of diffraction on the test results so long as the hearing aid microphone and the reference microphone are separated by a distance which is very

small compared to the wavelength of sound at the frequency of interest.

Some of the tests at NBS use shaped random noise as a signal. In this case,

diffraction effects can modify the spectrum shape and hence the test results.

This side-by-side mounting is still used because, for this mounting, more
17

data are available on the effects of diffraction on the spectrum shape.

Hov/ever, for body aids with front-facing microphones the hearing aid is

placed on its back, and the reference microphone is hung as close as

possible to the hearing aid microphone without touching it. An example

of the frequency response curves obtained by the side-by-side measurement

and hung-microphone measurement is given in Figure 1, which was obtained

(3) for a body-type hearing aid.

The anechoic test chamber used at NBS for most of its hearing aid

testing is cubical with lateral interior (between wedge tips) dimensions

of 1.22 m. The wedges used absorb more than 99 percent of the normal

incidence sound energy at all frequencies above 175 Hz. An 8 inch loudspeaker is used to produce the sound field in which the hearing aid is

placed. The loudspeaker cabinet is placed against the back wall of the

chamber in a section in which the wedge depth has been reduced from

0.4 m to 0.3 m in order to obtain a working distance of 1 m from the

loudspeaker to the hearing aid. Such a position of the loudspeaker does

not permit the hearing aid to be placed on a net, as is often done in

small test boxes where the loudspeaker is below the test position. For

the NBS test chamber a mounting method that is as simple as the net

mounting has been developed. The reference microphone, hearing aid, and

2 cm'^ coupler are placed on a 20-cm square ledge. Tliis ledge consists

of a blanket of finely spun material about 1 cm thick. This is laid

on hardware cloth, which in turn is supported by a chemistry ring

attached to a small vertical rod. The whole assembly is essentially

acoustically transparent, although the aid and reference microphone are

placed near the front of the ledge to avoid a slight high frequency
absorption by the blanket, which can modify the spectrum shape and

thus introduce a small error in the random signal tests. This mounting

method avoids the spurious resonances sometimes produced by clamps

and introduces a minimum of extraneous diffraction of the sound.

There can be a slight problem with eyeglass aids since the positional

constraints usually require that the temple piece must cross over the

reference microphone preamplifier. When this occurs, a thin piece of

padding is placed between these two components.

3. MEASUREMENTS WITH VOLUME CONTROL AT MAXIMUM SETTING

3.1 Saturation Sound Pressure Level (SSPL) . The saturation

sound pressure level is that sound pressure level (SPL) , due to a

sound of specified spectral shape, beyond which no further increase

in acoustic output can be obtained from the hearing aid.

The SSPL is determined at NBS by using a random noise signal

having the power density spectrum shown in Figure 2. Below 200 Hz

and above 5000 Hz, the spectrum is rolled off steeply. The exact

rate of roll-off is immaterial since the roll-off is outside the

frequency limit of most hearing aids and the signal does not contribute appreciably to the overall output SPL when it is down

several dB.

The input SPL is normally set to 75 dB* and then continuously

increased until the SSPL is determined. For those hearing aids

*A11 sound pressure levels are referred to 20 pPa.
for which the sound pressure level in the coupler goes through a

maximum at a particular input SPL and then decreases, the SSPL

is easily determined. More often, the hearing aids show a clearlydefined output level which does not increase with a further increase

in the input SPL. A minority of hearing aids asjnnptotically approach

the SSPL. For these hearing aids the SSPL is defined as that output

level caused by an input SPL that, when increased 10 dB produces

an output level that increases only 0.5 dB. In no case, however,

is an input SPL greater than 90 dB used. Although it would be

quicker to use an input SPL of 90 dB for these types of hearing aids,

it is felt that it is useful to know the input SPL that produces the

SSPL.

Table 1 shows the results of this SSPL measurement on 19 hearing

aids. Related data are also included to support the various discussions that follow.

The SSPL tests provide a single number that indicates the

maximum SPL that could impinge on a user's ear. However, it

does not contain as much information as a frequency response curve

of the hearing aid at an input SPL of 90 dB, which is a common

method of estimating the saturation output level. On the other

hand the NBS determined SSPL contains as much information as the

conventional three-frequency average (4) of the output level of

the hearing aid when the input SPL is 90 dB at 500, 1000, and 2000 Hz.
20

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21

As can be seen in columns 4 and 5 of Table 1, both these methods

agree well with each other, with the NBS SSPL yielding results about

1 dB lower than the results from the three-frequency average. This

1-dB difference has been consistently measured on several hundred

hearing aids over a period of seven years. For certain hearing aids

the NBS SSPL tests indicate a much lower level than those indicated

by the three-frequency average test. (See columns 4 and 5 of Table 1

for hearing aid 2.) Even if a narrow band of noise that is centered at

the frequency corresponding to the peak output of the hearing aid is

used as the input to this hearing aid, the output level will still be

lower than that level indicated by the three-frequency average. Since

people are more often subjected to random-type sounds than pure tones,

it is felt that the NBS SSPL test is a more realistic measure of the

SSPL. In addition it gives reasonable gain figures when the volume

control setting is reduced. (See Section 4.)

The SSPL varies slightly with the rate of high frequency roll-off

of the spectrum. For example, compare column 5 of Table 1, which shows

the SSPL for the NBS spectrum which has an approximate 6 dB/oct roll-off

above 900 Hz with column 7 which shows the SSPL for a spectrum which is

similar to the NBS spectrum, but which has an approximate 12 dB/oct

roll-off above 900 Hz.

3.2 One-kHz Gain . The gain of the hearing aid is measured with

an input SPL of 60 dB. Although the Veterans Administration (VA)

discloses this data, this gain figure is not used by them in arriving

at their "index of characteristics" (3). It should be useful, however.
22

to those who fit a hearing aid.

At NBS the gain of the hearing aid is determined by two independent methods. In the first method the voltage outputs from both the

reference microphone (which is in the same sound field as is the hearing aid microphone) and the coupler microphone are recorded. These

voltages are converted to sound pressure levels using the sensitivity

of each microphone as determined using the appropriate (free-field or

pressure) procedures of American National Standard SI. 10-1966 (R1971).

The gain is determined by subtracting the reference SPL from the

coupler SPL. In the second method, use is made of an insert-voltage

technique. In effect, with the sound source off, a voltage is inserted

in series with the coupler microphone and adjusted until the microphone

output voltage is the same as when the sound source was energized.

The insert voltage is then equal to the open-circuit voltage at the

microphone when the soimd source was energized. A similar procedure is

followed for the reference microphone. The ratio of the two insert

voltages, corrected for the relative microphone sensitivities, gives

the gain of the hearing aid. By using appropriate circuitry, the gain

is actually given directly by an attenuator setting. The fact that two

methods are eiiqjloyed to determine the gain greatly minimizes the possibility of error in this measurement.

The only commonly-used alternate method for determining gain of a

hearing aid employs an input SPL of 50 dB instead of 60 dB. However,

recall the very simple, but often overlooked, relationship: Maximum

Possible Gain = SSPL - Input SPL. The lower the input SPL, the more

likely the amplifier will operate as a linear device. At a 50-dB input
23

SPL, the measured gain may be higher than can be obtained with ordinarilyencountered speech levels. This can give rise to an unnecessary "horsepower" competition in hearing aids; although the extra gain is useful

with low input levels it may be required that the volume control be set

to a low level in order to operate in the linear region for ordinary

speech levels. This may or may not be an inconvenience, depending on

the taper of the volume control.

4. MEASUREMENTS WITH VOLUME CONTROL AT REDUCED SETTING

4.1 One-kHz Gain. . The position of the hearing aid volume control

is determined by using the NBS spectriim given in Figure 2 in the following manner. The input SPL is reduced to 60 dB. The volume control is

adjusted so that the output SPL in the coupler is 12 dB below the SSPL.

If the hearing aid does not have enough gain to go 12 dB below the SSPL

with an input SPL of 60 dB, the voliime control is turned to its "fullon" position. Columns 6 and 8 of Table 1 show the reduced gains measured

with a 1-kHz tone. The corresponding columns 5 and 7 show the SSPLs that

were determined using the NBS spectrum and a spectrum with a steeper

roll-off above 900 Hz. These two different spectra result in different

settings of the volxime control. Thus the reduced gain measurement is

sensitive to the spectrum. Consequently anyone wanting to perform this

test must correct for the loudspeaker frequency response. At NBS, this

is done by using, where needed, octave and 1/3-octave filters, each of

which has an adjustable gain in its passband. For pure tones, the system

frequency response is within +2.5 dB. The deviation measured with 1/3-

octave bands of noise is within +_ 1'5 dB of the desired spectrum.
The numbers in the parentheses in Table 1 indicate the gain that

would have resulted in the desired test condition, although the hearing

aid was unable to produce this much gain. Compare columns 2 and 6 and

2 and 8 of Table 1. These required, but unattained, gains were determined by assuming that the differences between the actual input SPL that

produced an output SPL 12 dB below the SSPL and the SPL of 60 dB were

linearly proportional to the gain of the hearing aid. When the spectrum

with a 12 dB/octave roll-off was used, 8 of the 19 hearing aids had

insufficient gain for the standard test condition (12 dB below the

SSPL for a 60-dB input SPL) to be reached. When the NBS spectrum

having a 6 dB/octave roll-off was used, 5 of the 19 hearing aids had

insufficient gain. It should be noted that the reduced gains for the

spectrum with the 12 dB/octave roll-off are all higher than those

determined with the NBS spectrum having a 6 dB/octave roll-off. The

fact that 26 percent of the hearing aids tested with the NBS spectrvim

did not reach the standard test condition may indicate that the test

gains are higher than those employed by hearing aid users, who rarely

use the full volume control setting. It appears, therefore, that the

volume control setting can be reduced even more than 12 dB below the

SSPL.

The test method just described places the volume control at a

position whereby the frequency response is measured in the linear

region of the hearing aid; it also indicates a suitable gain for normal

speech levels. Implicit in this latter statement is the assumption

that the SSPL is independent of the gain setting. Some hearing aids

have a battery-saving circuit that reduces the saturation level as the
gain control is reduced. This type of hearing aid can be tested with

this technique, but may show a high distortion with an input SPL of

70 dB. (The distortion test is described below.) The compression on

some compression hearing aids minimizes the distortion by coupling the

gain to the saturation level.

4.2 Harmonic Distortion . The total harmonic distortion (THD)

measurements are made at 500, 700, and 900 Hz as stipulated in the

standard (1). In addition, the frequency at which the maximum THD

occurs is measured. Often this maximum THD occurs in the vicinity of

either 500 Hz or 1500 Hz. The maximum THD below 500 Hz is not investigated because the output SPL of most hearing aids is low in this

frequency region.

Two different input sound pressure levels are used in the

distortion measurement: 60 dB and 70 dB. The 60-dB level is repre-r

sentative of average speech levels whereas at the 70-dB level the

distortion approaches that expected near the SSPL. The volume control

of the hearing aid is set to the level determined in Section 4.1. If

a particular hearing aid has insufficient gain to reach within 12 dB

of the saturation level, using an overall input level of 60 dB for

the NBS spectrum, the input SPL is raised tmtil the hearing aid output level is 12 dB below the SSPL. This input SPL is now determined

and it replaces the previously specified 60 dB input SPL. Similarly,

the level that corresponds to the 70 dB is this new level plus 10 dB.

It should be noted that the input SPLs encountered by these hearing

aids in actual use are not any higher than the SPLs encoimtered by thos

hearing aids in which the 60 dB input SPL can be used. However,

since the purpose of the distortion test is to relate the distortion
26

at the same levels below the SSPL, it Is necessary to test these hearing aids at a higher input SPL.

The THD is determined by measuring the amplitude of those harmonics

that equal or exceed one percent of the amplitude of the test tone. However, only the THD is reported in the test results. The THD is computed

by taking the ratio of the square root of the sum of the squares of the

amplitudes of the test-tone harmonics to the amplitude of the test tone.

4.3 Signal-to-Noise Ratio . The signal-to-noise (S/N) ratio is determined at 1 kHz for an input SPL of 65 dB. The volume control setting

is that obtained in Section 4.1. The S/N ratio is determined by the difference between the hearing aid's output SPL at a 65 dB input SPL and

the hearing aid's output SPL with no acoustic input.

4.4 Battery Drain . One fresh battery is used for the three hearing

aids of each model tested, except for hearing aids that use carbon-zinc

cells. For these hearing aids a fresh carbon-zinc cell is used for each.

When the current drain is measured these batteries, which are used in all

the tests previously described, are placed in an external holder that has

leads attached to the battery terminals of the hearing aid.

The battery voltage and current drain are measured twice, first with

i no incident sound and then again with an incident sound having the NBS

spectrum and a SPL of 65 dB. The volume control setting is that obtained

in Section 4.1.

On rare occasions the lead resistance ('^^0.3 ohm) or the ammeter resistance (2-11 ohms, depending on the meter range selected) will cause

the hearing aid to "motorboat." This motorboating is eliminated by

placing a 100-300 yF capacitor across that part of the leads that are as

near as possible to the hearing aid.
27

4.5 Frequency Response . The frequency response of the hearing

aid is obtained with an input SPL of 60 dB and with the volume control

setting as determined in Section 4.1. The frequency response is

recorded on paper with a full-scale range of 40 dB. The sweep rate

is 50 sec/decade, which is adequately slow for both the compressor

to correct any fluctuations in the loudspeaker response and for the

graphic level recorder to follow its input accurately. At the same

time that this analog curve is recorded, the frequency and the sound

pressure level in the coupler are digitally recorded on magnetic tape

using 48 data points per octave. These points are equally spaced on a

logarithmic frequency scale. The digital tape is then fed to a digital

computer for analysis. The amplitude response in the 20 bands used by

the VA in their determination of the "index of effectiveness" is printed

out. In addition, a complete frequency response plot is obtained for

the purpose of cross-checking with the analog frequency response curve.

5. SPECIAL PURPOSE HEARING AIDS*

5.1 Directional Hearing Aids . In addition to obtaining the

frequency response of the hearing aid mounted and oriented with respect

to the loudspeaker as described in Section 1, the frequency response

for the directional hearing aid is also measured for sound which is

incident at 90° and perpendicular to the side of the hearing aid which

would face outwards when placed on a head. From these two frequency

responses it is possible to determine whether or not the hearing aid

*The methods described in this section are in a developmental stage and

are expected to change as these new techniques are improved.
28

microphone can be classified as either cardiod or hypercardioid. A

cardioid directivity pattern and a hypercardioid pattern are defined to

be 6 dB and 7-8 dB down, respectively, at 90°, referenced to their level

at 0°. The additional directivity of the hypercardioid is achieved at

the expense of a minor back lobe at 180° where the cardioid pattern has

a null. The directivity of the hearing aid when placed on the head will

be different from its directivity in the free field.

5 . 2 Hearing Aids for Open-Mold Fittings (High-Pass Hearing Aids) .

There are two serious problems that are encountered when the .methods

described in Sections 3 and 4 are applied to open-mold hearing aids. The

first problem is that the gain used before an unstable feedback situation

occurs (that is, when the acoustic output of the hearing aid leaks back

into the hearing aid microphone) is influenced by the geometry of the

hearing aid environment. The second problem is the strong dependence of

the pressure frequency response of the open-mold hearing aid on the configuration of the ear canal, thus barring the use of the coupler.

For these reasons the open-mold hearing aids are measured on an anthropometric manikin (6).

Mounted in the head of the manikin is a modified Zwislocki coupler (7)

,

which has a pressure microphone placed approximately where a human's eardrum is located. The coupler, in turn, is located at the end of the ear

canal which is fitted with a phantom ear mold. A tube with an internal

diameter of 2 mm connects the phantom ear mold to the hearing aid. For

the over-the-ear hearing aid the tube's length is 38.5 mm, of which 25 mm

is external to the phantom ear mold. For eyeglass hearing aids these

lengths are 55.5 mm and 42 mm, respectively.
29

The input SPL to the hearing aid is determined using the substitution

method. With the manikin removed, the pressure frequency response of the

signal-generating system is made as uniform as possible over the frequency

range of 500-5000 Hz by adjusting the gain of several 1/3-octave and

octave filters inserted between the oscillator and the amplifier driving

the loudspeaker. The manikin is then repositioned and all measurements

made on the open-mold hearing aids are obtained from the output of the

microphone in the Zwislocki coupler.

As already indicated, the maximum gain of the open-mold hearing aid

will be limited by its acoustic feedback. Therefore the SSPL gain is

found in the following manner: with the hearing aid excited by only the

ambient acoustic noise in the anechoic test chamber and the inherent

electrical noise of the hearing aid, the hearing aid's volume control is

adjusted to the maximum setting at which the output SOL, that is, the

acoustic pressure measured by the microphone in the Zwislocki coupler,

indicates no instability. The instability is indicated by a sudden increase in the output of the microphone at a specific frequency, which

varies from hearing aid to hearing aid. Using this volume control

setting, the SSPL is determined in the manner described in Section 3.1.

The frequency response of the open mold hearing aid is measured with

a 60-dB input SPL and with the volume control set such that the output

SPL of the coupler microphone is 5 dB below L^, where Lq is the output

SPL that occurs at a frequency that is substantially different from the

frequency at which the instability occurs. Prior to performing the test

to determine the gain, it is necessary to ascertain that, with the hearing aid turned off, the output SOL from the coupler microphone due to the
30

60 dB input SPL is at least 15 dB less than L . If this condition is

o not met at 1 kHz, the frequency of the input SPL is increased to 1.5-2.0

kHz v/here this 15 dB requirement is normally met. Using this reduced

volume control setting, the gain of the hearing aid is measured at 1 kHz.

The S/N ratio is determined with an input SPL of 65 dB at 2 kHz and

in the manner described in Section 4.3.

No THD measurements are made on these types of hearing aids since

most of them have a pass band that is less than one octave. High-pass

hearing aids that have a pass band greater than one octave have a very

irregular frequency response making a comparison of THD values with

other hearing aids questionable.

Battery drain for open-mold hearing aids is determined in the manner

described in Section 4.4.

6. ORTHOTELEPHONIC FREQUENCY RESPONSE

Orthotelephonic frequency response (OFR) is the difference between

the SPL that exists at an eardrum with the hearing aid in place and the

SPL that exists at the eardrum with no hearing aid, both measurements

being made with the head located in the wave produced by a constant

strength omnidirectional source (5) . This type of frequency response is

distinctly different from the previously described frequency response

measurements, where the difference between the SPL in a 2-cm^ coupler and

the SPL at the hearing aid microphone in a free field was measured.

The concept of the OFR is valid and useful for any type of hearing

aid. For hearing aids that use closed ear molds, the OFR may be approximated by adding corrections to the free-field response obtained with a

2-cm^ coupler. These corrections vary with the position of the hearing
31

aid microphone. The magnitude of the errors that result from using such

corrections is not yet known. For hearing aids that use open molds, it

does not appear that such a correction is feasible.

An approximation to the OFR is obtained by using a Zwislocki coupler

in a manikin (6), which itself is placed in an acoustic free field. Without a hearing aid in place, the coupler pressure microphone is used as

a feedback (compressor) microphone to control the signal level to the

loudspeaker as a function of frequency so that the coupler SPL remains

constant. A tape recording is made of this feedback output voltage.

When this recorded signal is used to control the signal level to the

loudspeaker, the same sound output from the loudspeaker will be produced

as if the feedback circuit was used. Using the tape recorded signal as

the input signal to the loudspeaker, a frequency response and gain of

the hearing aid are obtained when it is placed at the appropriate position

on the manikin. The output of the coupler microphone is the OFR.*

Certain precautions must be taken in using this method to determine

the OFR. First, since the loudspeaker's electromechanical properties

tend to vary with time, a new feedback signal is obtained about once a

week. Second, an error can be introduced if small changes occur in the

relative location between the loudspeaker and the manikin. This error

is caused by the change in directivity of the loudspeaker as a function

of frequency. The lack of omnidirectionality of the loudspeaker produces

another error that can greatly affect the accuracy of the OFR for body-

*This method is not valid for compression and peak-clipping type hearing

aids

.
worn hearing aids. Recall that the first step in obtaining the OFR is

to record the compressor voltage without the hearing aid. According

to the definition of OFR, an omnidirectional source is required. When

the source is not omnidirectional, the body-worn hearing aid is not

subjected to the same incident acoustic field, as the head-worn aid

would be, thereby introducing an error. This error is virtually impossible to separate from the scattering of the incident sound by the

manikin and body-worn hearing aid.

Further precautions must be taken to minimize the effect on the

free field pressure caused by the manikin's supporting structure and

by the manikin's diffraction and reradiation of the sound back towards

the loudspeaker. The former can be alleviated by wrapping fiberglass

aromd all exposed supports , whereas the latter problem can be reduced

by using a relatively small loudspeaker.

Care must also be exercised in setting the input SPL. At NBS an

additional microphone, placed between the loudspeaker and the manikin, is

used to set the output of the loudspeaker to a convenient SPL. One could

also set this level by monitoring the input voltage to the loudspeaker

for the SPL as recorded initially by the coupler's microphone in the

absence of the hearing aid.

The use of the tape-recorded signal as the input signal to the

amplifier is an advantage, since it makes the loudspeaker output

independent of the hearing aid output. This independence is especially

useful when determining the OFR of open-mold hearing aids, in which

acoustic feedback is a problem. For these open-mold hearing aids, this

method gives a realistic appraisal of their response in actual acoustic

environment.
33

Another way in which the OFR can be obtained for sovind incidence

perpendicular to the front of the manikin is to place another coupler

and microphone in the manikin's other ear. The output of this coupler's

microphone is then used as the feedback voltage to control the loudspeaker.

This procedure, however, requires the manikin, coupler, and loudspeaker

directivity to have a high degree of symmetry, otherwise errors as large

as 2.5 dB have been observed over a broad frequency range.

ACKNOWLEDGMENTS

Many of the tests described herein were developed with the advice

of a Veterans Administration committee of hearing aid consultants, which

later became the Panel on Hearing Aid Performance for the National Research

Council. The chairman of this panel was the late Raymond Carhart. Hugh

Knowles, of Knowles Electronics, and Mahlon Burkhard and co-workers at

Industrial Research Products, Inc., have worked in recent years to adapt

the orthotelephonic response concept to hearing aid measurements. Their

data, made available to NBS and as yet unpublished, have been a great help.

Some of the tests for special-purpose hearing aids have been developed in

cooperation with the Biocoramunications Laboratory of the University of

Maryland.

REFERENCES

1. Methods for Measurement of Electroacoustical Characteristics of

Hearing Aids , S3. 3-1960 (R1971), American National Standards

Institute, New York.

2. Carlson, E. V. Private communication.

3. Burnett, E. D. and Bassin, M. A., "Electroacoustical Characteristics

of Fiscal 1976 Hearing Aids," NBSIR 75-919 (National Bureau of

Standards, October, 1975).
4. Method of Expressing Hearing Aid Performance , S3. 8-1967, American

National Standards Institute, New York.

5. Inglls , A. N. , "Transmission Features of the New Telephone Systeim,"

Bell System Tech. J. 17, 358-380 (1938).

6. Burkhard, M. D. and Sachs, R. M. , "Anthropometric Manikin for Acoustic

Research," J. Acoust. Soc. Am. 58, 219-222 (1975).

7. Sacks, R. M. and Burkhard, M. D. , "Zwislockl Coupler Evaluations

with Insert Earphones," Pveport No. 2022-1, Industrial Research

Products, Inc., November 1972.
35

(ap) BSNOdsau baiivisu
T

1 1 1 1 r

(SP) 3SN0dSiu BAiivnau
ACOUSTICON' IE

model: Ai^65SSR TONEINONF RATTERY:S312 37

CODE AC-25

9

AC-2^0 AC-261

SERIAL n 3^+409 4^^191 64217

DATE JUN 2?» 1975

MEA5URE^1EMTS WITH

FULL VOL CONTROL

IKHZ GAIN DB 25.5 19.0 28.0

MPOr RANDOM NOISE

INPUT LEVELDB B3.0 80.0 77.5

OUTPUT LEVEL DB 10B.5 109.5 107.5

MEASUREtViENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB 25.5 (FULL) 19.0 28.0 (FUl

HARMONIC DIST

QINPUT LEVEL DB 65.0 75.0 65.0 75.0 61»0 71.0

500 HZ % 2 ^ 2 1 0 tJ^ 700 HZ % 1 2 3 T 3

900 HZ % a 5 6 3 6

MAX DIST % 13 2M 30 3 6

FREQ OF MAX DIS 900 1940 810 810 900 900

S/N RATIO DB

IKHZ SIGNAL 33.S ?t^.5 3M-.5

S/HUr^i PATIO DB

IKHZ SIGNAL N • M « N.M.

BATTERY DRAINr MA

NO iriPUT .5 • 6 .5

65 DL INPUT .5 .6 .5

BATTERY VOLTAGE 1.52 1.52 1.52

THE VOLUMF CONTROL WAS RFDUCED BEFORE BEGINNING THE

TEST on AC-260 RgCAUSE OF FEEDBACK.
FRFODENCY IN HPRT7

FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
ACOUSTICON HP OE

mcdel:650hp tone:none TUBING:25MM BATTERY:S13

39

CODE AC-262 AC-263 AC-264

SERIAL # 324161 5C4385 514205

DATE MAY 22. 1975

MEASUREMENTS WITH

FULL VOL CONTROL*

IKHZ GAIN DB 19.0 23.0 20 .

C

MPO, RANDOM NOISE

INPUT LEVEL. DB 83.5 82.0 84.0

OUTPUT LEVEL DB 118.0 1:24.0 118.5

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB 13.5 18.0 13.

C

S/N RATIO DB

2KHZ SIGNAL 42.0 50. 0 45.0

S/HUM RATIO DB

2KHZ SIGNAL N.M. N^. M . N.1^.

BATTERY DRAIN. MA

NO INPUT .8 .8 .8

65 DB INPUT .8 .8 .8

BATTERY VOLTAGE 1.52 1.52 1.52

^Maximum setting possible without feedback.

ACOUSTICON OE

MODEL:650R TONECNONE TUBING:22MM BATTERY:S13

41

CODE

SERIAL « DATE

MEASUREMENTS WITH

FULL VOL CONTROL

IKHZ GAIN DB

MPO* RANDOM NOISE

INPUT LEVEL, DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

©INPUT LEVEL DB

500 HZ X

700 HZ X

900 HZ X

MAX DIST X

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN. MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

AC-265

5041 1 1 AC-266

504165

FEB 4, 1975

AC-267

504209

42.5 40 .5 39.0

75.5

114.

C

75. 5

1 13.0

76.0

112.5

42.5(FULL)

60.5 70.5

3 15

2 6

1 6

3 15

500 500

42.5

N.M.

.7

.7

1 .55

40.5(FULL)

62.5 72.5

3 13

0 5

0 5

3 13

500 500

41.5

N. M.

.7

. 7

1 .55

39.C<FULL)

63.0 73.0

1 5

1 3

1 3

1 5

900 50 0

42.5

N.M.

• 6

.6

1 .55
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
ACOCJSTICON ^ MODEL:A690 ATC2 TONEIB ACOUSTIC FILTER IN TUBING:2:6MM BAT

CODE

SERIAL M

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO, RANDOM NOISE

INPUT LEVEL t DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

aiNPUT LEVEL DB

500 HZ X

700 HZ %

900 HZ %

MAX OIST %

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

AC-268 AC-269 AC-270

A24488 474462 504431

MAR 10» 1975

39.5 38,5 36.0

76.5 78.0 79.0

113.0 113.0 1 12.0 s

39.0 3 8. 5 (FULL) 36. 0< FULL

J

60.0 70.0 61.0 71.0 63.0 73.0 12 11 15. 11 11 0 4

0 2 0 2 1 6

4 42 3 22 5 95

1130 1750 1560 1710 1650 1610

40. C 39.0 40.0

N.M. N. M« N.M.

.8 -8

.8 .8 .8

1.57 1.57 1.57
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
acousticon oir eg

model:a690D tone:a acoustic filter tubing:25mm battery

CODE

SERIAL * DATE

MEASUREMENTS WITH

FULL VOL CONTROL

IKHZ GAIN 08

MPO* RANDOM NOISE

INPUT LEVEL. 08

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN D8

HARMONIC DIST

8INPUT LEVEL DB

50 0 HZ X

700 HZ %

900 HZ X

MAX DIST X

FREQ OF MAX DI

S

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

AC- 27 1 AC-272 AC- 273

434434 464387 474946

APR 30. 1975

52.5

80.5

120.0

48.5

79.0

120.0

53.5

82.5

120.

C

48.5

60.0 70.0

4 7

X 5

3 7

7 15

1550 1420

43.0

N.M.

2.1

2. 1 1.56

47.0

60.0 70.0

3 3

2 4

3 8

5 1 2

1560 1300

37.5

N.M.

2.1

2.1

1.56

48.5

60.0 70.0

4 4

1 3

3 6

6 1 1 1015 1040

43.5

N.M.

2.1

2.1

1 .56
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
acousticon

model:A7 7 0 gold

CODE

SERIAL * DATE

pwr:max(ccw) tone:ccw

OB

receiver: HP

48

batteries: 40 1(2)

AC- 274

1 13424

AC-275

19341

2

MAY 1, 1975

AC-276

474765

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN 08

MPO, RANDOM NOISE

INPUT LEVEL, OB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

ffllNPUT LEVEL

50 0 H2

700 HZ

900 HZ

MAX DIST

FREQ OF MAX OIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO

IKHZ SIGNAL

BATTERY DRAIN»

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

DB

X

X

X

X

08

MA

83.0

74.5

139.5

74.0

60.0 70.0

8 4

3 8

4 9

8 12

50 0 1080

54.0

N.M.

3.8 3.8

10.5 10.5

1.42 1.42

80.5

71.5

138.5

69.0

60.0 70.0

7 21

13

8

21

500

5

2

7

500

50. 5

N.M.

3. A 3.4

9.4 9.4

1.42 1.42

82.0

71.5

139.5

74.5

60.0

1

1

4

3

13

520

70.0

25

12

1

1

28

510

>5.0

N.M.

3.2 3.2

10.8 11,0

1.42 1.42

(
FREQUENCY IN HERTZ
audiotone

model:a20 tone:none tubing:25mm

OE

BATTERY :S76

CODE

SERIAL * DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO. RANDOM NOISE

INPUT LEVEL. DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN OB

HARMONIC OIST

cDINPUT LEVEL DB

500 HZ X

700 HZ %

900 HZ %

MAX DIST X FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 OB INPUT

BATTERY VOLTAGE

AT-274 AT-275 AT-276

4038C 40412 40419

MAR 14, 1975

47.0

77.5

121.0

47.0

77.5

120.5

47.5

77.5

120 .5

47.0 (FULL

)

62.0 72.0

5 1

4

2 6

1 4

6 2C

1470 1470

42.5

N.M.

1.8

1.8

1 .57

47.0(FULL)

60.0 70.0

4 1 2

3 6

0 3

5 15

190C 1780

41.5

N.M.

1 .8

1.8

1. 57

47.5(FULL)

60.0 70.0

6 17

3 8

1 3

7 23

1480 1460

43.0

N.M.

1.8

1.8

1 .57
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
AUO lOTONE

MODEL : A20P5

CODE

SERIAL Of DATE

tone:none tubing:25mm

AT-277

40297

HP OE

BATTERY :S76

AT-278

70322

JUNE 5, 1975

AT-279

40330

52

MEASUREMENTS WITH

FULL VCL CONTROL * IKHZ GAIN 08

MPOt RANDOM NOISE

INPUT LEVEL. DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

S/N RATIO DB

2KHZ SIGNAL

S/HUM RATIO DB

2KHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 OB INPUT

BATTERY VOLTAGE

8.0

87.0

125.0

5.0

41 .5

N.M.

2.0

2.0

1 .56

6. 0 85.0

126.0

4.0

40.0

N.M.

2. 1 2.1

1.56

8.C

85.0

L25.0

6.0

43.0

N.M.

2.0

2.0

1.56

GAIN REDUCED 5DB AT 1.5KHZ.

*Maximvnn setting possible without feedback.

AUDIOTONE OE

M0DEL;A23 T0NE:N0NE TUBING:25MM BATTERY:S76

CODE

SERIAL » DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO, RANDOM NOISE

INPUT LEVEL. OB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

aiNPUT LEVEL DB

500 HZ %

700 HZ X

900 HZ X

MAX DIST %

FREG OF MAX OIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN. MA

NO INPUT

65 OB INPUT

BATTERY VOLTAGE

AT-28G AT-aai AT-282

21964 21972 21978

MAR 17. 1975

59.5 57.5 58.0

77.0

127.0

77.0

1 28. 0

79.0

127.5

58.0

60.0 70.0

8 14

4 8

1 3

8 15

500 590

46.5

N.M.

.9

2.0

I .57

57.54FULL)

60.0 70.0

6 1 1 2 6

1 2

6 1 1 500 50d

42.0

N.M.

I .0

1.9

1 . 57

58.C(FULL)

60.0 70.0

12 21

5 9

2 3

12 21

SCO SCO

44.0

N.M.

1 . 1

1 .9

1 -57
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
audiotone

model:a24 tone:none tubing:25mm battery:S4 I OE

56

CODE

SERIAL * DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO, RANDCM NOISE

INPUT LEVEL* DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

©INPUT LEVEL DB

500 HZ X

700 HZ X

900 HZ X

MAX DIST X

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

AT-283 AT-284 AT-285

23738 23747 23782

MAR 17, 1975

45.5 45.0 44. 0

78.5

119-5

78.5

1 19.0

79.0

119.5

6 1.5 71.5

3 6

1 4

0 1 3 10

1530 1560

41.0

N. M.

1 .6

1.6

1 .57

45.0(FULL > 60.0 70.0

2 4

1 2

0 2

2 7

500 1160

40.0

N.M.

1.5

1.5

1 .57

44. O(FULL)

62.5 72.5

2 4

1 4

0 I 2 15

500 1580

40.0

N.M.

1.5

1.5

1 .57
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
AUDIOTONE OE

M0DEL:A240 TCNE:R2 TUBING:25MM BATTERY:S41

CODE

SERIAL * DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO« RANOCM NOISE

INPUT LEVEL. DB

OUTPUT LEVEL CB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC CIST

aiNPUT LEVEL OB

500 HZ %

7C0 HZ X

900 HZ X

MAX OIST %

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

AT-286 AT-287 AT-288

23671 23694 23719

MAR 18, 1975

44.5

76.

C

118.5

45. 0 77.5

I 19.0

45.0

77. 5

119.0

42.5

60.0 70.0

0 3

1 2

1 2

4 1

2

1650 1660

37.5

N.M.

1.4

1 .4

1 . 57

44. 0 60.0 70.0

0 4

1 2

0 2

4 15

1885 1880

39.5

N.M.

1.4

1.4

1 . 57

45.C(FULL)

60.0 70.0

0 5

1 3

1 2

4 18

1660 1660

40.5

N.M.

1.4

1.4

1 .57
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
AUDIOTONE

model: A25 TONEINONE TUBING: aATTERY:576

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VOL CONTROL

IKHZ GAIN DB

MPO. RANDOM NOISE

INPUT LEVEL. DB

OUTPUT LEVEL OB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

ffllNPUT LEVEL DB

500 HZ X

700 HZ X

900 HZ X

MAX DIST %

FREQ OF MAX DI S

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NC INPUT

65 DB INPUT

BATTERY VOLTAGE

AT-289 AT-290 AT-291

2648 2654 2671

MAR 18, 1975

46.0 43.0 45.0

78.5

120.0

79.0

1 }9.0

79.5

120.0

46.0<FULL) 43.0(FULL) 45.0(FULL)

62.5 72.5 60.0 70.0 63.5 73.5

2 7 3 7 3 9

1 * 13 15 1 3 2 4 1 1 2 15 3 9 3 18

500 1710 1750 1750 SCO 1634

*1«5 40.0 42.5

N.M. N.M. N.M.

1,6 1.5 1.6

1»6 1.5 1,6

1,57 1.57 1.57

AUDIOTONE DIR OE

M0DEL;A27 T0NE:N0NE TUBING:25MM aATTERY:S76

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VOL CONTROL

IKHZ GAIN DB

MPOt RANDOM NOISE

INPUT LEVEL, 06

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

©INPUT LEVEL DB

500 HZ %

700 HZ %

900 HZ %

MAX DIST %

FREQ OF MAX DIS

S/N RATIO ' DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

AT-292 AT-293 AT-294

1152 1181 1201

APR 11, 1975

49.0

86.0

127.0

48.0

84.0

126.5

47.5

84,0

126.

49.0CFULL) 46.0(FULL) 47,5(FULL)

67.0 77.0 68.0 78.0 68. C 78.0

9 15 9 9 8 1 1 3 7 2 6 3 5

1 3 1 1 2 3

9 16 9 1

2

8 12

500 556 500 630 SCO 6C5

40.0 39.0 41.0

N.M. N.M. N.M .

X .4 1 .0 1 .3

1.4 1.0 1.3

1 .57 1 .57 1 .57
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
FREQUENCY IN HERTZ
AUDIVCX EG

model:37 tone:none TUBING:35MM BATTERY:675

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN OB

MPOt RANDOM NOISE

INPUT LEVEL. DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC GIST

ffllNPUT LEVEL DB

500 HZ %

700 HZ %

900 HZ X

MAX OIST %

FREG OF MAX DIS

S/N RATIO D8

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 08 INPUT

BATTERY VOLTAGE

AU-274 AU-275 AU-276

70918 72452 72458

FEB 28. 1975

41.5 42.0 39.5

75,5 76.0 76.0

113.5 113.5 113.0

41 .5( FULL)

60.0 70.0

2 4

1 3

1 3

2 5

500 1870

41.5

N.M.

1 .2

1.2

1 .41

42.0 (FULL)

60.0 70.0

1 6

1 3

0 3

1 7

700 1510

43.0

N.M.

1.2

1.2

1.41

39-5(FULL)

62.0 72.0

1 3

0 1 1 2

2 5

1570 1660

41.5

N.M.

1 .0

1 .0

1 .41
FREQUENCY IN HERTZ
audivox hp oe

model: 101 tone:none tubingsssmm battery:s41

67

code

serial #

DATE

AU-277

72003

AU-278

72014

MAY 20. 1975

AU-279

72022

MEASUREMENTS WITH

FULL VOL CONTROL * IKHZ GAIN DB 18.0

MPO, RANDCM NOISE

INPUT LEVEL* DB 89.0

OUTPUT LEVEL DB 119.0

18.0

83.5

1 18.0

20.0

«2.5

1 18.0

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB 13.0 13.0 15.0

S/N RATIO DB

2KHZ SIGNAL 42.0 41.5 42.0

S/HUM RATIO DB

2KHZ SIGNAL N.M. N.M. N.M.

BATTERY DRAIN, MA

NO INPUT 1.2 1.2 1.2

65 DB INPUT 1.2 1.2 1.2

BATTERY VOLTAGE . 1.56 1.56 1.55

*Maxiinum setting possible without fe^lbacko
FOFOI IFNr.Y IN HERTZ
AUDIVOX

model:ii5X tone:none receiver:F2

OE

battery: S76

69

CODE Alt— 260 AU— 281 AU-282

SERIAL *

A4' £0 1 A1 U 65026

DATE FEB 2"'. 1975

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB 62.5 63.5 63.5

MPO« RANDOM NOISE

INPUT LEVEL. DB 7 A, . 0 71.5 71.5

OUTPUT LEVEL OB lo 1 • O 1 27 . 5 1 30 . 0

MEASUREMENTS WITH

RECUCEO VOLUME

CONTROL SETTING

IKHZ GAIN DB O O • O 57, 0 57.5

HARMONIC DIST

cDINPUT LEVEL OB f^O ww#w. 0 70fw.w• 0 60 . C 70 .

0

500 HZ X 2 S 5 5 3 7

700 HZ X

5 3 9

900 HZ X 3 4 4 6

MAX DIST X 10 5 6 9

FREQ OF MAX DI S Of 0 soo 1450 1380 1310 700

S/N RATIO DB

IKHZ SIGNAL f O • ^ 47 • 5 47.5

S/HUM RATIO DB

IKHZ SIGNAL KiIN .• MPI .• N • M • N.M.

BATTERY DRAIN. MA

NO INPUT • 8 1.0 .8

65 DB INPUT 4*9 5.1 4.2

BATTERY VOLTAGE 1 .56 1.55 1 .55
FREQUENCY IN HERTZ
AUOIVGX DIR EG

model: 123R0 T0NE:N TUBING:35MM battery :S76

CODE

SERIAL. * DATE

AU-283

70220

AU-284-

70602

APR 23, 1975

AU-285

70617

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB 39.0

MPO. RANDOM NOISE

INPUT LEVEL. DB 74.0

OUTPUT LEVEL DB 112,5

39.0

78.0

1 13.0

40 .0

73*0

112.5

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

ffllNPUT LEVEL DB

500 HZ X

700 HZ X

900 HZ %

MAX DIST %

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN. MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

39.0 (FULL

)

60.0 70.0

4 4

2

2

4 see43.5

N.M.

1.0

1.0

1 .57

2

0

4

500

39.0(FULL)

61.0 71.0

5 5

2

2

5

500

46. 0

N.M.

1.1

1.1

1.57

2

2

5

500

38. 0

60.0 70.0

6 6

2

2

6

50 0

43.0

N.M.

1 .0

1 .0

1 .57

3

2

6

500

THIS HEARING AID CAN BE SWITCHED TO A DIRECTIONAL

OR A NON-DIRECTIONAL PATTERN. THE BASIC DATA WERE OBTAINED

FOR THE NON-DIRECTIONAL PATTERN. REPONSE CURVES WERE

ALSO RUN AT 0 AND 90 DEGREES FOR THE DIRECTIONAL PATTERN.

FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
AUDIVOX EG

model:iii ro tone:none TUBING:35MM BATTERY:S76

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO, RANOCM NOISE

INPUT LEVEL, DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CCNTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

ffllNPUT LEVEL DB

SCO HZ %

70C HZ %

900 HZ %

MAX DIST %

FREQ OF MAX DI

S

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NC INPUT

65 DB INPUT

BATTERY VOLTAGE

AU-286 AU-287 AU-ZSa

67438 67445 69659

MAR 13, 1975

6C-0 63.0 61.5

86.0 75.0 76.0

128.0 127.0 128.0

58.5 57.0 58.0

60.0 70.0 60.0 70.0 6C.0 70.0

6 5 5 5 7 5

4 4 13 11

2 2 11 12

6 6 5 5 7 5

500 1215 500 500 SCO 5CC

43.0 45.5 43.5

N.M. N.M. N.M.

.9 .8 .9

3.0 2.0 2.2

1.57 1,57 1.57

77

DAHLBERG OE

M0DEL:HT1233 l:full comp:off TUBING:25MM BATTERY:S76

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO« RANDOM NOISE

INPUT LEVEL* DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

SINPUT LEVEL OB

500 HZ %

700 HZ X

900 HZ X

MAX DIST %

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

DA-193 DA-19^ DA-195

HT05BP HT09BP HT14BP

MAR 19. 1975

66.0

72.5

128.0

6o . C 75.0

1 28. 0

64.

C

73.0

127.

C

55.5

60.0 70.0

3 7

4 4

2 6

4 9

700 960

43.0

N.M.

3.4

4.2

I .54

56.5

60.0 70.0

4 6

5 5

2 6

5 7

700 630

41.5

N.M.

3.3

3.3

1. 54

56.5

60.0 70.

0

4 5

4 4

1 5

4 7

700 970

43.0

N.M . 3.3

3.6

1 .54

*
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
DAHLBERG EG

model:hFi250 l:full c:off TUBING:35MM BATTERY:S76

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO, RANDOM NOISE

INPUT LEVEL* DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

aiNPUT LEVEL DB

500 HZ X

700 HZ %

900 HZ X

MAX DIST X

FREQ OF MAX OIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

DA-196 OA-197 DA-198

HF15AK HF25AK HF73AK

MAR 21, 1975

67.0

74.0

129.0

66.0

75.0

129.0

71 .0

75.0

129 .0

61.0 61.0 60.5

60. C 70.0 60.0 70.0 60.0 70.0

10 15 9 20 6 12

7 9 6 11 5 8

4 7 4 9 4 5

10 15 13 30 7 13

SCO 500 1930 1690- 570 570

44.0 45.0 44.0

N.M. N.M. N.M.

3.2 3.1 3.3

4.3 4.1 4.5

1.55 1.55 1.54
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
DAHLBERG BI EG

MODEL:HG1250 BICROS LtCC* CCCCW TUBING:35MM BATTERY:S76

CODE

SERIAL M

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO. RANDOM NOISE

INPUT LEVEL. DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

5)INPUT LEVEL DB

500 HZ X

700 HZ X

900 HZ X

MAX DIST X

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

DA-199 DA-200 DA-2C1

HG82AA HG63AA HG84AA

JUN 12, 1975

70.5 71 . 5 67.5

73.0

128 .0

70.0

1 27.5

72.0

128.5

58.5

60.0

8

4

18

50 0

70.0

12

4

3

12

500

46*0

N.M.

3.4

3.8

1 .55

59. 5 57,

CO 70.0 60. 0

11 1^ 7

6 6 4

3 6 1 11 15 7

500 500 50 0

47. 0 45

N.M. N.I

3.4 3

4. 1 3

1.54 1

70. 0

9

4

4

9

5CC

2

,9

,54
FREQUENCY IN HERTZ
DAHLBERG HP OE

MQDEL:NP-2521 TONEINONE TUBIN6:25MM BATTERY:S13

CODE

SERIAL « DATE

DA-2C2

NP05BD

DA-203

NP68BC

MAY 27, 1975

DA-204

NP77BC

MEASUREMENTS WITH

FULL VCL CONTROL*

IKHZ GAIN DB

MPO, RANDOM NOISE

INPUT LEVEL, DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

S/N RATIO DB

2KHZ SIGNAL

S/HUM RATIO DB

2KHZ SIGNAL

BATTERY DRAIN, MA

NC INPUT

65 DB INPUT

BATTERY VOLTAGE

17.0

85.0

120.5

12.0

45.0

N.M.

• 6

.6

1 .56

19.0

84.0

121.0

14.0

44. 0

N.M.

• 6

.5

1.56

16.0

84.5

120.5

11.0

41.0

N.M.

• 6

.6

1 .56

*Maxiinua setting possible without feedbacko
!

i" : . ! ^

[ : ,! ii. I :

:'

——I—f—' T-j—r

T "irt "HT ^—^':i P"F^

h|:l44t : ^ „:|:_. •j;'

-ft

:Jz:f=f_t.- ^4

i 1

1 1 ! i

i

i

1

i -1 ' '/

1 ! MlJ

: 1 lb

, ;

.

M

;

1 i ! ; III !

1^14=^4

2 S »

MBAltlNS /tip MCk

,

1

: MOpEU|,.^| /nf/

00 BBRIAlitloJ j^^O

3 4 S 1 FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
DAHI.BER6 OE

M0DELIPA2526 T0NE:L TUBING:25MM BATTERY :675

CODE

SERIAL 0

DATE

MEASUREMENTS WITH

FULL VCL C0NTRC3L

IKHZ GAIN DB

MPOt RANDOM NOISE

INPUT LEVEL t DB

OUTPUT LEVEL DB

MEASUREMENTS MITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN OB

HARMONIC OIST

aiNPUT LEVEL DB

500 HZ X

700 HZ X

900 HZ %

MAX OIST X

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

DA-205 DA-2C6 DA-207

LA05AL PA63AL PA72AL

MAR 16, 1975

47,5

82.0

114.0

45.5

60.0 70.0

11 20

4 10

2 4

1 1 20

50 0 500

45.5

N. M.

• 2

. 2

1 .34

48.5

77.0

1 13.5

45.5

60.0 70.0

1 1 21

3 9

2 5

11 21

500 500

46.0

N.M.

• 2

.2

1 .37

41.5

77.

C

1 13^5

40.0

60.0 70.

0

8 7

2 3

2 3

8 8

50 0 124 0

42.

C

44.5

• 2

.2

1 .37
U Of j T n - - I f i" 111 1 : 11] iiii Mri

'

"iSsiii

!\ ii-

! til

f

^

'--""^eIiP:

1

I :[j

j j] jnejftiNip Mi) iUhe: /)^^

Ifnil 1 1 !i^#^Hf:i/fl#ia'Lf?tfl i

• 1 5 6 7 8 9 1U00

^ 1 . - i il i- - ill - !!' r ^iTji T T TT 1 II I

2 3

-liiili

^Mi:!!!!

FREQUENCY IN HERTZ

FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
DAHLBERG OE

MODEL :ri_2£27 l:cc» C:CW TUBING:25MM BATTERY:675

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO, RANDOM NOISE

INPUT LEVELi OB

OUTPUT LEVEL DS

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

aiNPUT LEVEL DB

500 HZ %

70 0 HZ X

900 HZ X

MAX DIST X

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

DA-208 DA-209 DA-21C

RL39AA RL45AA RL53AA

MAR 20i 1975

44.0

76.0

112.5

41,0

76. 0

113.0

39.5

76. 0

112.0

44.0 (FULL)

6 0.0 70.0

5 4

2 1 1 1 5 4

500 500

42.0

N.M.

1«3

1.3

1 .40

41.0(FUU_)

60 .0 70 .0

5 4

1 1

1 1 5 4

500 500

41.5

N.M.

1.3

1.3

1 .40

39.5<FULL)

60.0 70.0

5 4

0 1 1 1 5 4

50 0 5C0

39.5

N.M.

1.3

1 . 2

I .38

89

DAHLBERG OE

MaDEL:RP2528 L:FULL(CCW) P:FULL(CW) TU8ING:25MM BATTERY:675

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN 08

MPO, RANDOM NOISE

INPUT LEVEL, DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

aiNPUT LEVEL DB

500 HZ %

700 HZ %

900 HZ %

MAX DIST %

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKhZ SIGNAL

BATTERY DRAIN* MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

DA-2I1 OA-212 DA-213

RP17AA RP23AA RP28AA

MAY 15. 1975

61.0 60. 0 60.5

80.0

125 .5

81.0

1 25.0

79. 5

125.5

56.5 56,5 56.0

60.0 70.0 60.0 70.0 60.0 70. C 7 21 8 32 6 14

3 7 3 10 3 7

3 5 4 9 1 4

7 21 10 32 6 14

500 500 1310 500 500 500

48.0 45.5 45.0

N.M. N.M. N.M.

2.4 2.4 2.4

2.7 2.9 2.7

1.33 1.33 1.33

CANAVOX OB

M0DEL:727PPE T0NE:SEE below RECEIVER:4145-52 BATTERY:MN1500

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPOi RANDOM NOISE

INPUT LEVEL, DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VCLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

©INPUT LEVEL DB

500 HZ %

700 HZ %

90 0 HZ %

MAX DIST X FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

DX-127 DX-128 DX^129

24893 25993 26956

MAR 14. 1975

71 .5 72.5 73.0

77.0

134.0

73.5

1 33.5

68. 0

132.5

63.0

60.0 70.0

9 24

9 23

6 16

9 24

7C0 500

35. 0

N.M.

7.4

55.0

1 .49

61.5

60,0 70.0

9 15

9 19

8 13

9 19

700 700

39. 0

N.M.

8.4

55. 0

1 .49

6 1.5

60.C 70.0

10 21

9 18

6 14

10 21

640 50 0

41.0

N.M.

8.C

55.0

1 .49

tone:n pre-gain:max on-off:i
FREQUENCY IN HERTZ
OANAVOX OIR OE

model:735ds tcne:n TUBING:25MM BATTERY:675

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN OB

MPO« RANDCM NOISE

INPUT LEVEL» DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN OB

HARMONIC DIST

ffllNPUT LEVEL DB

500 HZ X

700 HZ X

900 HZ %

MAX DIST X

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

DX-130 OX-131 DX-ISZ

29242 39576 40557

APR 14» 1975

46.5 50.0 48. 5

83.0

120 .0

82.0

1 20.5

84.0

120.5

46.5(FULL) 50.0(FULL) 4e.5<FULL)

63.0 73.0 60 .0 70.0 62.0 72.0

0 1 1 9 14 6 10

3 5 2 5 2 5

2 3 2 3 2 3

4 12 9 14 6 11

1710 1710 500 500 500 1430

33.0 44. 5 43.0

N.M. N.M • N.M.

1.7 1 . 5 1 .5

1 .7 1 . 5 1 .5

1 .33 1 .33 1 .33
FREQUENCY IN HERTZ

OANAVOX OE

model:735S tone:n TUBING;25MM BATTERY:675

CODE

SERIAL « DATE

MEASUREMENTS WITH

FULL VOL CONTROL

IKHZ GAIN DB

MPO, RANDOM NOISE

INPUT LEVEL. DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

aiNPUT LEVEL DB

500 HZ %

700 HZ %

900 HZ %

MAX DIST %

FREQ OF MAX DI S

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

DX-133 BX-134 DX-135

42030 42061 42066

MAR 21t 1975

55.

C

77.0

120 .5

56.5

76.0

120.0

57.0

75.5

121.0

52.5

60.0 70.0

1 1 43

3 12

1 4

i 1 43

SCO 500

45.0

N.M.

1-7

1.7

1 .34

52.5

60.0 70.0

12 41

3 13

1 4

12 41

500 5C0

42.5

N.M.

1.7

1.7

1 .34

53.5

60.0 70.0

10 38

3 12

1 4

10 38

SCO 50 0 43.5

N.M.

1.7

1 .7

1 .34
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
DANAVOX

MODEL :743UN TONECa

CODE

SERIAL * DATE

MEASUREMENTS WITH

FULL VCL CONTROL * IKHZ GAIN DB

MPO, RANDOM NOISE

INPUT LEVEL, DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

S/N RATIO DB

2Kb2 SIGNAL

S/HUM RATIO DB

2KHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

TUBING:25MM

DX-136

04622

20 .0

88.0

X17.5

15.0

>38. 0 N.M.• 5 • 5 1 .42

HP OE

SATTERY:RM13 98

DX-137

04673

MAY 27, 1975

20.0

85.0 1 17.5

15.0

>39.0

N.M.

»5. 5

1,42

*Maximum setting possible without feedback.

DX-138

C5258

17.5

86.5

116.5

12.5

>36. 0

N.M.

.5. 5 1 .42
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
/ DANAVOX

M0DEL:745V T0NE:N 0UTPUT;V3 TUBING:25MM

OE

BATTERY 1675

100

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO. RANDOM NOISE

INPUT LEVEL, DB

OUTPUT LEVEL OB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC CIST

eDINPUT LEVEL DB

SCO HZ %

7C0 HZ %

900 HZ %

MAX DIST X

FREQ OF MAX DI

S

S/N RATIO DB

IK»-Z SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

DX-139 DX-140 DX-141

00705 03270 C3498

MAR 20, 1975

52.5 54. 5 53.0

74.

C

117,0

75.0

1 le.o

74.5

117.5

47.

C

60.0 70.0

4 9

3 7

1 6

10 45

1790 1830

43.0

N.M .

1.5

1.5

1 .34

51 . C 60.0 70.0

5 8

2 6

1 3

9 46

1780 1810

45. 0

N.M.

1.5

1 . 5

1 . 33

48.0

60.0 70.0

5 8

3 7

1 5

9 42

1830 183C

44.0

N.M.

1 . 5

1.5

1 .33
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
DANAVOX

M0DEL:695PPE P0WER:3 TUBING:25MM BATTERY:S76

102

CODE

SERIAL » DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN 06

MPO, RANOCM NOISE

INPUT LEVEL. DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CCNTRCL SETTING

IKHZ GAIN DB

HARMONIC CIST

©INPUT LEVEL DB

50 0 HZ %

700 HZ X 900 HZ X MAX DIST X

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 OB INPUT

BATTERY VOLTAGE

DX-142 DX-143 DX-144

86C34 86447 86494

APR 8, 1975

63.0

77. 5

127.0

64. 0

75. 0

1 26.5

61.5

74.5

126.5

55.0 55.0 56.0

60.0 70.0 60 .0 70 .0 60. 0 70. C 8 15 9 1 1 20

3 7 4 e 2 2 1 3 2 2

8 17 10 1 3 1 1 20

560 530 57C 551 500 500

45.5 46. 5 46. 5

N. M. N.M • N.M •

1 .3 1 . 2 1 . 2

2. 1 2.0 2. 1 1 .56 1 . 56 1. 56
FREQUENCY IN HERTZ
FIDELITY Q£ model:f-37 tone;n ccmp;o TueiNtGiaewM battery:675

104

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO. RANDOM NOISE

INPUT LEVEL. DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

aiNPUT LEVEL DB

500 HZ %

700 HZ %

900 HZ %

MAX DIST %

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

FI-2C8 FI-209 FI-210

743197 743281 743496

JAN 24, 1975

50.0

87,0

116.0

52.0

87.0

116.0

50.0

86.0

113.5

47.

C

60.0 70.0

5 18

3 8

2 5

5 18

500 500

41.5

N.M.

1 .9

1 .9

1 .30

47.5

60.0 70.0

3 1 1 3 6

2 3

3 1 1 700 500

41 .0

N.M.

1.8

1.8

1. 33

46.5

60.0 70.0

5 12

2 5

1 2

5 12 sro 50 0

44.0

N.M.

1.7

1.7

1 .32

FIDELITY Q M0DeL:F39 TONEIN PC:+ TUBING:25MM BATTERY:675

106

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO, RANDCM NOISE

INPUT LEVEL* DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

aiNPUT LEVEL DB

500 HZ %

700 HZ X

900 HZ %

MAX DIST %

FREQ OF MAX OIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO OB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

FI-211 ri-212 FI-213

746794 747114 747131

JAN 31, 1975

69. C 68. 0 68. 5

7 1.0

128.5

71.0

1 28. 0

71.5

128.5

60.5

60. C 70.0

20 39

6 14

3 5

20 39

50 C 500

47.5

60 . 5

60.0 70-0

18 34

6 13

3 6

1 8 34

550 550

47. 5

61.0

60.0 70.0

20 35

6 12

3 5

21 35

550 50 0 43.0

N.M. N.M. N.M.

2.5 2.5 2.5

3.2 3.3 3.3

1*33 1.33 1.32
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
FIDELITY OIR OE

mooel:f580 avc:o TUBING:25MM BATTERY:675

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPOt RANDOM NOISE

INPUT LEVEL, DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN OB

HARMONIC DIST

ffllNPUT LEVEL DB

SCO HZ %

7C0 HZ %

900 HZ %

MAX DIST %

FREQ OF MAX DI S

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN. MA

NC INPUT

65 DB INPUT

BATTERY VOLTAGE

FI-214 FI-215 FI-216

05865 05872 05892

APR 17, 1975

52.0 51.0 51.5

76.5

1 16.5

77.0

1 15.0

74,

C

116.5

46 .0

60.0 70.0

7 7

4 7

3 6

7 10

50 0 1590

41.0

N.M.

1,3

1.3

1 .37

43.0

60.0 70.0

7 5

4 4

3 4

9 6

556 1750

41 . 0

N.M.

1.3

1 .3

1.37

45.5

60.0 7C.0

7 7

5 7

3 (* 7 9

50 0 159 5

42.5

M.M.

1.3

1.3

1 .37
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ

FREQUENCY IN HERTZ

FIDELITY

MOoeL:F50 tone:none TUBING:28MM BATTERY:675

111

CODE

SERIAL ^ DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO, RANDOM NOISE

INPUT LEVEL. DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

aiNPUT LEVEL DB

SCO HZ

X

700 HZ %

'900 HZ %

MAX DIST

X

FREQ OF MAX 01 S

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

Fi-217 FI-218 FI-219

04427 04488 04524

FEB 3. 1975

57.5

72.0

121 .5

56.0

72.5

121.0

57.0

72.0

121.5

52.0 52 .0 52.5

0.0 70.0 60 .0 70.0 60.0 70. 0

17 16 15 15 18 22 2 7 2 7 1 9 0 4 0 6 0 6

17 16 15 15 18 22

SCO 500 50C SCO 50 0 50 0

51.0 51 .0 52.

C

N.M. N.

M . N.M. 1 .7 1 .7 1.7

1.7 1 .7 1^7 1 .33 1 .33 1 .33
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
FIDELITY OB

M00EL:F339 TONEIN RECEIVER:62 BATTERY: 1015

CODE

SERIAL M

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO, RANDOM NOISE

INPUT LEVEL* DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

aiNPUT LEVEL OB

500 HZ %

700 HZ %

900 HZ X

MAX DIST X FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPgT

BATTERY VOLTAGE

FI-220 FI-.221 FI-222

292548 292633 293580

FEB 4, 1975

69.0

71.5

128.5

67.5

69.0

1 28.0

67.0

72. C 128.5

57.0

60.0 70.0

6 19

9 19

2 5

12 31

670 620

50 .5

N.M.

5.0

5.0

1 .55

54.0

60.0 70.0

4 14

6 22

2 6

9 30

660 660

48.5

N.M. '

4.4

4.4

1.55

56.0

60.0 70.0

4 13

6 20

1 5

7 26

640 640

47. 5

N.M . 4,8

4.8

I .55
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
LEHR

mcdel:qptica EI-FROS

CODE

SERIAL * DATE

MEASUREMENTS WITH

FULL VCL CONTROL*

1KH2 GAIN DB

MPO. RANDOM NOISE

INPUT LEVEL. DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VCLUME

CONTROL SETTING

IKHZ GAIN DB

S/N RATIO DB

2KHZ SIGNAL

S/HUM RATIO DB

2KHZ SIGNAL

BATTERY DRAIN* MA

NO INPUT

65 OB INPUT

BATTERY VOLTAGE

tone:n tubing:4-2mm

HPS EG

BATTERY:675

LE-097

A320093

34. 5

84.0

123.0

29.5

45.5

N.M.

1 .8

1.8

1 .31

LE-098

432C0 1

1

JUN 10. 1975

33. C 84.0

1 23.5

28.0

46.5

N.M.

1.8

1.8

1.31

LE-099

4020 178

35.0

8 1.5

124.

C

30 .0

45.0

N.M .

2.0

2.C

1 .31

THESE DATA ARE FOR THE RIGHT SIDES OF A BINAURAL MODEL.

THE FOLLOWING PAGE ARE THE DATA FOR THE LEFT SIDE OF ONE

OF THE AIDS.

*Maxiinuiii setting possible without feedbacko
LEHR

OPTICA BI-FROS CONTINUATION

CODE LE-099

SERIAL # 432C102

DATE

MEASUREMENTS WITH

FULL VCL CONTROL * IKHZ GAIN DB 32.0

MPO. RANDCM NOISE

INPUT LEVEL. 08 84.0

OUTPUT LEVEL DB 121.5

MEASUREMENTS WITH

REDUCED VCLUME

CONTROL SETTING

IKHZ GAIN DB 27.0

S/N RATIO DB

2KHZ SIGNAL 46.5

S/HUM RATIO DB

2KHZ SIGNAL N.M.

BATTERY DRAIN. MA

NO INPUT 1.8

65 DB INPUT 1.8

BATTERY VOLTAGE 1.31

*Maximxiin setting possible without feedbacko

118

I

FREQUENCY IN HERTZ
LEHR

model:optica e tone:l tubing:35mm battery :675

119

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN OB

MPO, RAND CM NOISE

INPUT LEVEL. DB

OUTPUT LEVEL 08

MEASUREMENTS WITH

REDUCED VOLUME

CCNTRCL SETTING

IKHZ GAIN DB

-ARMONIC DIST

aiNPUT LEVEL DB

50 0 HZ %

700 HZ %

9C0 HZ %

MAX OIST %

FREG CF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 OB INPUT

BATTERY VOLTAGE

LE-100 LE-101 LE-1C2

4300349 4300472 4300538

MAR 4. 1975

50-0

76.0

120.

C

55.5

75.0

121.0

53.5

74.0

120.5

47.0

60.0 70.0

4 6

3 5

2 3

6 10

610 610

38.0

N. M.

1 .9

1 .9

1 .40

49.0

60.0 70.0

8 18

4 9

2 4

9 19

530 530

40.5

N.M.

1.9

1.9

1.38

50.0

60.0 70.-0

6 15

3 7

2 3

7 15

550 50 0

42.5

N.M.

1 .7

1 .7

1 .38
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
LEHR OIR OE

model:*6Avc-d avc:ccw pc:cw tubing:25mm battery:675

CODE

SERIAL * DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPOi RANDCM NOISE

INPUT LEVEL, DB

OUTPUT LEVEL OB

MEASUREMENTS WITH

REDUCED Va_UME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC CIST

aiNPUT LEVEL DB

500 HZ X

700 HZ %

9CC HZ %

MAX DIST X

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

LE-103 LE-104 LE-105

4301578 4301602 4310255

APR 18, 1975

44.5

85.0

120.0

44. 5

84.0

1 19.5

44.5

84.5

119.5

44. 5 (FULL) 44. 5 t FULL) 44. 5( FULL)

66.5 76.5 64.0 74.0 65.5 75.5

5 10 5 8 3 5 14 12 12

0 1 CI 0 0

621 510 5 13

1640 164C 500 1790 1695 1695

41.0 38.5 39.5

N.M. N.M. N.M.

1.7 1.5 1.6

1.7 1.5 1.6

1.33 1.33 1.33
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
LEHR

M0DEL:*6F PC:CW TUeiNG:25MM BATTERY:675

OE

CODE

SERI AL

DATE

LE-106

430 1399

LE-107

43071 30

FEB 24, 1975

LE-108

43072C1

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO. RANDOM NOISE

INPUT LEVEL. DB

OUTPUT LEVEL OB

65.0

70.5

127.0

60.5

71.5

1 26.5

61.5

72.5

127.5

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

t-ARMOMC CIST

SINPUT LEVEL DB

50 0 HZ X

700 HZ X

900 HZ %

MAX DIST %

FREQ OF MAX 01

S

S/N RATIO 08

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 08 INPUT

BATTERY VOLTAGE

56 .0

60.0 70.0

6 10

I0

6

50 0

46.0

N.M.

2.8

3.3

1 .33

4

0

10

500

54.0

60.0 70.0

4 7

10

4

500

43. 5

N.M.

2.8

3.5

1 .33

2

2

7

500

56. C

60 .C

5

10

5

500

7C. 0

8

2

2

8

500

43.5

N.M.

2.8

3.3

1 .33
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
LEHR HP OE

model:*6h tone h:ccw pc:cw TUBING:25MM BATTERY:675

126

CODE

SERIAL #

DATE

LE-1C9

4295C02

LE-1 10

43 12G77

JULY 2, 1975

LE-1 1

1

4313026

MEASUREMENTS WITH

FULL VCL CONTROL * IKHZ GAIN DB 7,0

MPO, RANDOM NOISE

INPUT LEVEL, DB 86,0

OUTPUT LEVEL DB 120.0

7.0

86.0

121.0

7.5

86.0

122.

C

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

S/N RATIO DB

2K»-Z SIGNAL

S/HUM RATIO DB

2KHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

4»0

37.0

N. M.

1 .9

1 .9

1 .33

3.5

39.5

N.M.

1 .9

1 .9

1 .33

4.0

40.0

N.M.

1.9

1.9

1 .33

*Maximum setting possible without feedbacko

I

LEHR OE

mgoel:s44 tone:cw TUBING:25MM BATTERY:RM13

<^ODE LE-112 LE-113 LE-114

SERIAL ft 4310249 4310271 4310289

DATE FEB 28, 1975

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN 08 56 .0 54. 0 52 . 0

MPO. RANDOM NOISE

INPUT LEVEL, OB 70.

C

71.0 73.0

OUTPUT LEVEL DB 114.5 114.0 114.0

MEASUREMENTS WITH

REDUCED VCLUME

CONTROL SETTING

IKHZ GAIN DB 49.0 47. 5 48.0

HARMONIC DIST

5)INPUT LEVEL DB 60.0 70.0 60.070.0 60 . 0 70 .

0

500 HZ % 1 1 30 10 30 1 3 40

700 HZ % 2 5 2 5 2 7

900 HZ % 1 1 1 I 0 1 MAX DIST X 1 1 30 10 30 13 40

FREQ OF MAX DIS 50 0 500 500 500 500 500

SXN RATIO DB

IKHZ SIGNAL 50.0 49.0 49.0

S/HUM RATIO DB

IKHZ SIGNAL N.M. N.M . N.M.

BATTERY DRAIN, MA

NO INPUT • 9 1 .0 .8

65 DB INPUT .9 l.G • 8

BATTERY VOLTAGE 1 .38 1 . 37 1 .35

LEHR OB

mqdel:ii5F pc:ccw rece i ver :l 120 sattery :mni50C

130

CODE

SERIAL

DATE

LEI 15A

4310 039

APR 3. 1975

LE-1 16

43 10078

MAR 6. 1975

LE-1 17

43102 10

MAR 6, 1975

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB 76.0

MPO. RANDOM NOISE

INPUT LEVEL. DB 77.0

OUTPUT LEVEL DB 135.0

78. 0 71.5

135.5

79. C 72.0

135.5

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

©INPUT LEVEL

500 HZ

700 HZ

900 HZ

MAX DIST

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO

IKHZ SIGNAL

BATTERY DRAIN,

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

DB

%

%

%

%

DB

MA

65.0

60.0 70.0

11 15

10

2

1 1 50 0

50 . 5

N.M.

3.9

10.8

1.52

10

5

15

500

63.0

6C.0 70.0

10 19

9

2

IC

500

51.0

N.M.

3.7

9.3

1-52

14

5

19

560

67.0

60.0 70.0

10 16

9

2

10

52. 5

N.M.

3.7

10 .6

1.51

8

4

16

50 0

LE-1 15, SERIAL # 420026, WAS CONSIDERED DEFECTIVE BECAUSE

FOR CERTAIN HIGH FREQUENCY INPUTS THE OUTPUT

CONSISTED OF A BROADBAND NOISE. SEE THE ATTACHED SAMPLE

SPECTRUM
FREQUENCY IN HERTZ
MAICO DIR OE

model:cq mk 100 pwr:max(ccw) tubing: 25MM BATTERY:S76

132

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN OB

MPO. RANDOM NOISE

INPUT LEVEL. DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VCLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

aiNPUT LEVEL DB

SCO HZ X

700 HZ %

900 HZ %

MAX DI ST %

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO OB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

MA-181 MA-182 MA-183

98825 98836 98898

APR 21, 1975

53.0 46. 0 47.0

77.0

113.0

83.0

1 14.0

82.0

113.0

47.0

60-0 70.0

9 8

2 3

0 2

23 67

1754 1754

46. 0

N. M.

1.2

1.2

1 .57

46 . 0

6 1 .C 71.0

8 6

2 3

1 1 14 47

1790 1790

45. 0

N . M.

1 • 1 1.1

1.57

45.0

60.0 70.0

10 5

2 2

1 1 24 68

18C0 180 0

42.0

N.M .

1.2

1.2

1 .57

THE GAIN ON MA-182 HAD TO BE REDiJCED SLIGHTLY BEFORE

BEGINNING THE TEST TO PREVENT FEEDBACK.
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
MAICO HP QE

MODELZDE LAUREL OUTPUT:CW GRN TONE SCR TUBING: 25MM BAT:S13

135

CODE

SERIAL

DATE

MA-184

17210

MA-185

17233

MAY 27, 1975

MA- 186

17252

MEASUREMENTS WITH

FULL VCL CONTROL * IKHZ GAIN DB 24.5

MPO, RANDOM NOISE

INPUT LEVEL, DB 85.5

OUTPUT LEVEL DB 117.5

22.0

84.5

117.5

24,0

85.0

1 19.5

MEASUREMENTS WITH

REDUCED VCLUME

CONTRCL SETTING

IKHZ GAIN DB

S/N RATIO DB

2KHZ SIGNAL

S/HUM RATIO DB

2KHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

19.5

30.0

.3

.3

,56

17.0

36.0

N.M.

.3

.3

I . 56

19.0

25.5

N.M .

.3

.3

1 . 56

*Maxiniuin setting possible without feedback.

/

NORELCO OE

M0DEL:HP8252 TONE INCNE TUBING:25MM BATTERY:675

137

CODE

SERIAL

DATE

NO-145

50006

NO-146 NO-147

50027 50C32

FEB 20, 1975

MEASUREMENTS WITH

FULL VOL CONTROL

IKHZ GAIN DB

MPO, RANDOM NOISE

INPUT LEVEL, DB

OUTPUT LEVEL DB

43.5

74.0

111.0

46. 0

74.0

1 12.5

47.0

73.0

112.5

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC CIST

aiNPUT LEVEL

500 HZ

700 HZ

90 0 HZ

MAX DIST

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO

IKHZ SIGNAL

BATTERY DRAIN,

NC INPUT

65 DB INPUT

BATTERY VOLTAGE

DB

%

%

X

%

DB

MA

38.0

6 0.C 7C.C

2 2

1 0

1 1 5 41

1620 1860

42.0

N.M.

• 9

.9

1 .38

41 . 0

60.0 70.0

1 1 0 1 1 5

3 40

1590 1530

43. 5

N.M.

.9

.9

1.38

40. C

6C . 0

2

1

13

70. C

2

1

1 50

1660 187 0

41.0

N.M .

.9

.9

1 .37
FREQUENCY IN HERTZ
NORELCG HP OE

MCDEL:HP8269 HFR&VTC TUBING:25MM BATTERY:675

139

CODE

SERI AL

DATE

NO- 148

04C555

NO- 149 NO- 150

40582 40829

MAY 20» 1975

MEASUREMENTS WITH

FULL VOL CONTROL * IKHZ GAIN DB 16-0

MPO. RANDOM NOISE

INPUT LEVEL. DB 84.0

OUTPUT LEVEL DB 120*5

19.5

85. 0

120.5

17.0

84.0

12C.0

MEASUREMENTS IKITH REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

S/N RATIO DB

2KHZ SIGNAL

S/HUM RATIO DB

2KHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

10.0

49.0

N.M.

2.4

2.4

1 .34

14.5

51 . 5

N.M.

2.5

2. 5

1 . 33

11.0

49.

r

N.M.

2.4

2.4

1 .33

*Maxim\im setting possible without feedback.,

ncrelco

MODEL :HP8274 C LIM TIME TC

CODE

SERIAL » DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO. RANDOM NOISE

INPUT LEVEL, DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

©INPUT LEVEL

50 0 HZ

700 HZ

9C0 HZ

MAX DIST

FREQ OF MAX OIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN. MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

DB

%

X

%

NO-15

1

25010

tone:see below

NO-152

25012

OE

TUBI NG: 25MM

141

BATTERY:675

58.0

74.0

117.5

44.0

60.0 70.

C

2 6

1 2

1 3

4 6

1590 1530

40.0

N.M.

2.3

2.3

1 .35

FEB 20* 1975

58.5

73. 0

1 17.5

45.0

60 .0 70.0

3 6

1 3

1 3

4 1

0

1830 1830

40.0

N.M.

.5

2.5

I .34

NO-153

25020

57.5

72.0

1 16.C

43.5

60.0 70.0

3 6

1 3

1 3

3 7

SCO 189 0

39.5

N.M .

2.C

2.0

1 .34

tone:n lim:5 f/s:s cf:7
FREQUENCY IN HERTZ
NORELCO OE 143

MODEL :HP8275E C$VC LIM TIME TC TONECBELOW TUBING:25MM BATTERY:675

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO, RANDOM NOISE

INPUT LEVEL, DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

ffllNPUT LEVEL DB

SCO HZ X

700 HZ %

900 HZ %

MAX DIST %

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

N0-15A NO-155 NO-156

80Q14 8C040 80C46

FEB 21, 1975

47.5 47.5 48.5

68.5 69.0 69.0

107.0 107.5. 108.0

37.0 37.0 37.0

60.0 70.0 60.0 70.0 60 .0 70. 0

19 50 16 47 22 61

7 1 1 6 1 1 7 14

9 14 8 14 1 1 22

24 50 23 66 30 61

1635 500 500 500 160 0 5G0

40 .0 38. 5 36.5

N. M. N.M' • N.M •

.6 • 6 • 6

.6 • 6 • 6

1 .35 1 . 33 1 .33
FREQUENCY IN HERTZ
NORELCO OE

MODEL :hp8276vtc&tc tone:n pc:5 vtc:ccw TUBING:25MM BAT:675 145

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO, RANDOM NOISE

INPUT LEVEL, DB

OUTPUT LEVcEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

aiNPUT LEVEL OB

500 HZ %

700 HZ %

900 HZ %

MAX QIST %

FREQ OF MAX DI

S

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

NO-157 NO-158 NO-159

50628 5C647 50655

FEB 21, 1975

64.0

70.0

127.5

63.0

69.0

1 27.5.

61.5

71.0

127.5

53.5

60.0 70.0

8 12

2 2

2 4

8 12

50 0 500

44.0

N.M.

2.5

3. 1

1 .32

53. 0 60.0 70.0

10 1 5

2 3

3 5

10 15

500 5C0

42.0

N.M.

2.8

3.2

1 .35

53.0

C.G 70. 0

9 13

2 3

3 4

9 13

5C0 50 0

4 3.C

N.M.

2.4

3.4

1 .33

NORELCO

M0DEL:HP8283

CODE

SERIAL J!f DATE

tone:n pc:5 tubing:25mm

DIR OE

BATTERY : 675

NO- 160

0463C4

NO-161

046318

APR 15. 1975

NO- 162

C46341

147

MEASUREMENTS WITH

FULL VOL CONTROL

IKHZ GAIN DB

MPO. RANDCM NOISE

INPUT LEVEL. DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VCLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

aiNPUT LEVEL

SCO HZ

700 HZ

900 HZ

MAX DIST

FREQ OF MAX DI

S

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO

IKHZ SIGNAL

BATTERY DRAIN.

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

DB

%

%

%

X

DB

MA

54.0

81.0

119 .5

45 .0

60.0 70.0

0 4

1 2

1 2

3 12

1272 1429

35.5

N.M.

2.2

2. 2

1 .33

57.0

79.5

1 20.0

45.5

60.0 70.0

2 3

0 1

1 1 2 1 4

500 1437

39. 0

N«M.

2.2

2. 2

1 .33

51.5

79.0

1 19.

C

42.5

60. 0 70.0

0 2

C 1

1 1 1 12

900 1440

33.

C

N.M.

2.2

2.2

1 .33
FREQUENCY IN HERTZ
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
NORELCO DIR GE

model: HPS 2e8AMG-TC TONe:N AM<3:MAX TUBINGi2bMM BATTERY :675

150

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPOt RANDOM NOISE

INPUT LEVEL, DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

aiNPUT LEVEL DB

50 0 HZ %

700 HZ %

900 HZ %

MAX DIST %

FREQ OF MAX Dl

S

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

N0~163 NO-16A NO-165

85008 85023 85^43

APR 21, 1975

45.5

81 .0

115.5

44.5

81.5

1 14.0

49, 5

82.

C

116.5

41.5

60. C 70.0

5 10

1 4

2 6

5 40

1730 1576

37.5

N. M.

.7

.7

1 .34

39.5

60-0 70.0

4 7

1 3

2 6

8 24

1717 1595

35.5

N.M.

.7

.7

1 .33

43.0

60. C 70.0

6 12

2 6

3 9

8 31

1755 1554

38.0

N.M .

.9

• 9

1 .33
FREQUENCY IN HERTZ
Tpiijl". - -

" - f

V

^

'

'

[' :"'';|:'

• ;

•

| . —-—— \^ ^rj^^lt

I " 3 4 5 6 7 8 9 10€0 Z 3 ., " s'' —«1- FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
OTARICN OE

MGOEL : TONETTE TONEINONE TUBING:25MM aATTERY:S13

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO, RANDOM NOISE

INPUT LEVEL, DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

SINPUT LEVEL DB

SCO HZ %

700 HZ %

900 HZ %

MAX DIST %

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

OA-259 OA-260 OA-261

42883 42901 42925

APR 9, 1975

47.5

84.0

118.5

46.5

81.5

1 17.5

47.0

32.5

119.0

47.5(FULL

)

63.0 73.0

15 50

5 13

2 6

18 57

540 526

48.5

N.M.

• 9

.9

1 .56

46.5CFULL)

63.0 73.0

9 42

3 10

1 3

31 60

5 83 568

45.5

N.M.

.9

. 9

1 .56

47, 0( FULL)

63.0 73.0

10 36

3 17

1 5

10 36

50 0 50 0

42.5

N.M.

.9

.9

1 .56

OA-261, SERIAL ^ 429C1, INITIALLY HAD A PEAK NEAR 50CHZ,

WHICH DISAPPEARED WHEN THE AID WAS RAPPED.
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
OTARION

MGDEL:LI STENETTE tone:none BATTERY;S13

IE

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO, RANDOM NOISE

INPUT LEVELf DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

•-ARMONIC CIST

SINPUT LEVEL DB

500 HZ %

700 HZ %

900 HZ %

MAX DIST %

FREQ OF MAX DI S

S/N RATIO DB

IKI-Z SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN* MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

OA-262 OA-263 OA-264

R4104 A4586 A4620

JUN 18. 1975

37.0 31.0 33.0

78.0

112.0

79.0

117.0

79.0

113.5

37. C{ FULL ) 30. 0 33.C(FULL)

60.0 70.0 60.0 70.0 60.5 70.5

4 5 0 1 0 3

1 2 12 19 3 5

1 3 7 11 5 6

4 6 18 32 5 6

500 1510 680 680 9C0 1510

41.0 29. 5 36. 5

N.M. N.M. N.M.

1 .0 1.0 1.0

.9 .9 1 .0

1 .54 1 . 54 1 .54
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
OTARICN BI EG

MOOEL:X102 BICROS TONEINONE TUBING:35MM BATTERY:S76

CQOE

SERIAL * DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO» RANDOM NOISE

INPUT LEVEL. DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC CIST

aiNPUT LEVEL DB

SCO HZ %

700 HZ %

9C0 HZ y. MAX DIST X

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

OA-265 OA-266 OA-267

213573 213788 213930

JUN 12i 1975

47.0

77.0

120 .5

45. 5

79.5

1 19.5

48. C 77.5

121.0

46«0

60.0 70.0

1 4

1 2

0 2

5 35

1770 1800

48.0

N.M.

2.4

2.4

1 .56

44.5

60.0 70.

C

2 5

2 4

3 6

7 38

1750 1780

47.5

N.M.

2.4

2.4

1.55

47.5

60. C 70.0

2 7

1 5

1 5

4 26

1720 1740

48. 0

N.M.

2.2

2.2

1 .55

CTARION CROS EG

MODEL:X101 CROS TCNE:N0NE TUBING:42^4W BATTERY:S76

159

CODE

SERIAL

DATE

OA-268

305C55

OA-269

305075

JUN 6. 1975

OA-270

305079

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN OB 33.

C

MPO, RANDOM NOISE

INPUT LEVEL* DB 84.0

OUTPUT LEVEL CB 117.0

32.0

82.5

1 17.0

20 .0

89 .0

I 1 6 . C MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

S/N RATIO DB

2KHZ SIGNAL

S/HUM RATIO DB

2KHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 OB INPUT

BATTERY VOLTAGE

26.

C

48. 5

N.M.

2.4

2. 4

1 . 55

27. 0

52.0

N.M.

2.4

2.4

1 . 55

15.

C

>38.0

N.M . 2.2

2.2

1 .55
FREQUENCY IN HERTZ
OTICON "-"^ model:eiiv db-hl:70 tone:n tubing: 25MM BATTERY:675

161

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTRCL

IKHZ GAIN DB

MPO. RANDOM NOISE

INPUT LEVEL« DB

OUTPUT LEVEL DB

MEASUREMENTS St/ITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN OB

HARMONIC DIST

aiNPUT LEVEL OB

50 0 HZ %

700 HZ %

900 HZ %

MAX DIST %

FREQ OF MAX OIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NG INPUT

65 OB INPUT

BATTERY VOLTAGE

01-184 01-185 OI-186

2300-2 23029 23044

FEB 25. 1975

54 ,0

74.0

118.5

52.0

75.0

118.0

52.0

74.0

117.5

51.0

60.0 70.0

4 5

1 2

0 0

5 20

530 18C0

43.0

N«M.

2.0

2.0

1 .33

52.0(FULL

)

60.0 70.0

5 9

1 2

0 0

5 23

500 1750

44. 0

N.M.

2.3

2.3

1 .33

50 .0

6 0.0 70.0

4 6

1 2

0 0

5 12

540 1780

44. 0

N.M.

2.0

2.0

1 .33
2 3 4 ' 5 6 7 8 9 1000 2 3 4 9 * FREQUENCY IN HERTZ

FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
CTICON

MODELrSllV DB-HL:7C T0NE:N tubing; 35MM BATTERY:675

163

CODE

SERIAL « DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO, RANDCM NOISE

INPUT LEVEL» DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

aiNPUT LEVEL DB

SCO HZ %

700 HZ %

900 HZ %

MAX DIST %

FREQ OF MAX DIS

S/N RATIO DB

IKhZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

01-187 01-188 OI-189

12385 13314 13337

MAR 3, 1975

54.0

74.5

118.5

51.5

76.5

118.0

52.

C

75.0

118.0

51 .5

60.0 70.0

6 8

1 1 0 0

6 16

500 1775

-44.5

N.M.

1 .8

1.8

1 .38

50.0

60.0 70.0

4 5

1 1 0 0

5 23

520 1840

45. 5

N.M.

1.6

1.6

1 .35

52. 0{ FULL)

60.0 70.

C

5 7

1 1 0 0

5 10

SCO 1875

44.0

N.M.

1.9

1 .9

1 .35
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
OTICON OE

M0DEL:E16U T0NE:N TUBiNG:25MM BATTERY:675

CODE

SERIAL « DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO. RANDCM NOISE

INPUT LEVEL. OB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN OB

HARMONIC DIST

aiNPUT LEVEL DB

SCO HZ %

700 HZ %

900 HZ %

MAX DIST %

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

0I-19C OI-191 OI-192

4108315 41C8346 4108520

FEB 25, 1975

44,0 45.5 44 . C

74,0

112.0

74.5

1 13.5

74.0

112.5

44.C(FULL)

60.0 70.0

5 8

1 2

0 0

5 8

500 500

43.5

N.M.

.8

.8

1 .40

45. 5 (FULL)

60.0 70.0

5 9

1 2

0 0

5 9

500 5CC

44.5

N.M.

.8

.8

1.4C

44.0(FULL)

60.0 70.0

5 1 1 1 3

1 1 5 1 1 50 0 50 0

42.5

N.M.

.8

.8

1 .40
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
OTICON OE

MODEL:EieP DB-SPL:137 tone:n TUBING:25MM BATTERY:675

CODE

SERIAL » DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO, RANDOM NOISE

INPUT LEVEL. DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

1KH2 GAIN DB

HARMONIC DIST

cDINPUT LEVEL DB

5G0 HZ %

700 HZ X

900 HZ %

MAX DIST %

FREQ OF MAX DI S

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

01-193 OI-194 OI-195

10880 10893 10953

FEB 25. 1975

70.5

72.0

130 .0

71 .5

71.0

1 29. 0

71,5

69.5

130.0

63.0

60.0 70.0

5 7

1 6

1 4

5 7

50 0 500

47. 5

N. M.

2.6

4.5

1 .35

60.5

60.0 70.0

2 5

1 5

0 3

2 6

500 790

45.5

N.M.

2.9

4. 5

1.33

61.5

60.0 70.0

2 4

1 4

0 3

3 5

2250 1110

46. C

N.M.

2.8

4.5

1 .33

OTICON

M0DEL:37SPPX tone:h receiver:cfd-8 BATTERY:502

CODE

SERIAL * DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO. RANDOM NOISE

INPUT LEVEL* DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VCLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

ffllNPUT LEVEL DB

500 HZ X

700 HZ %

900 HZ %

MAX DIST X

FREQ OF MAX DI S

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 UB INPUT

BATTERY VOLTAGE

01-196 OI-197 01-198

143890 144374 145281

APR 22, 1975

71.0

76 .0

130.5

70.5

72.5

131.0

69.0

77.0

130.0

58.5

60.0 70.0

2 2

3 4

4 6

4 6

900 900

40.0

N.M*

3.5

14.5

1 .43

57.5

60.0 70.0

2 2

3 5

2 6

3 6

700 900

39.0

N.M.

3.5

12.4

1 .43

57.5

60.0 70.0

2 2

3 4

4 4

4 5

900 1045

38.5

N.M.

3.5

12.8

1 .43
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
OTICON

model:380SI tone:none RECEIVER:AFM8 battery:5C2

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPOt RANDOM NOISE

INPUT LEVEL. DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN OB

HARMONIC DIST

aiNPUT LEVEL DB

50 0 HZ %

700 HZ X

900 HZ %

MAX DIST %

FREQ OF MAX 01 S

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

OI-199 01-200 OI-201

152229 155034 155C61

APR 22. 1975

58*0

79 .5

125.0

57.5

80.5

125.5

59 . 5

80 .0

125.5

55.0

60.0 70.0

4 7

3 8

4 12

4 15

900 1360

47.5

N.M.

5.1

5.1

1 .44

54. 5

60.0 70.0

4 8

3 10

4 10

4 15

500 1210

47.0

N.M.

4.9

4.9

1.44

55. 5

60.0 70.0

1 4

1 7

1 12

3 18

133C 1140

49.0

N.M.

5. 8

5.8

1 .44
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
CTICON

M00EL;565SZ-LDC OB-SPL:120 T0NE:H tubing: 25MM BATTERY -.675

CODE

SERIAL #

DATE

MEASUREMENTS ^ITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO. RANDOM NOISE

INPUT LEVEL. DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

ffllNPUT LEVEL DB

500 HZ %

700 HZ X

900 HZ %

MAX DIST %

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

01-202 OI-203 OI-204

23236 20218 26447

FEB 25, 1975

41.5

70.5

106.5

43.0

68.0

106.0

41 .C

69.

C

105.0

32.0

60.0 70.0

3 2

2 1

1 1 3 2

SCO 500

37.5

N. M.

1 .9

1 .9

1 .36

33 • 5

60.0 70.0

3 2

1 1

1 1 3 2

500 SCO

37.5

N.M.

2.0

2.0

1 . 38

30.5

60.0 70.0

2 1 2 1

1 1 3 2

1835 1835

38.0

N.M.

1 .9

1.9

1 .35
FREQUENCY IN HERTZ
PHONIC EAR SPEC OB 175

M0DE<_:HC 527 LN £ RESPONSE AV:7 TONElL RECE I VER : AT 1 6N BAT: INT

CODE HC-CCl rtC-OOa HC-003

SERIAL » 104336 10^355 L0438C

DATE JUN 16. 1975

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB 59.0 64.5 65.0

MPO, RANDOM NOISE

INPUT LEVEL. DB 77.5 76.0 77.

C

OUTPUT LEVEL DB 124.5 126.0 126.5

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

aiNPUT LEVEL

500 HZ

700 HZ

900 HZ

MAX DIST

FREQ OF MAX DIS

S/N RATIO DB

IKhZ SIGNAL

S/HUM RATIO

IKHZ SIGNAL

BATTERY DRAIN,

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

DB

%

%

%

%

DB

MA

59.0 (FULL ) 60.0 70.0

2 6

3 8

5 1 1 5 1 1 900 900

40.5

N. M.

******

64. 5( FULL)

60 70 .0

8

3

8

8

900 900

40.5

N.M. *****

***** ******

65.0(FULL)

60 .0

3

6

6

70. 0 6

6

7

7

900 900

39.0

N.M . *****

***** ******

THE HEARING AID HAS AN INTERNAL RECHARGEABLE BATTERY. THUS THE

DRAIN COULD NOT BE OBTAINED.

BECAUSE THESE HEARING AIDS HAVE NO EXTERNAL VOLUME CONTROL

CONTROL. ^ND BECAUSE THE INTERNAL CONTROL REDUCES THE

SATURATION LEVEL AS WELL AS THE VOLUME, THE GAIN COULD NOT BE

REDUCED SO THAT THE OUTPUT LEVEL WAS 12 DB BELOW SATURATION

WITH 60 DB IN. INSTEAD THE FULL SETTING OF THE INTERNAL CONTROL

WAS USED. THE ACTUAL OUTPUT LEVEL WITH 60 DB IN FOR THE THREE

AIDS WAS 120, 124. AND 124 DB.

177
PHONIC EAR SPEC OB

MODELCHC 527 LP S RESPONSE AV:7 TONE:L R ECE I VER : AT 1 6F BAT: INT

178

CODE

SERIAL * DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO» RANOCM NOISE

INPUT LEVEL. DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VCLUME

CCNTRCL SETTING

IKHZ GAIN DB

HARMONIC CIST

aiNPUT LEVEL OB

SCO HZ X

700 HZ %

90G HZ %

MAX DIST %

FREQ OF MAX DI S

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO OB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

HC-C04 HC-005 HC-0C6

104269 104418 10442R

JUN 16, 1975

70.0 67. 5 71.0

75.0

131 .0

76. 0

131.5

75. C 131.5

7 0.0 (FULL > 60.0 70.0

2 7

4 7

0 0

4 7

700 700

4 1.5

N.M. *****

***** ******

67.5(FULL)

6C.0 70.0

1 3

3 4

1 1 3 6

700 1210

40.5

N.M. *****

***** ******

71 . C(FULL)

60.0 70.

0

1 4

3 6

0 1 6 9

1230 1230

4 1.5

N.M. *****

***** ******

THE NOTES FOR THE PRECEEDING MODEL APPLY ALSO FOR THIS ON^E.

THE OUTPUT FOR THE THREE INSTRUMENTS WITH 60 DB IN IS 128.5.128,

AND 129.5.
FREQUENCY IN HERTZ
PHONIC EAR SPEC OB

MODEL :HC527LW S RESPONSE AV;7 TONEZL RECE I VER : AT 1 6W BAT: INT

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VOL CONTROL

IKHZ GAIN DB

MPOt RANDOM NOISE

INPUT LEVEL, DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

aiNPUT LEVEL DB

500 HZ X

700 HZ %

900 HZ %

MAX DIST %

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN* MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

HC-007 HC-008 HC-009

104304 104325 104458

JUN 16, 1675

62.5 62.0 61.5

81.0

123.5

72.0

123.5

74.0

122.5

62.5(FULL ) 60.0 70.

C

3 6

4 6

4 8

4 a 90 0 90 0

42.5

N. M.

***

62. 0( FULL

)

60.0 70.0

2 7

4 8

4 8

4 8

900 900

41.0

N.M.

61 . 5(FULL)

60. C 70.0

3 7

4 7

4 8

4 8

90 0 90 0

40.0

N.M.

***** ******

THE NOTES FOR MODEL HC527LN ALSO APPLY TO THIS MODEL.

THE OUTPUT WITH 60 DB IN FOR THE THREE INSTRUMENTS IS 120. 120.5,

AND 120 Oe.
181
182
PHONIC EAR SPEC OB

MODEL :HC527SEN S RESPONSE AV:7 RECE I V ER : AT 1 6N BATTERYIlNT

CODE

SERIAL H

DATE

MEASUREMENTS WITH

FLLL VOL CONTROL

IKHZ GAIN DB

MPO, RANDOM NOISE

INPUT LEVEL, DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VCLUME

CONTROL SETTING

IKHZ GAIN DB

-ARMONIC CIST

aiNPUT LEVEL OB

500 HZ %

700 HZ %

900 HZ X

MAX DIST %

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

HC-OlO HC-Cll HC-G12

105484 105510 10^564

JUN 16, 1675

62.5 6:^.5 62.5

71.0

125.

C

T5. 0

123.5

72. C 124.5

6 2. 5 (FULL

)

60.0 70.0

2 4

4 6

4 7

4 7

9C0 900

41.0

N. M.

*****

63.5(FULL)

60.0 70-0

2 4

3 5

5 6

5 6

900 900

39.0

N.M. *****

***** ******

62. 5(FULLX

60.0 70.0

2 4

4 5

5 7

5 7

90 0 9C0

41.0

N.M . *****

***** ******

THE NOTES FOR MODEL HC527LN ALSO APPLY TO THIS MODEL.

THE OUTPUT WITH 60 DB IN FOR THE THREE INSTRUMENTS IS 122.5,122,

AND 122 DB.
184

I
185
PHONIC EAR SPEC OB

M0DEL:HC527SEP S RESPONSE AV:7 RECEI VER : AT 1 6P BATTERYCINT

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO, RANDOM NOISE

INPUT LEVEL. DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CCNTRCL SETTING

IKHZ GAIN DB

HARMONIC DIST

©INPUT LEVEL DB

500 HZ %

70 0 HZ %

900 HZ X

MAX DIST X

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

HC-013 HC-014 HC-C15

105483 1C5539 105565

JUN 16. 1975

69 .0 70.5 68.5

75 .5

131 . 5

73.0

1 30.5

70. 5

13C.5

69.0 (FULL)

60.0 70.0

2 5

6 1 1

I 1 6 11

700 700

42.5

N.M.

***** ******

70.5(FULL

)

60.0 7C.0

2 5

5 8

0 1 5 8

700 700

42.0

*****

***** ******

6 8. 5 (FULL)

60.0 70.0

2 4

4 6

1 0

4 6

70 C 7C0

42. C

N.M. *****

***** ******

THE NOTES FOR MODEL HC527LN ALSO APPLY TO THIS MODEL.

THE OUTPUT WITH 60 DB IN FOR THE THREE INSTRUMENTS IS 128.5. 128

AND 128 DB.

PHONIC EAR

M00EL:HC527SEW

SPEC OB

S RESPONSE AV:7 RECEI VER : AT 1 6W BATTERYtiNT

188

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VOL CONTROL

IKHZ GAIN OB

MPO. RANDCM NOISE

INPUT LEVEL. DB

OUTPUT LEVEL CB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

aiNPUT LEVEL OB

500 HZ %

7C0 HZ %

9C0 HZ X

MAX DIST %

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

HC-0 16 HC-017 HC-018

105550 105660 105614

JUN 16« 1975

61.5 63.0 59. 5

74.0

121.5

75.5

1 23.0

74.0

121.5

6 1 .5(FULL ) 6C.0 70.0

3 6

5 8

5 9

5 9

9C0 900

41.0

N. M.

******

63.0{FULL)

60. C 70.0

3 5

5 7

6 9

6 9

900 900

41.5

N.M.

**4c4c*

««*:(( :(c*

59.5(FULL)

60. C 70.0

2 4

6 7

6 8

6 8

9C0 900

4C.5

N.M .

*4:*** *****

*«*:tc««

THE NOTES FOR MODEL HC527LN ALSO APPLY TO THIS MODEL.

THE OUTPUT WITH 60 DB IN FOR THE THREE INSTRUMENTS IS 119.5, 120,

AND 118.5 OB*
189
190
QUALITONE DIR OE

model:csd T0NE:N TUBING:25MM BATTERY:S76

CODE

SERIAL M

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN OB

MPO» RANDOM NOISE

INPUT LEVEL* DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

1KH2 GAIN DB

HARMONIC DIST

©INPUT LEVEL DB

500 HZ X

700 HZ %

90 0 HZ %

MAX DIST %

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

QU-238 QU-239 QU-240

65314 65318 65373

MAY 28t 1975

45 .0 42.5 46.5

79 .5

105.0

82.0

106.0

81.0

105.

5

34,0

60 .0

8

2

18

50 0

70.0

4

1

14

500

33.5

60.0 70.0

6 2

37. 5

SCO 5C0

60 . 06

116

5C 0

70 . 0 2

1

12

5C 0 40.5

N. M.

38.5

N.M.

43.5

N.M.

.3

.3

1 .56

.4

.4

1 . 56

.4

.4

1 .56
±t

±~

f-j-i i r «4i

7ITI'

tilt

;!!-;

r!-l:'i-

•»

:^::4n: it;_ ijrth i4:t-•-'i-j. [:-" -n-

".1

~-—hIf —{

V

;iij||[!i-t

/t1 /'

r

Vj

192

i

alt i

i

s

1

1 n

t|J I- Si

/

-

: 1

i

i

-n-

'_-}

r •

,-a

n

urn

-. :: r...i -Iri-iT-iL, - uf : i

i«

if ]:

-t

I i

i-'i

I !

" '

!

i

'

1 : i I i

11

-1

\ -uj

: > ,

-

6

1

' 8 'I300 l1 lliili

i

'

;

'

:

ilins \V

'ilir 10.1 tf.

I liiMll 4

i;

; II

3 4 5 FREQUENCY IN HERTZ

FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
QUALITONE CROS EG

model:snec tone:n TUBING:42MM BATTERY:S76

193

CODE

SERIAL » DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN D8

MPO, RANOCM NOISE

INPUT LEVEL. DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VCLUME

CONTROL SETTING

IKHZ GAIN DB

S/N RATIO DB

2KHZ SIGNAL

S/HUM RATIO DB

2KHZ SIGNAL

BATTERY DRAIN. MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

QU-241 QU-242 OU-243

17187 17189 17297

JUN 10. 1975

41.5 43.0 42.0

86.0

122.5

85.5

122. 0

86.0

124,0

36.5

49.5

N. M.

2.0

2.0

1 .55

38.0

48.0

N.M.

2.0

2.0

1 .55

37.0

46. 0

N.M.

2.0

2.0

1.55

QUALITONE OE

MODELITPF T0NE:N SCR1&2:IN TUBING: 25MM BATTERY:S76

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO, RANDOM NOISE

INPUT LEVELi DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC CIST

ffllNPUT LEVEL DB

500 HZ X

700 HZ %

900 HZ X

MAX OIST X

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN* MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

QU-2A4 QU-245 QU-246

1733 1741 1747

MAY 28, 1975

62*5 61.5 62. C 76 • 0 79 • 0 78 • 5

126.5 125.5 126.5

54.0 54.0 53.5

>0 .0 70.0 60.0 70.0 60 . 0 70 •

0

7 5 4 4 6 9

3 3 1 7 2 a

2 4 1 4 2 2

7 5 4 I 0 6 1 1 500 1270 500 800 500 600

41.0 41.5 40.C

N.M. N.M. N.M.

.9 1 .0 I. 1 2.0 2.0 1 .9

1 .56 1 .56 1 .56

/
FREQUENCY IN HERTZ
qualitone

model:tsp tone:none tubing:30mm

OE 197

BATTERY :S76

CODE

SERIAC #

DATE

MEASUREMENTS WITH

FLLL VCL CONTROL

IKHZ GAIN DB

MPO, RANDOM NOISE

INPUT LEVELi DB

OUTPIdT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

aiNPUT LEVEL DB

SCO HZ %

70C HZ %

900 HZ X

MAX DIST %

FREQ OF MAX DI

S

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NC INPUT

65 DB INPUT

BATTERY VOLTAGE

QU-247 QU-248 QU-249

22845 22889 22896

MAR 26, 1975

58.5 57. G 57.0

80 .0

129.0

81.0

128.5

82.0

128.5

58.5(FULL

)

61.0 71 .C

4 3

2 3

3 5

4 8

5CC 1840

43.0

N . M.

1.3

3.6

1 .57

57.C(FULL)

61.5 71.5

12 14

2 6

4 7

12 1 4

500 500

42. 5

N.M .

1 .5

3.2

1 . 57

57. C( FULL)

61.0 71.0

6 5

2 4

2 4

6 13

500 1780

44.0

N.M.

.8

2.8

1 .57
FREQUENCY IN HERTZ
QUALITONE BI EG

M0DEL:TSPNB TCNE:N TUBING:35MM BATrERY:S76

CODE

SERIAL » DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPOi RANDCM NOISE

INPUT LEVELi DS

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CCNTRCL SETTING

IKHZ GAIN DB

HARMONIC DIST

cDINPUT LEVEL DB

500 HZ %

700 HZ %

900 HZ %

MAX DIST %

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

QU-250 QU-251 QU-252

7594 7595 7660

MAR 27, 1975

62.0 64, 5 66. 5

77-5

130 .0

76. 0

1 29.5

73. C 129.0

60.0

60.0 70.0

8 10

6 8

4 9

12 16

564 564

47.5

N. M.

1 .0

3.5

1 .55

61.0

60.0 70.0

12 15

6 10

3 6

12 17

500 670

49. 5

N.M.

1.2

3.7

1 . 55

6 1.5

60.0 70.

C

45 45

12 29

5 14

45 47

50 C 76 0

49.5

N.M.

1 .2

3.5

1 .55

BOTH MICROPHONES WERE LEFT CONNECTED AND PLACED WITHIN

ONE-HALF INCH OF EACH OTHER FOR THE TEST.
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
QUALITONE OE

M0DEL:TSS T0NE:N TUBING:25MM battery: S76

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO. RANDOM NOISE

INPUT LEVEL, DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN OB

HARMONIC DIST

JDINPUT LEVEL DB

500 HZ X

700 HZ X

90 0 HZ %

MAX DIST %

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

QU-253 QU-254 QU-255

55463 55501 55571

MAY 29, 1975

44.5 45.0 43.5

87.5

121 .5

86. C 121.086,5

120.5

4 4. 5 {FULL

)

67.0 77.0

3 6

1 1 0 1 4 45

1200 1480

44.5

N.M.

2.5

2.5

1 .56

45. 0( FULL)

64. C 74.0

5 11

1 2

1 1 5 21

500 1480

44. 0

N.M.

2.3

2.3

1 . 56

43.5(FULL)

68.0 78.0

4 9

1 2

1 1 5 25

1 2C 0 1 50 0

43.5

N.M .

2.3

2.3

1 .56

QUALITONE OE 203

model:ufc tonexnone tubing:25mm battery :S13

CODE

SERIAL « DATE

QU-256

40260

QU-257

4031 1 MAY 29, 1975

QU-258

40327

MEASUREMENTS WITH

POLL VCL CONTROL

IKHZ GAIN DB 33.0

MPOt RANOCM NOISE

INPUT LEVEL, DB 84.0

OUTPUT LEVEL DB 109.0

31.0

85.0

1 06. 0

33.0

84.0

1C9 .5

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

1KH2 GAIN DB

HARMONIC DIST

aiNPUT LEVEL

SCO HZ

700 HZ

900 HZ

MAX DIST

FREQ OF MAX DI

S

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN« MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

OB

X

X

X

X

33.0 (FULL

)

64.0 74.0

2 2

1 1

1 1 3 15

1370 2470

41 .0

N.M.

• 4

.4

1 .56

3 1 . 0( FULL ) 62.0 72.0

2 2

2 2

Z 2

3 24

1540 2460

40 • 0

N.M.

• 4

• 4

i .56

33.0(FULL)

65.0 75.0

3 3

1 1

1 1 3 22

5CC 1830

4 1.5

N.M.

• 4

1 .56
•

FREQUENCY IN HERTZ
RADIOEAR OB

MODEL:980 SC:i,2.4,5t7» IN 3.6 OUT RECEIVER:M96 BATTERY:40l

CODE RA-232 RA-233 RA-234

SERIAL * 571N9 571P1 572N0

DATE APR 30» 1975 MAR 10* 1975

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB 72.5

MPO. RANDOM NOISE

INPUT LEVEL. DB 84.0

OUTPUT LEVEL DB 135.0

71 . 0

75.0

134.0

70.5

75.0

134.5

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

ffllNPUT LEVEL

50 0 HZ

700 HZ

900 HZ

MAX DIST

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN. MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

DB

X

%

X

X

65.0

60.0 70.0

5 10

4 10

4 9

5 10

50 0 700

44.0

N.M.

5.9

8.4

1 .43

63.0

60.0 70.0

5 8

3 7

2 5

5 8

500 500

43.0

N.M.

6.1

7.0

1.41

64. C

6 0.0 70.0

4 10

3

2

4

50 0

42.0

N.M.

6.2

8.7

1.40

8

4

10

500

RA-232. SERIAL # 571N9, ORIGINALLY HAD HIGH DISTORTION

WHICH ORIGINATED IN THE RECEIVER. THREE REPLACEMENT RECEIVERS

WERE OBTAINED. AND THE DISTORTION CHECKED WITH THESE. THE

DATA ARE SHOWN BELOW. THE ORIGINAL RECEIVER IS NO. 4. THE

DATA ABOVE ARE WITH RECEIVER 2 . RCVR 1 2 3 4

LEVEL 60 70 60 70 60 70 60 70

FREQ

50 0 11 65 5 10 1 5 10 62

TOO 9 51 4 10 1 6 7 38

900 11 43 4 9 1 7 13 66
FREQUENCY IN HERTZ
RADIOEAR DIR OE

model: 1030 LF SC:iN AVC SCOUT TUBING:25MM eATTERY:S76

CODE • SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPOt RANDCM NOISE

INPUT LEVEL, DB

OUTPUT LEVEL 08

MEASUREMENTS WITH

REDUCED VOLUME

CCNTRCL SETTING

IKHZ GAIN DB

HARMONIC DIST

SINPUT LEVEL DB

SCO HZ X

700 HZ %

9C0 HZ %

MAX DIST %

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

DATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

RA-235 RA-236 RA-237

54<*03 54775 55458

APR 21, 1975

48.0 48.0 50.

C

80.0 £2.0 79.5

121.0 121.5 121.5

47. 5

60.0 7C.0

C 3

1 1 2 2

2 24

900 1680

38.0

N. M .

1 .7

1.7

I .56

47.5

60.0 70.0

3 6

1 3

1 2

3 2 0 500 1670

37. 5

N .M .

1 .7

1.7

1 . 55

48. C 60.0 70.0

4 4

2 1 1 1 5 21

1580 1640

38 . 5

N . M .

1 .8

1.8

1 .55


RADIOEAR EG

model: 1040 LF:CCW GAIN:CCW TU8ING:35MM BATTERY:S76

210

CODE

SERIAL * DATE

MEASUREMENTS WITH

FLILL VCL CONTROL

IKHZ GAIN DB

MPO, RANDOM NOISE

INPUT LEVEL, DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN OB

HARMONIC DIST

aiNPUT LEVEL DB

500 HZ X

700 HZ %

900 HZ %

MAX DIST %

FREO OF MAX DI

S

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NC INPUT

65 DB INPUT

BATTERY VOLTAGE

RA-238 RA-239 RA-240

13850 14013 14280

APR 24t 1975

58.0

79.0

127.0

58.0

78 .0

1 27. 0

58.5

75.0

127.

C

53.0 54.0 52.0

1.0 70. C 60.0 70.0 60.0 70.0

2 4 3 6 3 8

1 5 1 5 1 6

A 7 4 8 3 10

10 47 1 1 47 13 29

;40 1280 12 20 12 20 1350 1270

45.0 46.5 46.5

N.M. N.M. N.M .

1.0 1.1 1 . 1 2.5 2.6 2.8

I .55 1 .55 1 .55
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
RADIOEAR OE

model: 1050 LF SC:IN OUTPUT SCIlN TUBlNG:25MM BATTERY: S76

212

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO, RANDCM NOISE

INPUT LEVEL. DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

©INPUT LEVEL DB

500 HZ %

700 HZ %

900 HZ %

MAX DIST %

FREQ OF MAX DIS

S/N RATIO OB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

RA-241 RA-242 RA-243

86368 87444 88187

FEB 28, 1975

67.0 64.0 62.5

73.0 71.0 70.5

127.0 127.5 126.5

55.0 56.0 54.0

>0.0 70 .0 60.0 70.

0

60.0 70.

G

6 5 4 1

3

6 10

3 3 1 5 3 5

1 0 1 2 1 1 7 5 4 13 6 12

560 500 500 500 575 575

48. 0 44.5 43.5

N.M: • N.M. N.M.

• 9 1 . 0 1 .0

2. 5 2.9 2.8

1 . 54 1 .54 1 .54
FREQUENCY IN HERTZ
REXTON OE

M00EL:4112 PftlMO CE TONE:H COMP:N TUBING:25MM BATTERY:

CODE

SERIAL #

DATE

MEASUREMENTS ln/ITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO, RANDOM NOISE

INPUT LEVEL. DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

1KH2 GAIN DB

HARMONIC DIST

aiNPUT LEVEL DB

500 HZ %

700 HZ X

900 HZ X

MAX DIST X FREQ OF MAX OIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

RE-001 RE-CC2 RE-0C3

15896 15921 15972

FEB 27, 1975

49 . 0

7 1 .0

114.5

44,5

71.0

113.5

40.0

74.0

113.0

40.5

60.0 70.0

3 8

1 2

0 1 4 8

1580 500

42.5

N.M.

1 . 1

1 . 1

1 .55

39.0

60.0 70.0

2 2

1 1 0 0

4 2

1610 500

42.5

N.M.

1 . 1

1 . 1 1 . 55

38.5

60.0 70.0

2 4

0 1 1 1 5 4

1510 500

39.0

N.M.

1 . 1

1 • 1 1 ,55
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
REXTON OB

M0DEL:4134 SUPERMASTER T0NE:N receiver: AFD4 BATTERY:40 1 CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN 08

MPO. RANDOM NOISE

INPUT LEVEL, DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC CIST

SINPUT LEVEL DB

50 0 HZ %

700 HZ %

90C HZ %

MAX DIST %

FREQ OF MAX DI S

5/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

RE-004 RE-005 RE-006

3412 3480 5006

MAR 7, 1975

68.5

68.0

125,0

67. 0

69.5

124.Q

67. C

67.0

123.

C

52.5

60.0 70.0

3 6

3 5

4 6

4 6

900 900

38.5

N.M.

1-3

2.5

1 .40

51.0

60-0 70.0

1 6

1 3

2 6

5 8

2000 1220

39. 0

N.M.

1.2

2.5

1.40

50. C 60.0 70.0

1 4

1 3

2 6

6 a 2040 1840

37.5

N.M.

1.0

2.5

I .39
2 3 A 56789 1000 Z 3 4 S 6 FREQUENCY IN HERTZ

FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
«EXTON OE

MCDEL:4136 CnMP:N(CCW) tubing: 25MM BATTERY:675

218

CODE

SERIAL « DATE

MEASUREMENTS WITH

FULL VCL CONTROL

1KH2 GAIN DB

MPOt RANOCM NOISE

INPUT LEVEL* DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CCNTRCL SETTING

IKHZ GAIN DB

HARMONIC CIST

aiNPUT LEVEL DB

SCO HZ %

700 HZ %

900 HZ %

MAX DIST %

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NC INPUT

65 DB INPUT

BATTERY VOLTAGE

RE-007 RE-C08 RE-009

4877C 49143 49153

MAY 14, 1975

51.5 52.5 53.0

81.0 80.5 79.0

124.0 124.0 124.0

51 .5(FULL

)

60.0 70.0

0 4

1 2

2 2

7 10

1830 1250

39.5

N.M.

.8

1 .8

1 .33

52. 5( FULL

)

61.5 71.5

4 7

2 2

1 1 4 1

4

500 1265

41.0

N.M.

.7

1.0

1 .33

53. 0<FULL)

60. C 70.0

0 4

1 1

1 2

4 16

1900 1240

4 1.5

N.M.

.7

2.C

1 .33
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
REXTON DIR OE

M0DEL:4137 C0MP:N(CCW) tubing: 25MM BATTERY:675

220

CODE

SERI AL

DATE

RE-0 10

1 30 5 1 4

RE-Cl

I

130519

MAY 14. 1975

RE-012

132023

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB 39.5

MPO. RANDOM NOISE

INPUT LEVEL* DB 81.0

OUTPUT LEVEL DB 114.5

42.5

78.0

1 14.5

46.0

76.0

I 15.

C

MEASUREMENTS WITH

REDUCED VCLUME

CONTROL SETTING

IKHZ GAIN OB

HARMONIC DIST

©INPUT UEVEL

50 0 HZ

7C0 HZ

900 HZ

MAX DIST

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN. MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

DB

%

%

X

%

39.5{FULL

)

63.0 73.0

0 6

0 3

1 3

10 25

1520 1520

41.0

N.M.

1.2

1 . 2

1 .38

41,5

60.0 70.0

2

I

1

1 3

1510 15 10

42.5

N.M.

1 .3

1.3

1 .36

46. OCFULL)

60.0 70.0

0 5

0 2

0 1 6 15

1435 1435

44.0

N.M.

1 .4

1.4

1 .33

FREQUENCY IN HERTZ
SHALAKO SPEC OE

model:colorsonic i421 tone:none TUBING:25MM BATTERY:675

223

CODE

SERIAL

DATE

SH-0 0

1

B01C93

SH-002

C01106

JUN 17, 1975

SH-003

DOl 16C

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB 20.5

MPO, RANDOM NOISE

INPUT LEVEL, DB 81.0

OUTPUT LEVEL DB 104-.0

22.0

77.0

108.0

25.0

76. 0

108.

C

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

ffllNPUT LEVEL

500 HZ

.700 HZ

900 HZ

MAX OIST

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO

IKHZ SIGNAL

BATTERY DRAIN,

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

DB

%

%

%

%

DB

MA

20 .5(FULL)

61.0 71.0

3 2

0 0

0 1 18 13

1740 1740

32.5

N«M.

1.3

1 .3

1 .32

22.G(FULL)

61 .0 71.0

2 2

1 3

1 3

11 6

1690 J690

29. 0

N.M.

1 .4

1.4

1.32

25.C(FULL

)

61.0 71.0

3 4

2 6

3 3

5 9

1150 770

32. 0

N.M.

1 .4

1.4

1 .32

S/N 2KHZ 33.0 38. 0 44.0
FREQUENCY IN HERTZ
SHALAKO SPEC OB 225

model: COLCRSONJC 1511 TONE:SEE BELOW REGE I V ER : CF08 DAT TERY : MN 1 5 0

0

CODE 5(4^004 SH— 005 SH—0 06

SERIAL # C 04 4 5

DATE JUN 17. 1 975

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB 14.5 28. C MPOt RANDOM NOISE

INPUT LEVEL. DB 79 « 0 8i .0 78 . 0

OUTPUT LEVEL DB 108.0 113.5 115.5

MEASUREMENTS WITH

REDUCED VOLUME

CCNTRCL SETTING

IKHZ GAIN DB 1 4 . 5{ FULL ) ***«*( FULL

)

28. C < FUl

HARMONIC DIST

aiNPUT LEVEL DB 60.0 70.0 63.0 73.0 6C « 0 70 .

0

50 0 HZ % 0 2 0 1 0 8

700 HZ X 0 1 1 1 2 4

900 HZ % 1 6 0 0 2 4

MAX DIST % 15 16 10 16 5 8

FREQ OF MAX DI S 1270 1290 500 500 1250 500

S/N RATIO DB

IKHZ SIGNAL 14.5 20 .5

S/HUM RATIO DB

IKHZ SIGNAL N.M. N.Ma N.M.

BATTERY DRAIN, MA

NO INPUT 4.8 6.0 4,8

65 DB INPUT 4.8 5.0 4.8

BATTERY VOLTAGE 1 .50 1.50 1 .50

BECAUSE OF THE SPECIAL NATURE OF THIS INSTRUMENT, THE AID

WAS TESTED AS IT CAME, WITHOUT FURTHER CHECKING OF THE TONE SCREWS.

THE SIGNAL FOR SH-005 WAS BELOW THE NOISE LEVEL AT IKHZ.

THE GAIN AT 500HZ WAS 18 DB AND THE S/N AT 500HZ WAS 27.5 DB

.
226
227

FREQUENCY IN HERTZ
SIEMENS OE

model:22AVC avc:on TUBING:22MM BATTERY:675

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VOL CONTROL

IKHZ GAIN DB

MPOt RANDOM NOISE

INPUT LEVEL* DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VCLUME

CONTROL SETTING

IKHZ GAIN DB

hARMOMC DIST

aiNPUT LEVEL DB

500 HZ X

700 HZ X

900 HZ X

MAX OIST X

FREQ OF MAX Dl

S

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NC INPUT

65 DB INPUT

BATTERY VOLTAGE

SI-139 SI-140 SI-141

129100 130498 129737

FEB 19, 1975

46.5

69.0

109 .0

37.5

60.0 70.0

6 6

0 0

1 1 6 6

5C0 SCO

46.5

N.M.

1 .9

1 .9

1 .33

46.0

74. 0

111.0

40.0

60.0 70.0

6 7

I 0

1 0

6 7

500 500

4a..o

N.M.

1.9

1.9

1 .33

46.5

73.0

110.5

39. 5

60.0 7C.0

6 6

I 0

1 0

6 6

50 0 50 0

48.5

N.M •

1.9

1.9

1 .32
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
SIEMENS OE

MODEL :2A-PP-PC TONEJN PC:OFF TU8ING:25MM BATTERY:675

230

CODE

SERIAL 0 DATE MEASUREMENTS WITH FULL VOL CONTROL

IKHZ GAIN 08

MPO. RANDOM NOISE

INPUT LEVEL t OB

OUTPUT LEVEL OB

MEASUREMENTS WITH REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB HARMONIC DIST

aiNPUT LEVEL OB

500 HZ X 700 HZ X 900 HZ X MAX OUST < FREQ OF MAX 01 S/N RATIO Or IKHZ SIGNAL

S/HUM RATIO OB

IKHZ SIGNAL

BATTERY DRAIN, MA

NC .!^'PUT 6 5 Oe INPUT BATTFRV VOiTAG:;

SI-1A5 SI-143 SI-.144 116774 116885 116899

FEB 19. 1975

65.0 65.5 63.0

73.0

128.

5

72.5

127.0

73.0

128.0

56. 0 57.0 56.5

60.0 70.0 60 .0 70.0 60.0 70.0

8 J5 10 24 8 12 A 6 5 8 5 7

1 6 2 5 1 5

e 15 10 24 8 12

- A 500 500 500 50 0 50 0 42. S 46.5 46.0

N.M N.M. N.M.

2. 5 2.7 2.5

3. 2 3.3 3.0

1 . 37 1. 34 1.34
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
SIEMENS HP OE

M0DEL:^6H TONe:CW TUBING:25MM BATTERY:675

232

CODE

SER I AL

DATE

SI-145

140643

51-146

1 40654

MAY 22, 1975

51-147

140644

MEASUREMENTS WITH

FULL VCL CONTROL * IKHZ GAIN OB 19.5

MPO. RANDCM NOISE

INPUT LEVELf DB 82.5

OUTPUT LEVEL DB 123.0

20. 5

32.5

123.5

20.0

bS.O

123.5

MEASUREMENTS WITH

REDUCED VCLUME

CCNTRCL SETTING

IKHZ GAIN DB

S/N RATIO DB

2KHZ SIGNAL

S/HUM RATIO DB

2KHZ SIGNAL

BATTERY DRAIN. MA

NC INPUT

65 DB INPUT

BATTERY VOLTAGE

14.5

4 4.5

N.M.

1 •a

1 .8

1 .33

15.5

44.5

N.M.

I .9

1.9

1 .33

15.

C

45. 3

N.M .

1.8

1 .8

1 . 33

*Maximxmi setting possible without feedback.
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
SIEMENS OIR OE

M0DEL;32D AFC PC TONE:N PC:OFF TUBING:25MM BATTERY:675

234

CODE

SERIAL #

DATE

MEASUREMENTS ^ITH

FULL VCL CONTROL

IKHZ GAIN DB

MPOt RANDOM NOISE

INPUT LEVEL, DB

OUTPUT LEVEL DS

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC OIST

aiNPUT LEVEL DB

50 0 HZ %

700 HZ %

900 HZ %

MAX DIST %

FREQ OF MAX OIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

SI-148 SI-149 SI-150

10754 13441 12224

APR 16, 1975

44.0

90 .0

116.0

44.0

90.0

1 18.0

44.0

86. 0

1 1 5.C

44.0(FULL)

73.0 83.0

14 20

5 1 I 3 6

14 20

500 500

40.5

N.M.

1 .9

1.9

1 .33

44.0(FULL)

75.0 85.0

14 23

6 1 1 4 6

14 23

500 500

40.0

N.M.

1.6

1 . 8

1 . 33

44.0(FULL)

60.0 7C.0

11 18

4 12

2 5

1 1 18

50 0 50 0

37.5

N.M.

1 .9

1 .9

1 .33
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
SIEMENS OIR OE

M0DEL:340 SL LC PC:0FF(CW) tubing: 25MM BATTERY:675

237

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DS

MPOt RANDCM NOISE

INPUT LEVEL. DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL S^ETTING

IKHZ GAIN 08

HARMONIC DIST

aiNPUT LEVEL DB

500 HZ %

700 HZ %

900 HZ X MAX DIST %

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO OB

IKHZ SIGNAL

BATTERY DRAIN. MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

SI-151 SI-'152 SI153A

180C7 18197 27696

MAY 16, 1975

51.0 56.5 55.5

84.5

126.5

83.0

128. 0

84.0

127 .5

51.0(FULL) 55.0 55.5(FULL)

64.0 74.0 60.0 70.0 6 1.0 71.0

9 21 8 27 10 23

5 9 4 6 7 12

2 6 1 4 2 7

9 21 8 27 IC 23

SCO 500 500 500 50 C 50

C

40. 0 36. 5 44,0

N. M • N.M • N.M.

2. 2 2. 2 2.2

2. 8 2.8 2.8

1 . 33 1 . 33 1 .34

SI-153. SERIAL * 19579 , WAS CONSIDERED DEFECTIVE BECAUSE

OF SEVERE FEEDBACK.
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
SCMOTONE BI EG

M0DEL:35AX TONE:NONE TUBING:35MM BATTERY:S76

CODE

SERIAL * DATE

MEASUREMENTS WITH

POLL VCL CONTROL

IKHZ GAIN OB

MPO. RANDOM NOISE

INPUT LEVEL* 06

OUTPUT LEVEL OB

MEASUREMENTS WITH

REDUCED VOLUME

CCNTRCL SETTING

IKHZ GAIN D8

HARMONIC DIST

aiNPUT LEVEL DO

50 0 HZ %

700 HZ %

900 HZ X

MAX DIST X

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

SO-277 SO-278 SO-279

A69863X5a657 A69798X5856 1 A69852X58642

APR 30, 1975

53.0

77.0

123.0

53.5

80 .0

1 24.0

54.0

77.0

122 .C

51 .5 53.0 52. C

>0.0 70.0 60 . 0 70.0 60-0 70.0

5 10 6 13 6 14

1 3 3 7 1 3

1 2 3 6 1 3

5 10 6 1 3 6 14

500 500 500 SCO 50 0 50 0

49 .5 49.5 51 .0

N. M. N.M • N.M.

1 .9 1 . 8 1 .9

1.9 1. 8 1 .9

1 .56 1. 56 1.56

BOTH MICROPHONES WERE LEFT CONNECTED AND PLACED CLOSE

TOGATHER TO AVOID PHASE INTERFERENCE.
FREQUENCY IN HERTZ
SONOTONE CROS EG

M0DEL:35AZ TONEINONE TUBING;42MM BATTERY:S76

242

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO, RANDOM NOISE

INPUT LEVEL, DB

OUTPUT LEVEL DB

MEASUREMENTS KITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

S/N RATIO DB

2KHZ SIGNAL

S/HUM RATIO DB

2KHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

S0-28C SO-281 SQ-282

A6978aZ58397 A69861Z58623 A69779Z58659

JUNE 6, 1975

46.0

77.0

125.0

45.0

80.5

1 25.0

47.0

79.0

125.5

41.0

53.5

N.M.

2.0

2.0

1 .55

40. 0

54.0

N.M.

2.2

2. 2

1.55

42.0

54.

C

N.M.

2.4

2.4

1 .54
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
SONOTONE

MODEL :40-6 TONE rNONE TUBING: 35MM BATTERY: S76

244

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPOt RANDOM NOISE

INPUT LEVEL. DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VCLUME

CONTRCL SETTING

IKHZ GAIN DB

HARMONIC DIST

aiNPUT LEVEL DB

SCO HZ %

700 HZ %

9C0 HZ %

MAX DIST %

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO OB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

SO-283 SO-284 SO-285

31044 31053 31064

APR 3, 1975

53.0

80 .0

123.0

55.0

78.5

123.5

58. 0

79. 0

123.5

53.0(FULL) 52.5 55.5

60.0 70. C 60.0 70.0 6G.C 70.

C

3 4 2 3 3 3 13 13 13

2 4 2 2 2 1 3 22 2 10 3 16

500 1876 500 1780 500 1835

43.5 44.5 46.5

N.M. N.M. N.M.

3.0 2.9 2.9

3.0 2.9 2.9

1.55 1.55 1.55
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
SCNOTONE HP

model:50-2 tone:none tubing:42mm battery: S13

246

code SO-286 SO-267 SO-288

serial # 24047 24053 24082

DATE JUNE 9. 1975

MEASUREMENTS WITH

FULL VCL CONTROL * 1KH2 GAIN DB 14.0 11.0 14.5

MPO, RANDOM NOISE

INPUT LEVEL, DB 89.0 90.0 88.0

OUTPUT LEVEL DB 121.5 116-0 120.

C

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB 10.0 8.0 10.5

S/N RATIO DB

2KHZ SIGNAL 41.5 >36.5 41.5

S/HUM RATIO DB

2KHZ SIGNAL N.M. N.M. N.M.

BATTERY DRAIN, MA

NO INPUT .7 .7 .7

65 DB INPUT .7 .7 .7

BATTERY VOLTAGE 1.55 1.55 1.55

*Maxinrum setting possible without feedback.
FREQUENCY IN HERTZ
SONOTCNE

mooel:77s tone:none TUBING:25MM BATTERY:S76

OE 248

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTRCL

IKHZ GAIN OB

MPO. RANDOM NOISE

INPUT LEVEL, DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTRCL SETTING

IKHZ GAIN DB

HARMONIC DIST

SINPUT LEVEL DB

SCO HZ %

700 HZ X

900 HZ %

MAX DIST %

FR£Q OF MAX DIS

S/N RATIO OS

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NC INPUT

65 DB INPUT

BATTERY VOLTAGE

50^289 SO-290 SO-291

22561S 22570S 22594S

APR 2, 1975

54.5

86.5

124.5

55.5

85.0

1 24.5

53.5

83.0

124.

C

5 4. 5 (FULL )

6 1.5 71.5

2 6

1 4

1 4

3 19

1720 1735

44.0

N. M.

3.0

3.0

1 .55

55.5(FULL

)

60.5 70.5

3 4

3 4

2 5

3 23

1760 1815

44.5

N.M.

3.0

3.0

1 . 55

53.5(FULL)

60.0 70.0

2 3

1 2

2 2

2 16

900 1720

43.5

N.M.

3.3

3,3

1 .55
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
SONOTONE OB 250

MODeL:670BX TONE : F-N- N-P ; WHT MIC INSERT RECE I V ER : 4 1 2 1 RD BAT: 132

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO. RANDCM NOISE

INPUT LEVEL. DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

aiNPUT LEVEL DB

50 0 HZ %

700 HZ %

900 HZ %

MAX DIST %

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

SO-292 SO-293 SO-294

B6125 86390 B6428

MAY 2. 1975

84 ,0

73.0

142.5

74.0

60.0 70.0

10 16

5 9

3 4

10 16

500 500

47.5

N. M.

9.2

20.0

2.76

83.5

72.0

142.5

74.0

60»0 70.0

8 20

3 1

0

2 4

8 20

500 500

48.0

N.M.

9.3

21.5

2.67

83.0

73.0

141.5

73.5

f.0.0 70.0

10 20

3 8

2 3

10 20

50 0 50 0

48.0

N.M.

7.7

2 1.5

2.68
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
TELEX DIR OE

M00EL:33D T0NE:CCW TUBING:25MM BATTERY:S76

252

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO. RANDOM NOISE

INPUT LEVEL» DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN OB

HARMONIC DIST

aiNPUT LEVEL OB

500 HZ X

700 HZ X

900 HZ X

MAX DIST X

FREO OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

6 5 DB INPUT

BATTERY VOLTAGE

TE-271 TE-272 TE-273

3331 3526 3591

APR 11, 1975

59 .5 55.5 58. 0

79 .5

125.5

85.0

125.5

79.5

125.5

59. 5 (FULL I 60.0 70.0

20 21

3 7

2 ^ 20 21

500 500

47.5

N. M.

2.1

2.2

1 .56

55.5(FULL

)

63.5 73.5

6 17

4 12

2 4

6 20

500 625

46. 0

N.M.

2. 1 2.2

1 .56

5B.C(FULL)

60.0 70.0

20 32

4 1 1 3 5

20 32

50 0 50 0

48.0

N.M.

2. 1 2.2

1 .56
FREOUFNrv IN HFRT7

FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
TELEX OB

mooel:70 tone:max(cw) p:max(cw) receiver:a8 battery:ioi5

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPOt RANDCM NOISE

INPUT LEVEL. DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC CIST

aiNPUT LEVEL DB

500 HZ %

700 HZ %

9C0 HZ %

MAX DIST %

FREQ OF MAX DI

S

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NC INPUT

65 DB INPUT

BATTERY VOLTAGE

TE-274 TE-275 TE-276

1230 1282 lr335

MAR 28, 1975

65.0

79.5

133 .0

67,0

74. 0

133.0

64. C 75.0

133.0

61 .5

6 CO 70.0

3 7

1 4

3 6

3 7

90 0 500

39.5

N.M.

5.3

1 1 .3

1 .55

59.5

60.0 70.0

5 6

4 4

b 6

6 9

1000 ICOO

44, 5

N.M.

4.9

11.0

1.55

60 . C 60.0 70.

C

2 4

1 2

2 3

4 5

1020 1020

38.5

N.M.

5.0

10.8

1 .55
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
TELEX HP OE

>^0DEL:331H tone:ccw TUBING:25MM BATTERY:S13

257

CODE

SERIAL #

DATE

TE-277

2062

TE-278 TE-279

238C 2363

JUNE 5, 1975

MEASUREMENTS ^ITH

FULL VCL CONTROL * KHZ GAIN DB 7.0

MPG, RANDOM NOISE

INPUT LEVEL* DB 85.0

OUTPUT LEVEL CB 119.0

7.0

85. 0 120.0

6. C 86.5

119.0

MEASUREMENTS (*ITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB -4,5

S/N RATIO DB

2KHZ SIGNAL >38.C

S/HUM RATIO DB

2KHZ SIGNAL N.M.

BATTERY DRAIN, MA

NO INPUT l.O

65 DB INPUT 1.0

BATTERY VOLTAGE 1.54

-4.0

>37.5

N.M.

1.0

1 . 1 1 . 55

-5.5

>39. 0 N.M.

1 .c

1 .0

1 . 55

GAIN REDUCED 5DB AT 1 . 5KHZ .

*Maxiinum setting possible without feedback.
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
TELEX OE

MODEL :334 TONEICCW PWR:CW TUBING: 20MM BATTERY :S76

CODE

SERIAL #

DATE

MEASUREMENTS IKITH

FULL VCL CONTROL

IKHZ GAIN OB

MPO, RANDCM NOISE

INPUT LEVEL* 08

CUTPLT LEVEL DB

MEASUREMENTS Vi I TH

REDUCED VOLUME

CCNTfiCL SETTING

IKHZ GAIN DB

HARMONIC CIST

£INPLT LEVEL OB

500 hZ X 700 HZ %

900 HZ %

MAX DIST %

FREG OF MAX DIS

S/N RATIO 06

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NC INPUT

65 OS INPUT

BATTERY VOLTAGE

TE-28C TE-281 TE-282

359C 3638 3653

MAR 14, 1975

53 . 0

71 .5

111-5

51 . 0

72.

C

1C9.0

50 . 5

72.0

109.5

4-3 . C 60.0 70.0

3 8

1 5

1 6

5 8

141C 960

41 .C

N. M .

2 . 2

2 • 2

1 .55

42.0

60.0 70,0

3 6

1 7

1 7

4 9

1440 960

41.5

N.M .

2.2

2.2

1 . 55

59.5

60. C 70.0

5 12

3 9

2 7

6 12

1470 1470

44.5

N.M.

2.2

2.2

1 . 55
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
TELEX OE

mooel:33a rd tone:2 o'Cuock pwr:ccw tubing:20mm battery;s76

261

CODE

serial » DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO. RANDCM NOISE

INPUT LEVEL. DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VCLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC OIST

aiNPUT LEVEL DB

500 HZ X

700 HZ X

900 HZ X

MAX OIST X

FREC OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 OB INPUT

BATTERY VOLTAGE

TE-283 TE-284 TE-285

2577 34 16 3608

MAR 24. 1975

55.5

79.0

125.0

60.5

80. 0

127.0

59.5

82.0

127.5

61.0 71.0

2 0

1 0

1 0

4 15

1790 1790

45.0

N. M.

2.9

3*3

1 .55

58*5

60 .C 70 .0

3 4

1 2

1 1 3 4

500 500

46.5

N.M.

2.7

3.5

1.55

59.5(FULL)

eo.o 70.

0

3 3

0 2

0 3

3 5

50 0 59 0

44.5

N.M.

2.5

3.7

1 .54
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
vicoN OE 263

model:oei23 tone:a TUBING:22MM BATTERY:S76

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VOL CONTROL

IKHZ GAIN DB

MPO« RANDCM NOISE

INPUT LEVELt DB

OUTPUT LEVEL CB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

aDINPUT LEVEL DB

SCO HZ %

700 HZ X

900 hZ X

MAX DIST %

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO OB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

VI-ZAA VI-245 VI-246

30577 30629 30652^

JAN 29, 1975

48.0

73.0

118.0

49.5

71 .5

1 19.5

50.5

72.0

1 19.C

45.0

60.0 70.0

3 5

1 1 1 1 4 24

1570 1590

49 .0

N.M.

2.0

2.0

1 .55

46. 0

60.0 70.0

2 4

1 1 1 2

3 31

1600 16C0

47. 5

N.M .

2.0

2.0

1.55

47.0

60.0 70.0

2 4

0 1 0 2

4 34

1280 1280

48.5

N.M.

2.0

2.C

1 .55

I

VICON OB

M0DEL:M8 T0NE:#3 SC in RECEIVER:Q1 batteries: 40l< 2)

265

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO, RANDCM NOISE

INPUT LEVEL* DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VCLUME

CCNTRCL SETTING

IKHZ GAIN DB

HARMONIC CIST

©INPUT LEVEL DB

50C HZ X

7C0 HZ %

9C0 HZ %

MAX DIST Si FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

VI-247 VI-248 VI-249

84903 85003 85011

FEB 6. 1975

61.5

71.5

131.0

62.0

72.0

130.5

60.5

70. 5

131.0

49.0

60. 0 70.0

0 4

3 4

5 5

5 5

900 900

30 . 5

N. M.

4.0 3-9

5.2 4.8

1.36 1.38

50. 5

60.0 70.0

0 3

3 4

3 4

3 4

900 900

28.5

N.M.

4.1 4.4

4.8 5.3

1.38 1.34

50. 5

60.0 7C.0

0 3

3 4

4 4

4 4

90 0 90

C

31.0

N.M.

4.2 3.9

5.5 5.C

1.36 1.38
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
VICON OE

M0DEL:0E124 T0NE:A TUBING:22f4M 8ArTERY:S76

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPG. RANDOM NOISE

INPUT LEVEL* DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CCNTRCL SETTING

IKHZ GAIN DB

HARMONIC DIST

SDINPUT LEVEL DB

SCO HZ %

700 HZ %

90 0 HZ %

MAX DIST %

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

VI-250 VI-251 VI-252

30184 30190 30903

JAN 29, 1975

50.0 51.0 49.

C

71 .C

118.0

70.0

118.5

72.

C

118.5

44.0

60-0 70.0

2 1 1 0

0 1 7 26

1580 1580

49.0

N.M.

1 .8

1.8

1 .53

42.5

60.0 70.0

2 i

1 1 C 0

7 16

1620 1600

46. 5

N.M.

1 .9

1.9

1 . 55

44.5

60.0 70.0

2 1 1 1 0 0 5 12

1560 1560

42.5

N.M.

1.9

1.9

1 .54

V I CO N OE

MODEL:OE-150 TONEINONE TUBING:30MM BATTERY:S13

269

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO, RANDOM NOISE

INPUT LEVEL* DB

OUTPUT LEVEL CB

MEASUREMENTS WITH

REDUCED VCLUME

CONTROL SETTING

ikhz gain db

harmonic DIST

aiNPUT LEVEL DB

500 HZ %

700 HZ X

90 0 HZ %

MAX DIST X

FREQ OF MAX DI S

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NC INPUT

65 DB INPUT

BATTERY VOLTAGE

VI-253 VI-254 VI-255

CZC CZV DBW

JAN 30, 1975

63.0

72.0

127.5

63.5

70". 0

127.0

64.5

69.0

L26.X

56.0

60. C 70.0

6 14

2 4

0 1 6 21

50 0 13 20

45.5

N. M.

• 9

2.0

1 .55

56.5

60.0 70.0-

4 12

1 4

C 1 4 16

500 1280

45.5

N.M.

l.C

1.5

1 . 55

55.0

60.0 70.0

4 1 1 1 4

1 2

4 14

5C0 1280

44.5

N.M.

.9

1.9

1 . 54

vicoN DiR oe

model:oei59 tone:a comp:min(cw) tubing:25mm battery:si3

271

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO, RANDOM NOISE

INPUT LEVEL, DB

OUTPUT LEVEL OB

MEASUREMENTS WITH

RECUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

oDINPUT LEVEL DB

500 hZ X

70 0 HZ X

900 HZ %

MAX DIST %

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

VI-256 VI-257 VI-258

EPS ERS EYW

APR 17, 1975

40,5 47. 0 43.0

78.0

111.0

80 .0

111.5

80.5

112.5

37.5

60.0 70.0

8 6

2 2

0 0

8 1

4

50 0 1686

39.5

N.M.

.7

.7

1 .57

39.5

60 .0 70.0

7 5

2 1 0 0

7 13

500 1700

40.5

N.M.

.8

• 8

1 . 57

38.0

60.0 70.0

7 5

2 2

0 C 7 30

500 1560

38.0

N.M .

• 8

• 8

1 ..57
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ

VICON DIR OE

M0DEL:0E158 TONEINONE TUBING:25MM eATTERY:Sl3

274

CODE

SERIAL * DATE

MEASUREMENTS WITH

FULL VCL CONTRCL

IKHZ GAIN DB

MPO, RANDCM NOISE

INPUT LEVEL. DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC CIST

SINPUT LEVEL DB

500 HZ X

700 HZ %

900 HZ %

MAX DIST %

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

VI-259 VI-260 VI-261

EGU EGW EJK

APR 15, 1975

60 .0

74.5

127.0

58.5

78. 0

1 27.0

56.

C

75.0

126.0

56.0 58.0 54.5

60.0 70.0 60.0 70.0 60. C 70.0

10 9 10 16 7 13

3 2 3 5 3 5

0 0 0 1 0 0

10 19 10 16 7 18

500 1340 500 1375 500 1350

45.0 48.0 44.0

N.M. N.M. N.M.

•9 ,9 • 1.0

1.4 1.5 1.6

1«56 1.56 1.55


277

WIOEX OE

mooel:a2T tone:left sc;cw/rt sc;ccw TUBING:22MM BATTERY:S76

CODE

SERIAL ff DATE

WI-100

95002

WI-XOl

9509O

JAN 31. I 97

5

WI-102

95103

MEASUREMENTS WITH

FULL VOL CONTROL

IKHZ GAIN DB 57.0

MPO* RANDOM NOISE

INPUT LEVELt DB 75.5

OUTPUT LEVEL DB 127,5

61.5

73.5

1 27.5

59.5

73.5

127.0

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN OB

-ARMOMC DIST

ffllNPUT LEVEL DB

SCO HZ X

700 hZ X

9C0 HZ %

MAX OIST X

FREQ OF MAX DI

S

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN* MA

NC INPUT

65 DB INPUT

BATTERY VOLTAGE

57.0 (FULL

)

60.0 70.0

6 13

2

16

50 0

44 . 0

N.M.

2.8

3.6

1 .54

4

1 13

500

58. 0

60. C 70.

0

2 3

1 2

0 0

2 6

500 1950

45.5

N.M.

2.6

3.5

1. 54

58.

C

60.0 70.0

2 2

0 2

1 0

2 3

500 1850

46.5

N.M.

2.6

3.7

1 .54
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
WIOEX

model:77 tone:cw

E 279

TUBING:22MM BATTERY:675

CODE

SERIAL » DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPO* RANDOM NOISE

INPUT LEVEL, DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC CIST

aiNPUT LEVEL DB

50 0 HZ X

700 HZ %

900 HZ X

MAX DIST X

FREG OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

Wi-lC3 WI-T1C4 WI-105

7444 7468 7479

JAN 30, 1975

52.0

73.5

119.5

52.0

73.5

119.0

53.0

73.0

119.5

51.0

6C.0 70.0

7 5

1 1

1 1 7 49

SCO 155C

50.5

N.M.

1.3

1.3

1 .40

50. 0

60.0 70.0

5 4

1 1 1 1 5 28

500 1590

50.5

N.M.

1.2

1.2

1.37

52.0

60.0 70.

0

3 2

1 1 1 0

3 40

500 1520

52.5

N.M.

1.2

1.2

1 .37
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
WIDEX HP OE

model:85 tonf;h,cw TUBING:25MM BATTERY;675

281

CODE

SERIAL

DATE

W I- 1 0 6

50063

WI-107

55 075

MAY 20, 1975

WI-108

52163

MEASUREMENTS WITH

FULL VCL CONTROL * IKHZ GAIN DB

MPO. RANDOM NOISE

INPUT LEVEL* DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

1KH2 GAIN DB

S/N RATIO DB

2KHZ SIGNAL

S/HUM RATIO DB

2KHZ SIGNAL

BATTERY DRAIN. MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

23.0

85.0

12 1.5

18.0

42.0

N.M.

1.5

1.5

1 .37

23. 0

86.5

122.0

18.0

45.5

N.M.

1.5

1 . 5

1 . 37

19.5

91.0

123.0

14.5

42.0

N.M .

1.4

1.4

1 .35

Maximum settling possible without feedback.
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
ZENITH CB 283

MODEL : VOCAL I ZER III TONE:FULL PWR:FULL RECEIVER:Y5 BATTERY:401

CODE

SERIAL iff DATE

MEASUREMENTS WITH

FULL VOL CONTROL

IKHZ GAIN DB

MPO, RANDOM NOISE

INPUT LEVEL» DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

DEDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

aiNPUT LEVEL DB

500 HZ X

700 HZ %

900 HZ X

MAX DIST X

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

ZE-286 ZE-287 ZE-288

30057 30261 3C502

JAN 16, 197 5

63.5

87.0

134.5

65 . C 86.0

135.0

64.5

84.5

134.5

63. 5 (FULL ) 60.5 70.5

1 8

2 12

3 11

8 14

14C0 140 0

47.0

N. M.

2 .7

12.0

1 .32

62.0

60.0 7C.0

3 7

3 6

4 9

4 9

900 900

47.0

N.M.

2.7

13.6

i . 33

62. 0

60.0 70.0

3 5

2 4

3 8

3 8

1410 930

45.5

N.M.

3.2

12.0

1.33

ZENITH SPEC EG

model:biphasic tone:none TUBING:35MM BATTERY:M13

285

CODE

SERIAL » DATE

MEASUREMENTS WITH

FULL VOL CONTROL

IKHZ GAIN ere MPO* RANDOM NOISE

INPUT LEVELt DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

aiNPUT LEVEL DB

500 HZ %

700 HZ %

900 HZ %

MAX DIST X FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NC INPUT

65 DB INPUT

BATTERY VOLTAGE

ZE-289 ZE-290 ZE-29 1 0L7346 0L7412 OL7492

JUN 17, 1975

44.

C

75.0

113.5

45.0

74. 0

112.5

44. C

76. 5

112.5

41 .& 41 . 0 Al .5

60-0 70.0 60.0 70.0 60.0 70.0

6 16 7 1 8 7 15

2 6 2 7 2 6

3 9 3 8 3 7

7 21 7 16 7 18

13CC 1300 500 500 50 0 13C0

42.5 43. 0 42.0

N.M. N.M • N.M.

.8 • 6 .9

.8 • 8 .9

1 .31 1. 31 1 .31

THESE ARE THE DATA FOR THE LEFT SIDE OF A SPECIAL BINAURAL

AID, WHICH HAS A DIFFERENT FREQUENCY RESPONSE FOR EACH SIDE

THE DATA FOR THE RIGHT SIDE FOLLOW.
ZENI TH

CONTINUATION OF BIPHASIC

286

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VOL CONTROL

IKHZ GAIN DB

MPG, RANDOM NOISE

INPUT LEVEL, DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CCNTfiCL SETTING

IKHZ GAIN DB

HARMONIC CIST

©INPUT LEVEL DB

SCO HZ %

70 0 HZ %

900 HZ %

MAX DIST X

PREQ OF MAX DiS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NC INPUT

65 DB INPUT

BATTERY VOLTAGE

ZE289A 7E290A ZE291A

CR7346 OR7412 OR7492

JUN 17, 1975

44.5

71.0

110.5

45. 0

70.0

110.5

44. C

73. 5

109.5

38.5 38,5 36.5

60.0 70.0 60.0 70.0 60.0 70.0

5 15 5 15 6 15

2 6 2 6 2 6

3 8 2 7 3 7

8 18 6 16 6 15

1230 1270 1240 1270 50 0 SCO

43.0 44.5 44.

C

N.M. N.M. N«M.

.9 .9 .9

.9 .9 f .9

1.31 1.31 1.31
FREQUENCY IN HERTZ

ZENITH OE

model:command lOO tone:full pwr:full tubing: 25mm battery:si3

289

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

1KH2 GAIN DB

MPO» RANDCM NOISE

INPUT LEVEL, DB

OUTPUT LEVEL OB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

ffllNPUT LEVEL DB

50 0 HZ X

700 HZ %

90 0 HZ %

MAX DIST %

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

ZE-29 2 ZE-293 ZE-294

D11079 D11085 D11146

JAN 23, 1975

44.0 46.5 47.5

88.0

103 .5

86.0

107.5

86.0

107.0

37.0

60.0 7C.0

6 17

1 4

0 I 6 17

SCO 500

39.5

N. M.

.4

.4

1 .56

40.0

60.0 70.0

4 6

1 1 0 0

4 6

SCO SCO

44.0

N.M.

.8

.8

1.53

39.5

60.0 70.0

3 7

1 1 0 1 3 7

50 0 SCO

43.

C

N.M.

.8

.8

1 .53
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
ZENITH CROS EG

MODELICROS TONEZNONE TUBING:4ZMM BATTERY:M-41

291

CODE

SERIAL #

DATE

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN DB

MPOt RANOGM NOISE

INPUT LEVELi DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VCLUME

CONTRCL SETTING

1KH2 GAIN DB

S/N RATIO DB

2KHZ SIGNAL

S/HUM RATIO DB

2KHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

ZE-295 ZE-296 ZE-297

8814916 8815048 8815970

JUN 10. 1975

31.5

83.0

121.5

30.5

84. 0

1 20.0

29. C

84. 0

121.0

26.

C

51 .5

N.M.

1 .6

1 .6

1 .30

25.5

49.0

N.M.

1.6

1.6

1 .30

22. 0

49. 0

N.M .

1.4

1.4

1 .30

THE GAIN GN ZE-297 WAS REDUCED 7 DD INSTEAD OF 5 DB BECAUSE

OF A DISCONTINUITY IN THE VOLUME CONTROL.

ZENITH HP OE

mqoel:oover c pwr:full tubing: ;?5mm battery: si-3

293

code ZE-298 ZE-299 ZE-3C0

SERIAL it 50853 50856 50869

DATE JUNE 5. 1975

MEASUREMENTS IwITH

FULL VCL CONTROL * IKHZ GAIN DB 7.0 6.5 7.0

MPOt RANDOM NOISE

INPUT LEVEL* DB 86.0 86.0 84.

0

OUTPUT LEVEL DB 121.0 121.0 120.0

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB -3.0 -4.0 -4.5

S/N RATIO DB

2KHZ SIGNAL >38-0 >37.0 >39.5

S/HUM RATIO DB

2KHZ SIGNAL N.M. N.M. N.M.

BATTERY DRAIN, MA

NO INPUT 1.0 1.0 1.0

65 DB INPUT 1.0 1.0 1.0

BATTERY VOLTAGE 1.56 1.56 1.56

GAIN REDUCED 5DB AT 1.5KHZ.

*Maximum setting possible without feedback.
FREQUENCY IN HERTZ
ZENITh OE

MODEL :pacemaker EP II tone,pwr:full TUBING:25MM BATTERY:675

295

CODE

serial #

DATE

ZE-30 1 UW812

2E-30 2

JAN 23, 1975

ZE-303

UW859

MEASUREMENTS WITH

FULL VCL CONTROL

IKHZ GAIN OB 56.5

MPO. RANDOM NOISE

INPUT LEVEL, DB 84,0

OUTPUT LEVEL DB 127.5

53.5

82.0

126.0

53.5

81.0

127.5

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

1KH2 GAIN DB

HARMONIC DIST

ffll.NPUT LEVEL

50 0 HZ

700 HZ

900 HZ

MAX DIST

FREG OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO

IKHZ SIGNAL

BATTERY DRAIN,

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

DB

X

%

%

%

DB

MA

56.5(FULL

)

6 1-0

3

5

15

71.0

5

7

3

1 I 700 1270

45.0

N. M.

1 .2

1 .9

1 .34

53.5(FULL

)

6 1.0 71.0

4 8

2

04

500

43.5

N.M.

.7

2.2

1 .33

12

2

12

700

53. 5( FULL)

61 5

3

4

14

70 0

71.5

9

12

4

12

700

45. 0 N.M .

.7

2. 1

1 .33
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
zenith oir oe

model:royal d tone:ccw pwr:full tobing:25mm battery:s76

CODE

SERIAL ft DATE

MEASUREMENTS rtlTH

FULL VCL CONTROL

IKHZ GAIN DB

MPO, RANDOM NOISE

INPUT LEVEL* DB

OUTPUT LEVEL DB

MEASUREMENTS WITH

REDUCED VOLUME

CONTROL SETTING

IKHZ GAIN DB

HARMONIC DIST

ffllNPUT LEVEL DB

SCO HZ X

70 0 HZ X

900 HZ X

MAX DIST X

FREQ OF MAX DIS

S/N RATIO DB

IKHZ SIGNAL

S/HUM RATIO DB

IKHZ SIGNAL

BATTERY DRAIN, MA

NO INPUT

65 DB INPUT

BATTERY VOLTAGE

ZE-304 ZE-305 ZE-306

C63443 C63458 C63549

APR 15t 1975

55.5

78.0

126.5

57.0

79.0

126.5

51 .0

79.0

125.0

53.5

60.0 70.0

2 5

1 2

2 4

4 20

1059 1163

41.5

N.M.

1.2

1.7

1 .54

53.0

60.0 70.0

4 5

2 2

2 4

6 21

1620 1100

42.0

N.M.

1.0

1.7

1.54

49.5

60.0 70.0

3 3

1 0

2 2

4 25

1170 1155

41.5

N.M.

1.0

1.7

1 .54

aF IN
mH-j- -t-'-t-t-t

1^4

-~J

—PAR."

298

±ttt

irrj

El'r

an -

7 -:.!--'

\ -'[•'-

urrt 1

-

.-5 - :m -

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:

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St?-"-;-- z

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3 4 5 6 7 8 9 1000

- 0

, SEH AL IlCXi"

2 4 FREQUENCY IN HERTZ

FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
FREQUENCY IN HERTZ

FREQUENCY IN HERTZ
300

IV. PERFORMANCE MEASUREMENT DATA FROM THE

BIOCOMMUNICATIONS LABORATORY,

UNIVERSITY OF MARYLAITD

G. Donald Causey

Lucille B. Beck

Jerry L. Punch

Howard C. Schweitzer
301

Equipment Array

Testing of special instriaments for the 1976 Hearing Aid

Program was conducted at the Biocommunications Laboratory,

University of Maryland, utilizing the Knowles Electronics Manikin

for Acoustic Research (KEMAR) . A full description of KEMAR is

provided by Burkhard and Sachs (1975). CROS , BICROS, compression,

directional, and high frequency hearing aids submitted for Contract

Year 1976 were evaluated. A diagram of the equipment utilized for

measurements on KEMAR is shown in Figure 1.

A Bruel and Kj aer hearing-aid test system was utilized in

conjunction with an anechoic chamber having an internal volume of

343 cubic feet (7' x 7' x 7'). The B & K 1022 beat frequency

oscillator generated the signal which was led to a Mcintosh power

amplifier and subsequently to a JBL LEST speaker placed directly

in front of KEMAR (in a 0° azimuth relationship) at a distance of

1 meter from the midpoint of a line between KEMAR' s ears,

A Scully model 280 %" full track tape recorder and a B & K

1405 noise generator were also used in the system for producing

tape-recorded materials and noise, respectively. A B & K %"

condenser microphone, model 4134, was attached to a Zwislocki

coupler on KEMAR' s right side. This microphone was led to a B & K

2606 measuring amplifier, where the sound pressure level from

KEMAR' s ear was monitored. The output of the B & K 2606 measuring

amplifier was delivered to a B & K 2307 graphic level recorder.

In addition, a B & K model 4131 1" condenser microphone, located

either over KEMAR' s head or near his right ear, was connected to

a second B & K 2606 measuring amplifier. This arrangement permitted the monitoring of sound pressure level in the free field

in which KEMAR was placed. A compression, or regulating, circuit

was connected to the coupler microphone to maintain a constant

sound pressure level across frequencies when deemed necessary.

Measurement of Saturation Sound Pressure Level (SSPL) was

obtained with a pink noise stimulus (-3 dB octave). The input

SPL of the pink noise, as monitored one inch above KEMAR' s head,

was increased in 5 dB steps until there was less than a 1 dB

change in output. The first input level where this occurred was

called SSPL. For example:

Input Output

Saturation SPL

60

65

70

75

80

85

110

115

117

120

122

122
302

CM

uo O

CO

1—1

•riO

CO

m

O <

i-l 0)

CNl 4J m c3ou o

00

CM

1-1 Pi

1—1 • 3 H O

in . o c5

COo

CO z o o

CO <u Pi

r-l>

pa »j
Saturation SPL was 122 dB, established at an input level of

80 dB SPL.

Pure tone stimuli in the frequency range from 100 to 10,000

Hz were utilized in obtaining responses of amplitude by frequency. Measurement of the orthotelephonic response (Baranek,

1949, p. 621) was utilized for the specification of frequency

response in each of the different types of special instruments.

The %" condenser microphone attached to the Zwislocki coupler

in KEMAR's ear was made the regulating microphone by activating

the previously mentioned compression circuit. The output of the

oscillator, controlled by the compression circuit to produce

60 dB SPL throughout the frequency range 100 to 10,000 Hz, was

recorded on magnetic tape by a Scully 280 tape recorder. The

microphone in the coupler was subsequently converted to the measuring microphone, and the tape-recorded signal was played

synchronously with the frequency markings on the recording paper

of the graphic level recorder. When the tape-recorded stimuli

were played back using the microphone in the Zwislocki coupler

(previously the regulating microphone) as a measuring microphone,

a flat frequency response was obtained, thereby verifying the

efficacy of the recording technique. The tape-recorded pure tone

stimuli were then utilized for all testing of hearing aids with

KEMAR. The reader will notice that the curves are less smooth

than those obtained with a 2cc coupler, due to the attendant

diffraction and/or open ear canal effects associated with measure

ment on KEMAR.

With the previous discussion of equipment and methods for

measurement of SSPL and frequency response in mind, a description

of procedures used for each of the special categories follows.

The data obtained on each instrument are presented after each

procedural description.

References

Beranek, L. S. Acoustic Measurements . New York: John Wiley

6c Sons , Inc. , 1949.

Burkhard, M, D. and Sachs, R. M. Anthropometric Manikin for

Acoustic Research. J. Acoust . Soc . Amer . , 58: 214-222,

(1975). ~
304

CROS HEARING AIDS

Frequency Response

A non-occluding earmold with cemented tubing, 2 mm in inside

diameter and 4 cm in length, was inserted into KEMAR's right ear. The hearing aid under test was attached to the tubing of KEMAR's

earmold and placed so as to rest on the auricle. Saturation

Sound Pressure Level (SSPL) was determined, and the volume control

was then adjusted to yield an output 12 dB below SSPL with a 60

dB pink noise input. Using the system calibrated as previously

described, a frequency response tracing (60 dB input) of the hearing aid at 0° azimuth was then obtained. Four CROS hearing aids

were tested in this fashion.
305
306
BICROS HEARING AIDS

307

Frequency Response

An occluding earmold with cemented tubing, 2 mm in inside

diameter and 4.6 cm in length, was inserted into KEMAR's right

ear. The hearing aid under test was attached to the tubing of

KEMAR's earmold and placed so as to rest on the auricle. The

volume controls were set to full on, or reduced by the degree necessary to prevent feedback, as monitored audibly, and with the aid

of an oscilloscope. Absolute output values were reflective of this

gain control adjustment in many cases. Saturation Sound Pressure

Level (SSPL) was determined, and the volume control was then adjusted to yield an output 12 dB below SSPL with a 60 dB pink noise

input. Using the system calibrated as previously described, a frequency response tracing (60 dB input) of the aid at 0° azimuth was

then obtained. Four BICROS hearing aids were examined in this

fashion.
308

ri 1

SSF Otar Lon > Ga± 1 at 1 0— —Tffl- H

9^ ==r- —

I

- M

—

t

M

a«r

1

'

1 ^

500 1000 2000 my' seee fw
309
COMPRESSION HEARING AIDS

310

Frequency Response

An occluding earmold with cemented tubing, 2 mm in inside

diameter and 4.6 cm in length, was inserted into KEMAR' s right ear. The hearing aid under test was attached to the tubing of KEMAR'

s

earmold and placed so as to rest on the auricle. The volume controls were set to full on, or reduced by the degree necessary to

prevent feedback, as monitored audibly, and with the aid of an oscilloscope. Absolute output values were reflective of this gain

control adjustment in many cases. Saturation Sound Pressure Level

(SSPL) was determined, and the volume control was then adjusted to

yield an output 12 dB below SSPL with a 60 dB pink noise input.

Using the system calibrated as previously described, three frequency

response tracings at input levels of 60, 70, and 80 dB input were

obtained at 0° azimuth for each aid. Seventeen compression hearing

aids were examined in this fashion.

Attack-Release Times

A 1000 Hz signal was generated by the B & K 1022 oscillator,

and gated by Grason-Stadler 1200 modular equipment to produce a square envelope signal varying repetitively at 2 second intervals

from 55 to 80 dB SPL, as monitored free-field at KEMAR' s open right

ear. Each change in amplitude was instantaneous and occurred at

zero crossing on the waveform. The output of the gating network

was amplified and led to the front loudspeaker. Continuous monitoring of the input levels, while the aid was in place, was made

possible by use of the field microphone (B & K 4131) as reference,

positioned one inch from the entrance to KEMAR' s right ear. Eleven over-the-ear instruments were evaluated using an oc- cluding earmold with cemented tubing (described previously) , while

six body-worn instruments were tested using an occluding earmold

with snap ring. For measurements on the body-worn instruments, the

instrvmient itself was mounted centrally on KEMAR' s torso in a body

harness, the top of which was situated 13 inches below a plane

projected anteriorly from KEMAR' s tragus. A total of 17 compression

aids were evaluated.

The gain controls of the aids were set to full-on, or reduced

by an amount necessary to prevent audible feedback. The oscilloscope

was also used as an ancillary aid in feedback monitoring.

On instruments having external controls, only one combination

of settings was employed in evaluating each of the aids. In all

applicable cases, this combination consisted of settings compatible

with maximum compression, shortest release time, and tone control

setting recommended by the manufacturer for routine testing.
311

The aided output signal was delivered to the B & K 2606

measuring amplifier and subsequently led to a digital event re- corder (B 6c K 7502), shown in Figure 1. The latter component

allowed precision recording and playback of the output waveforms

over variable time periods by its incorporation of a wide range

of input /output sampling rates. The output of the event recorder

was led to an oscilloscope, and Polaroid photographs were made of

each separate attack and release display. Attack and release

times were calculated directly from these photographs, using voltage ratios corresponding to + 2 dB of steady state values. Accordingly, attack time is here defined as the time interval

between the moment when the input SPL is increased instantaneously

by 25 dB and the moment when the output SPL from the hearing aid

stabilizes, within 2 dB, at the elevated steady state level. The

release time is defined as the time interval between the moment

when the output SPL from the hearing aid stablizes, within 2 dB,

at the lowered steady state level.

The loudspeaker response to the electrical waveform revealed

restoration of the input waveform within approximately 5 msec for

both directions of amplitude shift. Thus, in Table I a value of

5 msec indicates a response as short as that of the loudspeaker

source itself.

Input -Output Graphs

The pink noise output of the B & K 1405 Noise Generator was

amplified and delivered to the front loudspeaker. Continuous input

monitoring was made possible while the hearing aid was in place

by employing a 1" condenser microphone (B & K 4131) as reference,

positioned one inch from the entrance to KEMAR's right ear.

In evaluating over-the-ear instruments, the occluding earmold

with cemented tubing was used, while the occluding mold with snap

ring was utilized in evaluating body-worn instruments (i.e.

,

HC Electronics Phonic Ear). In the latter instance, the instrument

itself was mounted centrally on the torso in a body harness, the

top of which was situated 13 inches below a plane projected anteriorly from KEMAR's tragus.

Seventeen compression hearing aids were evaluated, eleven of

which were over-the-ear types, and six of which were body-worn

instruments. The gain controls of the aids were set to full-on,

or reduced by the degree necessary to prevent feedback, as monitored

audibly and with the aid of an oscilloscope. Absolute output

levels, therefore, were reflective of this gain control adjustment

in many cases. Input levels ranged from 50 through 80 dB SPL, in

steps of 5 dB.

On instruments having external controls, only one combination

of settings was employed in the data collection. In every applicable

instance, this combination consisted of settings compatible with

maximum compression, shortest release time, and tone control setting recommended by the manufacturer for routine testing.

200 500 1000 2000 5000 101

k —f Emcz

Gai 1 at 1 -m

^—

1

-fl

n

n

200 500 1000 2000 5000 '^^^tM
314

•J

T3

5000

i. -wSo 500 1000 2000 5000


317
TABLE I. Attack and release times, measured as time (msec)

required to achieve steady state condition (+ 2 dB) in

corrpression hearing aids.

Hearing Aid Attack Time Release Time

Fidelity F-37 5 40

HC Electrcnics

Phonic Ear LN 10 240

LP 10 520

LW 5 520

SEN 15 920

SEP 5 480

SEW 5 240

Norelco 8274 5 60

Nbrelco 8275 5 55

Oticon 565 SZ-UX) 5 45

Qualitone CSD 10 80

Radioear 1030 B 10 30

Rexton 4112 5 20

Siemens 22 AVC 25 200

Siemens 32 D 5 5

Vicon 159 5 10

Zenith Caimand 100 20 300
319
120

115

110

^ 105

PQ

S 100 H

O

95

90

85 -

I i Fidelity F-37

Norelco 827A

Norelco 8275

Oticon 565 SZ-LDC

Qualitone CSD

Radioear 1030 B

O O

1 1 1

50 55 60 65 70

INPUT IN dB SPL

75 80

Figure 2b. Input-output graph for compression hearing aids
321

60 65 70

INPUT IN dB SPL

Figure 2c. Input-output graph for compression hearing aids
322

HIGH FREQUENCY HEARING AIDS

Frequency Response

A non-occluding earmold with cemented tubing, 2 mm in inside

diameter and 4 cm in length, was inserted into KEMAR's right ear. The hearing aid under test was attached to the tubing of KEMAR's

earmold and placed so as to rest on the auricle. The volume control

of the hearing aid was adjusted to a setting just below detectable

acoustic feedback. Using a pink noise stimulus the volume control

then was reduced five decibels from the previously established setting of just below detectable acoustic feedback to ensure the

absence of incipient feedback. Using the system calibrated as previously described, a frequency response tracing (60 dB input)

of the hearing aid at 0° azimuth was then obtained. Fourteen high

frequency hearing aids were examined in this fashion.





328

DIRECTIONAL HEARING AIDS

Frequency Response

An occluding earmold with cemented tubing, 2 mm in inside

diameter and 4.6 cm in length, was inserted into KEMAR's right

ear. The hearing aid xinder test was attached to the tubing of

KEMAR's earmold and placed so as to rest on the auricle. The

volume controls were set to full on, or reduced by the degree

necessary to prevent feedback, as monitored audibly, and with the

aid of an oscilloscope. Absolute output values were reflective

of this gain control adjustment in many cases. Saturation Sound

Pressure Level (SSPL) was determined and the volume control was

then adjusted to yield an output 12 dB below SSPL with a 60 dB

pink noise input. Using the system calibrated as previously

described, frequency response tracings (60 dB input) of the hearing

aid at 0° and 180° azimuth were obtained.

Previous investigation of directional aids indicated that no

additional information was obtained with a 90° and 270° azimuth

curve because the 90° curve essentially followed the 0° curve and

the 270° curve closely followed the 180° curve.

Front to Back Ratio

The Bruel & Kjaer 1405 noise generator was utilized to produce

white noise which was delivered to each of two matched speakers

(front and back) , located at 0° and 180° azimuth from the test point

in the anechoic chamber. Calibration of the white noise stimulus

through the speakers was accomplished with KEMAR removed from the

chamber. The test point was identified as the midpoint of an imaginary

line perpendicular to the speaker cones, one meter from each of the

two speakers. A monitor microphone (B & K 4131) permitted the adjustment of two attenuator networks for the production of 60 dB SPL

from each speaker in turn at the test point. The monitor microphone

was then removed from the test point, and KEMAR was returned to the

chamber in such fashion that the test point was located midway between

his ears

.

The hearing aid was connected to an occluding earmold with snap

ring for the Front to Back Ratio measurement. During preliminary

evaluation, the investigators noted that slight variations in placement of the aid on KEMAR could markedly affect the results. All

aids were placed on KEMAR so that they rested behind the pinna in

the same way that they would be worn by a human listener. For all

aids it was determined that either 20 mm or 13 mm tubing length would

permit an appropriate fit.

White noise was presented through the front speaker at the

previously-established level of 60 dB SPL, and the output of the

hearing aid was noted. This proceudre was repeated using the back
speaker. The Front to Back Ratio was computed by subtracting the

output SPL of the hearing aid with signal from the back speaker

from output SPL of the hearing aid with signal from the front

speaker. Nineteen directional hearing aids were examined in this

fashion.


Gain a i=Ig

11^

332

Front to Back I.atio :

2

^3 ;5

4

i 0-1 200 500 1000 2000 100OO

SGPL: 11 8 d fr Norc

Gain a t—ii^ Front

2

g

11 6

500 1000 2000 5000

5000



SPECIAL TEST DATA ON HEARING AIDS SELECTED FOR

mNTRACT YEAR 1976

Lucille B. Beck

Eleanor S. Wintercorn
337

)

AUDIOLOGIST-ADJUSTABLE TONE CONTROL SETTINGS

In the following section, frequency responses are included

for the hearing aids on contract which have audiologist-adjustable

tone control settings. The purpose of this section is to depict

the alteration of frequency response when the tone control setting

of the aid is manipulated. All curves were obtained utilizing the

2cc coupler at the 12 dB down volume control setting according to

NBS procedures (Hearing-Aid Performance Measurement Data and HearingAid Selection Procedures, 1975).

In the legend beneath each aid, the manner of adjusting tone

controls for the obtained frequency responses is described. The

term internal is used when the tone control adjustment is located

inside the battery compartment. The term external is used to indicate tone control adjustments which are located on the outside of

the case. The legend further specifies whether the tone control

is a switch or screwdriver-operated control. In the designation

of tone control for each hearing aid, the terminology used by the

manufacturer was employed for this description of tone control

settings

.

VOLUME CONTROL TAPER

Frequency response as a function of volume control taper

was measured for each of the Contract Year 1976 hearing aids.

The selected volume control settings were obtained by manipulating

the volume control wheel to indicate 100% (full on), 75%, 50%,

and 25%, rotation.

Frequency response measurements were made utilizing the

2cc coupler and a Bruel & Kj aer hearing aid test system. The

input sound pressure level was 60 dB. The gain in dB SPL at

1000 Hz for each voltime control setting is provided on the frequency response of each aid.
338 I

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372

CONTRACT YEAR 1976

AUDIOTONE

A-20 P5

Over-the-Ear

High Pass

SPECIFICATIONS

*Gain

*SSPL

Receiver

12 dB

125 dB

Internal

SETTINGS AND ADJUSTMENTS

External

1.

2.

3.

On-off switch incorporated with battery compartment

Telephone switch

Volume control

Internal

None

BATTERY DATA

Type 675

Voltage 1.4

Two week supply with 16 hours of hearing aid use per day: 3 batteries

*The indicated data represent the mean values on the physical measurements made on samples of this hearing aid model by the National Bureau

of Standards and the Biocommunications Laboratory, University of Maryland

according to their cited procedures. Gain and SSPL output are specified

with a tolerance of plus or minus 2 dB.

NOTE: Gain was measured with open earmold using Zwislocki coupler in

KEMAR. This procedure necessitated the use of reduced volume control

setting.

-'^The reported gain represents the mean gain for three samples of the

model, computed using the values at the six midpoints of the bands of

frequencies between 1000 and 2000 Hz.
373

CONTRA.CT YEAR 1976

AUDIOTONE

A-24

Over-the-Ear

BICROS

SPECIFICATIONS

*Gain dB

*SSPL 118 dB

Receiver Internal

SETTINGS AND ADJUSTMENTS

External: 1. On-off switch on volume control side

2. Microphone-telephone switch on opposite side

3. Volume control

BATTERY DATA

Type M41

Voltage 1.4

Two week supply with 16 hours of hearing aid use per day: ^ batteries

(Requires one battery in side with volume control.)

*The indicated data represent the mean values on the physical measurements made on samples of this hearing aid model by the National Bureau

of Standards and the Bio communications Laboratory, University of Maryland,

according to their cited procedures. Gain and SSPL output are specified

with a tolerance of plus or minus 2 dB.

*The reported gain represents the mean gain for three samples of the model

measured at 1000 Hz.
CONTRACT YEAR 1976

374

AUDIOTONE

A-24D

Over-the-Ear

Moderate Power

SPECIFICATIONS

*Gain 45 dB

*SSPL 119 dB

Receiver Internal

SETTINGS AND ADJUSTMENTS

External: 1. On-off switch incorporated in battery compartment

2. Volume control

3. Two position tone control

R2 - normal response

R4 - high frequency emphasis

BATTERY DATA

Type M41

Voltage 1.4

Two week supply with 16 hours of hearing aid use per day: 4 batteries

*The indicated data represent the mean values on the physical measurements made on samples of this hearing aid model by the National Bureau

of Standards and the Biocommunications Laboratory, University of Maryland,

according to their cited procedures. Gain and SSPL output are specified

with a tolerance of plus or minus 2 dB.

NOTE: Underlined items denote those Specifications and/or Settings and

Adjustments used in the physical measurement procedure to obtain the

reported statements of gain, SSPL, and frequency response.

*The reported gain represents the mean gain for three samples of the

model, computed using the values at the nine midpoints of the bands of

frequencies between 500 and 2000 Hz.
375

CONTRACT YEAR 1976

AUDIVOX

37

Eyeglass

' Mild Power

SPECIFICATIONS

*Gain 41 dB

*SSPL 113 dB

Receiver Internal

SETTINGS AND ADJUSTMENTS

External: 1. On-off switch incorporated in volxime control

BATTERY DATA

Type 675

Voltage 1.4

Two week supply with 16 hours of hearing aid use per day: 2 batteries

*The indicated data represent the mean values on the physical measurements made on samples of this hearing aid model by the National Bureau

of Standards and the Biocommunications Laboratory, University of Maryland,

according to their cited procedures. Gain and SSPL output are specified

with a tolerance of plus or minus 2 dB.

*The reported gain represents the mean gain for three samples of the

model, computed using the values at the nine midpoints of the bands of

frequencies between 500 and 2000 Hz.
376

CONTRACT YEAR 1976

AUDIVOX

115X

Over-the-Ear

Strong Power

SPECIFICATIONS

*Gain 59 dB

*SSPL 130 dB

Receiver F-2

Cords 3" cord - No. 1051-92

11" cord (for opposite ear fitting)

SETTINGS AND ADJUSTMENTS

External: 1. On-off switch incorporated in volume control

2. Microphone-Telephone switch

BATTERY DATA

Type 675

Voltage 1.4

Two week supply with 16 hours of hearing aid use per day: 6 batteries

*The indicated data represent the mean values on the physical measurements made on samples of this hearing aid model by the National Bureau

of Standards and the Biocommunications Laboratory, University of Maryland,

according to their cited procedures. Gain and SSPL output are specified

with a tolerance of plus or minus 2 dB.

*The reported gain represents the mean gain for three samples of the

model, computed using the values at the nine midpoints of the bands of

frequencies between 500 and 2000 Hz.
CONTRACT YEAR 1976

377

DAHLBERG

HF 1250

Eyeglass

Strong Power

SPECIFICATIONS

*Gain 58 dB

*SSPL 129 dB

Receiver Internal

SETTINGS AND ADJUSTMENTS

External: 1. On-off switch incorporated in volume control

2. Three position switch

M - Microphone

B - Both

T - Telephone

**3. Continuously variable compression control (C) (located

on inside of temple) between white markings corres- ponding to 2 o'clock and 10 o'clock positions.

2 o'clock - minimum compression

10 o'clock - maximum compression

**4. Continuously variable low frequency response control

(L) (located on inside of temple) between white

markings corresponding to 2 o'clock and 10 o'clock

positions

2 o'clock - normal response

10 o'clock - maximum low frequency cut

**CAUTION: If position indicator is rotated beyond these two

extremes, the control must be recalibrated by turning two

complete turns counter to the arrow, stopping at 2 o'clock.

BATTERY DATA

Type 675

Voltage 1.4

Two week supply with 16 hours of hearing aid use per day: 6 batteries

*The indicated data represent the mean values on the physical measurements made on samples of this hearing aid model by the National Bureau

of Standards and the Biocommunications Laboratory, University of Maryland,

according to their cited procedures. Gain and SSPL output are specified

with a tolerance of plus or minus 2 dB.

NOTE: Underlined items denote those Specifications and/or Settings and

Adjustments used in the physical measurement procedure to obtain the

reported statements of gain, SSPL, and frequency response.

=^he reported gain represents the mean gain for three samples of the

model, computed using the values at the nine midpoints of the bands of

frequencies between 500 and 2000 Hz.
CONTRACT YEAR 1976

DAHLBERG

HG 1250

Eyeglass

BICROS

SPECIFICATIONS

*Gain 56 dB

*SSPL 128 dB

Receiver Internal

SETTINGS AND ADJUSTMENTS

External: 1. On-off switch incorporated in volume control

2. Three position microphone-telephone switch

M - Microphone

B - Both

T - Telephone

**3. Continuously variable compression control (C) (located

on inside of temple) between white markings corres- ponding to 2 o'clock and 10 o'clock positions.

2 o'clock - minimtim compression

10 o'clock - maximum compression

**4. Continuously variable low frequency response control

(L) (located on inside of temple) between white

markings corresponding to 2 o'clock and 10 o'clock

positions

2 o'clock - normal response

10 o'clock - maximum low frequency cut

**CAUTI0N: If position indicator is rotated beyond these

two extremes, the control must be recalibrated by turning

two complete turns counter to the arrow, stopping at

2 o'clock.

BATTERY DATA

Type 675

Voltage 1.4

Two week supply with 16 hours of hearing aid use per day: 8 batteries

Note: Battery in each temple required; however, battery life in

temple with microphone only is estimated at 500 hours.

*The indicated data represent the mean values on the physical measurements made on samples of this hearing aid model by the National Bureau

of Standards and the Biocommunications Laboratory, University of Maryland,

according to their cited procedures. Gain and SSPL output are specified

with a tolerance of plus or minus 2 dB.

NOTE: Underlined items denote those Specifications and/or Settings and

Adjustments used in the physical measurement procedure to obtain the

reported statements of gain, SSPL, and frequency response.

*The reported gain represents the mean gain for three samples of the

model, computed using the values at the nine midpoints of the bands of

frequencies between 500 and 2000 Hz,
379

CONTRACT YEAR 1976

DAHLBERG

JC 1254

Eyeglass

CROS

SPECIFICATIONS

*Gain 46 dB

*SSPL 118 dB

Receiver Internal

SETTINGS AND ADJUSTMENTS

External: 1. On-off switch Incorporated in volume control

2. Three position microphone-telephone switch

M - Microphone

B - Both

T - Telephone

**3. Continuously variable compression control (C) (located

on underside of temple housing microphone) between

white markings corresponding to 2 o'clock and 10 o'clock

positions

2 o'clock - minimum compression

10 o'clock - maximum compression

**4. Continuously variable low frequency response control

(L) (located on inside of temple) between white

markings corresponding to 2 o'clock and 10 o'clock

positions

2 o'clock - normal response

10 o'clock - maximum low frequency cut

**CAUTION: If position indicator is rotated beyond these

two extremes, the control must be recalibrated by turning

two complete turns counter to the arrow, stopping at

2 o'clock.

BATTERY DATA

Type Ml

3

Voltage 1.4

Two week supply with 16 hours of hearing aid use per day: 4 batteries

*The indicated data represent the mean values on the physical measurements made on samples of this hearing aid model by the National Bureau

of Standards and the Biocommunications Laboratory, University of Maryland,

according to their cited procedures. Gain and SSPL output are specified

with a tolerance of plus or minus 2 dB.

NOTE: Underlined items denote those Specifications and/or Settings and

Adj ustments used in the physical measurement procedure to obtain the

reported statements of gain, SSPL, and frequency response.

*The reported gain represents the mean gain for three samples of the model

measured at 2000 Hz.
CONTRACT YEAR 1976

FIDELITY

Eyeglass

Bone Conduction

SPECIFICATIONS

Clinical evaluations indicate that this instrument is most successful

when used for mild to moderate conductive hearing losses.

*SETTINGS AND ADJUSTMENTS

External: 1. On-off switch incorporated in battery compartment

2. Volume control

3. Microphone- telephone switch

BATTERY DATA

Type 675

Voltage 1.4

Two week supply with 16 hours of hearing aid use per day: 2 batteries

*This information was extracted from manufacturer's literature.
381

CONTRACT YEAR 1976

LEHR

STAR 6 AVCD

Over-the-Ear

Directional

SPECIFICATIONS

*Gain 42 dB ' *SSPL 120 dB

Receiver Internal

SETTINGS AND ADJUSTMENTS

External: 1. Three position control

White Dot - Off

T - Telephone

M - Microphone

2. Volume control

Internal: 1. Continuously AVC (marked A in battery compartment)

Full counterclockwise setting - minimum AVC

Full clockwise setting - maximum AVC (-8 dB)

,2. Continuously variable peak clipping (marked P in the

battery compartment)

Full clockwise setting - minimum peak clipping

Full counterclockwise setting - maximum peak clipping

(-13 dB)

BATTERY DATA

Type 675

Voltage 1.4

Two week supply with 16 hours of hearing aid use per day: 2 batteries

*The indicated data represent the mean values on the physical measurements made on samples of this hearing aid model by the National Bureau

of Standards and the Biocommunications Laboratory, University of Maryland,

according to their cited procedures. Gain and SSPL output are specified

with a tolerance of plus or minus 2 dB.

NOTE: Underlined items denote those Specifications and/or Settings and

Adjustments used in the physical measurement procedure to obtain the

reported statements of gain, SSPL, and frequency response.

*The reported gain represents the mean gain for three samples of the

model, computed using the values at the nine midpoints of the bands of

frequencies between 500 and 2000 Hz,
CONTRACT YEAR 1976

LEHR

STAR 6F

Over-the-Ear

Moderate Power

SPECIFICATIONS

*GHi.n 55 dB

*:-S>'L 127 dB

lieceiver Internal

SETTINGS AND ADJUSTMENTS

External: . 1. Three position control white Dot - Off

T- Telephone

M- Microphone

2. Volume control

Internal: P. C. (Compression) in battery compartment.

Counter clockwise for full compression.

Clockwise - minimum compression

BATTERY DATA

Type 675

Voltage 1.4

T\<ro week supply with 16 hours of hearing aid use pe" day: 3 batteries

*The indicated data represent the mean values on the physical measurements

made on samples of this hearing aid model by the National Bureau of

Standards and the Biocommunications Laboratory, University of Maryland,

according to their cited procedures. Gain and SSPL output are specified

with a tolerance of plus or minus 2 dB.

NOTE: Underlined items denote those Specifications and/or Settings and

Adjustments used in the physical measurement procedure to obtain the

reported statements of gain, SSPL, and frequency response.

*Th.e reported gain represents the mean gain for three samples of the model,

computed using the values at the nine midpoints of the bands of frequencies

between 500 and 2000 Hz.
CONTRACT YEAR 1976

383

LEHR

Optica 6

Eyeglass

Moderate Power

SPECIFICATIONS

*Gain 47 dB

*SSPL 121 dB

Receiver Internal

SETTINGS AND ADJUSTMENTS

External: 1. On-off switch incorporated in battery compartment

2. Volume control

3. Three position microphone-telephone switch

M - Microphone

T - Telephone

MT - Both

4. Variable tone control located on underside of temple

piece

L - Normal

H - High frequency emphasis

Internal: None

BATTERY DATA

Type 675

Voltage 1.4

Two week supply with 16 hours of hearing aid use per day: 3 batteries

*The indicated data represent the mean values on the physical measurements made on samples of this hearing aid model by the National Bureau

of Standards and the Bio coiranunicat ions Laboratory, University of Maryland,

according to their cited procedures. Gain and SSPL output are specified

with a tolerance of plus or minus 2 dB.

NOTE: Underlined items denote those Specifications and/or Settings and

Adjustments used in the physical measurement procedure to obtain the

reported statements of gain, SSPL, and frequency response.

'<Che reported gain represents the mean gain for three samples of the

model, computed using the values at the nine midpoints of the bands of

frequencies between 500 and 2000 Hz.
384

CONTRACT YEAR 1976

NORELCO

HP 8252

Over-the-Ear

Mild Power

SPECIFICATIONS

*Gain 37 dB

*SSPL 111 dB : Receiver Internal

SETTINGS AND ADJUSTMENTS

External: 1. Three position switch

0 - Off

M - Microphone

T - Telephone

2. Volxime control

BATTERY DATA

Type 675

Voltage 1.4

Two week supply with 16 hours of hearing aid use per day: 2 batteries

*The indicated data represent the mean values on the physical measurements made on samples of this hearing aid model by the National Bureau

of Standards and the Biocommunications Laboratory, University of Maryland,

according to their cited procedures. Gain and SSPL output are specified

with a tolerance of plus or minus 2 dB.

*The reported gain represents the mean gain for three samples of the

model, computed using the values at the nine midpoints of the bands of

frequencies between 500 and 2000 Hz.
385

CONTRACT YEAR 19 76

NORELCO

HP 8269

Over-the-Ear

High Pass

SPECIFICATIONS

*Gain 31 dB

*SSPL 120 dB

Receiver Internal

SETTINGS AND ADJUSTMENTS

External

2.

3.

4.

Three position switch:

M - Microphone

T - Telephone

0 - Off

Voliime control

Three position PC control:

1 - Minimum sound output

3 - Medium sound output

5 - ^Maximum sound output

Continuously adjustable gain control:

Full counterclockwise setting - minimum gain

Full clockwise setting - maximum gain.

BATTERY DATA

Type 675

Voltage 1.4

Two week supply with 16 hours of hearing aid use per day: 3 batteries

*The indicated data represent the mean values on the physical measurements made on samples of this hearing aid model by the National Bureau

of Standards and the Bio communications Laboratory, University of Maryland,

according to their cited procedures. Gain and SSPL output are specified

with a tolerance of plus or minus 2 dB.

NOTE: Underlined items denote those Specifications and/or Settings and

Adjustments used in the physical measurement procedure to obtain the

reported statements of gain, SSPL, and frequency response. Gain was measured with open earmold using Zwislocki coupler in KEMAR. This

procedure necessitated the use of reduced volume control setting.

*The reported gain represents the mean gain for three samples of the

model, computed using the values at the six midpoints of the bands of

frequencies bet^'/een 1000 and 2000 Hz.
CONTRACT YEAR 1976

NORELCO

HP 8274

Over-the-Ear

Compression

SPECIFICATIONS

*Gain 45 dB

*SSPL 117 dB

Receiver Internal

SETTINGS AM) ADJUSTMENTS

External: 1. Three position control

0 - Off

T - Telephone

M - Microphone

2. Volume Control

3. Tone control

N - Normal

H - Low frequency cut

4. Limitation adjustment with three positions

5 (maximum output) . 3 (approximate 5 dB reduction)

.

1 (approximate 10 dB reduction)

5. Compression adjustment

2 - minimal compression

4 - moderate compression

7 - maximum compression

6. Recovery time adjustment

F - short recovery time

5 - long recovery time

Internal: None

BATTERY DATA

Type 675

Voltage 1.4

Two week supply with 16 hours of hearing aid use per day: 3 batteries

*The indicated data represent the mean values on the physical

measurements made on samples of this hearing aid model by the Biocommunications Laboratory, University of Maryland, according to their

cited procedures. Gain and SSPL output are specified with a tolerance

of plus or minus 2 dB.

NOTE: Underlined items denote those Specifications and/or Settings and

Adj ustments used in the physical measurement procedure to obtain the

reported statements of gain, SSPL, and frequency response.

^he reported gain represents the mean gain for three samples of the

model, computed using the values at the nine midpoints of the bands of

frequencies between 500 and 2000 Hz.
387

CONTRACT YEAR 1976

NORELCO

8288

Over- the-Ear

Directional

SPECIFICATIONS

*Gain 43 dB

*SSPL 115 dB

Receiver Internal

SETTINGS AND ADJUSTMENTS

External: 1. Three position switch

0 - Off

M - Microphone

T - Telephone

2. Volume control

3. Tone control - on side of chassis

N - Normal

H - High frequency emphasis

4. Continuously adjustable gain control on side of

chassis

Full counterclockwise setting - minimxm gain

Full clockwise setting - maximum gain

BATTERY DATA

Type 675

Voltage 1.4

Two week supply with 16 hours of hearing aid use per day: 2 batteries

*The indicated data represent the mean values on the physical measurements made on samples of this hearing aid model by the National Bureau

of Standards and the Biocoramunications Laboratory, University of Maryland,

according to their cited procedures. Gain and SSPL output are specified

with a tolerance of plus or minus 2 dB.

NOTE: Underlined items denote those Specifications and/or Settings and

Adj ustments used in the physical measurement procedure to obtain the

reported statements of gain, SSPL, and frequency response.

*The reported gain represents the mean gain for three samples of the

model, computed using the values at the nine midpoints of the bands of

frequencies between 500 and 2000 Hz.
388

CONTRACT YEAR 1976

OTICON

E-ll-V

Over-the-Ear

Moderate Power

SPECIFICATIONS

*Gain 45 dB

*SSPL 118 dB

Receiver Internal

SETTINGS AND ADJUSTMENTS

External: 1. Three position control

0 - Off

M - Microphone

T - Telephone

2. Volume Control

3. Tone Control

L - Low frequency emphasis

N - Normal

H - High frequency emphasis

4. Continuously variable gain/output control from 30 dBHL

minimum to 70 dBHL maximum.

BATTERY DATA

Type 675

Voltage 1.4

Two week supply with 16 hours of hearing aid use per day: 3 batteries

*The indicated data represent the mean values on the physical measurements made on samples of this hearing aid model by the National Bureau

of Standards and the Biocommunications Laboratory, University of Maryland,

according to their cited procedures. Gain and SSPL output are specified

with a tolerance of plus or minus 2 dB.

NOTE: Underlined items denote those Specifications and /or Settings and

Adjustments used in the physical measurement procedure to obtain the

reported statements of gain, SSPL, and frequency response.

*The reported gain represents the mean gain for three samples of the

model, computed using the values at the nine midpoints of the bands of

frequencies between 500 and 2000 Hz.

I
389

CONTRACT YEAR 1976

OTICON

E-16-U

Over-the-Ear

Mild Power

SPECIFICATIONS

*Gain 39 dB

*SSPL 112 dB

Receiver Internal

SETTINGS AND ADJUSTMENTS

External: 1. Three position switch

0- Off

M- Microphone

T- Telephone

2. Volume control

3. Variable tone control located on side of chassis

Fully clockwise - normal response

Two complete turns counterclockwise - maximum high

frequency response

BATTERY DATA

Type 675

Voltage 1.4

Two week supply with 16 hours of hearing aid use per day: 2 batteries

*The indicated data represent the mean values on the physical measurements made on samples of this hearing aid model by the National Bureau

of Standards and the Biocommunications Laboratory, University of Maryland,

according to their cited procedures. Gain and SSPL output are specified

with a tolerance of plus or minus 2 dB.

NOTE: Underlined items denote those Specifications and/or Settings and

Adjus tments used in the physical measurement procedure to obtain the

reported statements of gain, SSPL, and frequency response.

*The reported gain represents the mean gain for three samples of the

model, computed using the values at the nine midpoints of the bands of frequencies between 500 and 2000 Hz.
CONTRACT YEAR 1976

OTICON

S-ll-V

Eyeglass

Moderate Power

SPECIFICATIONS

*Gain 44 dB

*SSPL 118 dB

Receiver AFM-8

SETTINGS AND ADJUSTMENTS

External: 1. Two position control

0 - Off

+ - Microphone

2. Volume Control

3. M-T switch located on underside of temple

M - Microphone

T - Telephone

4. Tone control located on underside of temple

H - High frequency emphasis

N - Normal response

L - Low frequency emphasis

5. Continuously variable gain/output control from 30 dBHL

minimum to 70 dBHL maximum (located on underside of

temple)

.

BATTERY DATA

Type 675

Voltage 1.4

Two week supplj with 16 hours of hearing aid use per day: 3 batteries

*The indicated data represent the mean values on the physical measurements made on samples of this hearing aid model by the National Bureau

of Standards and the Biocommunications Laboratory, University of Maryland,

according to their cited procedures. Gain and SSPL output are specified

with a tolerance of plus or minus 2 dB.

NOTE: Underlined items denote those Specifications and/or Settings and

Adjus tments used in the physical measurement procedure to obtain the

reported statements of gain, SSPL, and frequency response.

*The reported gain represents the mean gain for three samples of the

model, computed using the values at the nine midpoints of the bands of

frequencies between 500 and 2000 Hz.
391

CONTRACT YEAR 1976

OTICON

375 PPX

On-the-Body

Strong Power

SPECIFICATIONS

*Gain 59 dB

*SSPL 131 dB

Receiver Air- CFD8

Cords Oticon 30"

SETTINGS AND ADJUSTMENTS

External

:

Three position control

M - Microphone

T - Telephone

0 - Off

Volume control

Tone control located on bottom of aid.

H - high frequency emphasis

N - flat frequency response

L - low frequency emphasis

Internal: None

BATTERY DATA

Type

Voltage

1015E

1.5

Two week supply with 16 hours of hearing aid use per day: 2 batteries

*The indicated data represent the mean values on the physical measurements made on samples of this hearing aid model by the National Bureau

of Standards and the Biocommunications Laboratory, University of Maryland,

according to their cited procedures. Gain and SSPL output are specified

with a tolerance of plus or minus 2 dB.

NOTE: Underlined items denote those Specifications and/or Settings and

Adj us tments used in the physical measurement procedure to obtain the

reported statements of gain, SSPL, and frequency response.

*The reported gain represents the mean gain for three samples of the

model, computed using the values at the nine midpoints of the bands of

frequencies between 500 and 2000 Hz,
CONTRACT YEAR 1976

392

PHONIC EAR

HC 527 LW

Body

Compression

SPECIFICATIONS

*Gain 62 dB

*MPO 120 dB

Receiver AT 16 W

Cords AT 50

SETTINGS AND ADJUSTMENTS

External: 1. Two position on-off switch

0 - Off

1 - On

2. Three position switch

M - Microphone

M/T - Microphone-telephone combination

**Audio - for use with external audio input

3. Continuously variable tone control (remove plug cover)

L - maximum low frequency emphasis

N - normal response

H - maximum high frequency emphasis

4. Continuously variable automatic volume control (AV)

(remove plug cover) . Varies from 1 to 1_. Turn control counterclockwise to position 1.

With aid turned on, adjust the AV control to MCL while

talking loudly. Increase volume with screwdriver until

patient indicates discomfort, then decrease volume

slightly. Replace plug cover.

**5. Audio input (on bottom of aid)

**To be used in combination when utilizing external sound

source, e.g., radio, TV, etc.

BATTERY DATA

Rechargeable nickel-cadmium cell (aid is supplied with charger)

.

Charging ; The charger may be connected continuously to a 110 volt

outlet without damaging it. For recharging, place the aid with cord

attached in the pocket and close it. A red light remains on while the

aid is charging. Maximum charging time is 18 hours; however, an overnight charge of 12 hoursgives approximately 35 hours of use. An overnight

charge every two days is recommended.

*The indicated data represent the mean values on the physical measurements made on samples of this hearing aid model by the National Bureau of

Standards and the Biocommunications Laboratory, University of Maryland,

according to their cited procedures. Gain and SSPL output are specified

with a tolerance of plus or minus 2 dB.
PHONIC EAR (Cont'd)

HC 527 LW

NOTE: Underlined items denote those Specifications and/or Settings and

Adjustments used in the physical measurement procedure to obtain the

reported statements of gain, SSPL, and frequency response.

*The reported gain represents the mean gain for three samples of the

model, computed using the values at the nine midpoints of the bands of

frequencies between 500 and 2000 Hz.
394

CONTRACT YEAR 1976

PHONIC EAR

HC 527 SEW(H)

Body

Compression

SPECIFICATIONS

*Gain 62 dB

*SSPL 119 dB

Receiver AT16W

Cords AT50

SETTINGS AND ADJUSTMENTS

External: 1. Two position on-off switch

0 - Off

1 - On

2. Continuously variable automatic volume control (AV)

(remove plug cover) . Varies from 1 to 1_. Turn

control counterclockwise to position 1. With aid

turned on, adjust the AV control to MCL while talking

loudly. Increase volume with screwdriver until

patient indicates discomfort, then decrease volume

slightly. Replace plug cover.

3. Audio input (on bottom of aid) (inoperable on this aid).

To be used in combination when utilizing external

sound source, e.g., radio, TV, etc.

BATTERY DATA: Rechargeable nickel-cadmium cell (aid is supplied with

charger)

.

Charging : The charger may be connected continuously to a 110 volt outlet without damaging it. For recharding, place the aid with cord attached

in the pocket and close it. A red light remains on while the aid is

charging. Maximum charging time is 18 hours; however, an overnight charge

every two days is recommended.

*The indicated data represent the mean values on the physical measurements made on samples of this hearing aid model by the National Bureau

of Standards and the Biocommunications Laboratory, University of Maryland,

according to their cited procedures. Gain and SSPL output are specified

with a tolerance of plus or minus 2 dB.

NOTE: Underlined items denote those Specifications and/or Settings and

Adjustments used in the physical measurement procedure to obtain the

reported statements of gain, SSPL, and frequency response.

*The reported gain represents the mean gain for three samples of the

model, computed using the values at the nine midpoints of the bands of

frequencies between 500 and 2000 Hz.
CONTRACT YEAR 1976

QUALITONE

TSPNB

Eyeglass

BICROS

SPECIFICATIONS

*Gain 58 dB

*SSPL 130 dB

Receiver Internal

SETTINGS AND ADJUSTMENTS

External: 1. On-off switch incorporated in battery compartment

2. Volume control

3. Tone control - Telephone switch

Hx - full low cut position

N - normal position

T - telephone

Internal: Output can be cut by 5 dB by removing the screw located

on the underside of the aid where it rests on top of the

ear.

BATTERY DATA

Type 675

Voltage 1.4

Two week supply with 16 hours of hearing aid use per day: 3 batteries

*The indicated data represent the mean values on the physical measurements made on samples of this hearing aid model by the National Bureau oJ. Standards and the Biocommunications Laboratory, University of Maryland,

according to their cited procedures. Gain and SSPL output are specified

with a tolerance of plus or minus 2 dB.

NOTE: Underlined items denote those Specifications and/or Settings and

Adjustments used in the physical measurement procedure to obtain the

reported statements of gain, SSPL, and frequency response.

*The reported gain represents the mean gain for three samples of the

model, computed using the values at the nine midpoints of the bands of

frequencies between 500 and 2000 Hz.
396

CONTRACT YEAR 1976

QUALITONE

UFO

Over-the-Ear

Mild Power

SPECIFICATIONS

*Galn 31 dB

*SSPL 112 dB

Receiver Internal

SETTINGS AND ADJUSTMENTS

External: On-off switch incorporated in voliime control

BATTERY DATA

Type M13

Voltage 1.4

Two week supply with 16 hours of hearing aid use per day: 3 batteries

*The indicated data represent the mean values on the physical measurements made on samples of this hearing aid model by the National Bureau

of Standards and the Biocommunications Laboratory, University of Maryland,

according to their cited procedures. Gain and SSPL output are specified

with a tolerance of plus or minus 2 dB.

*The reported gain represents the mean gain for three samples of the

model, computed using the values at the nine midpoints of the bands of

frequencies between 500 and 2000 Hz.
CONTRACT YEAR 1976

RADIOEAR

1040

Eyeglass

BICROS

SPECIFICATIONS

*Gain 51 dB

*SSPL 126 dB

Receiver Internal

SETTINGS AND ADJUSTMENTS

External: 1. On-off switch incorporated in battery compartment

2. Volume control

3. Mi crophone- telephone switch on top of temple

Internal: 1. Tone Control (rear screw in battery compartment)

(see below)

2. Gain Control (forward screw in battery compartment)

(see below)

POSITION TONE CONTROL

(LF CUT © SOOHz)

GAIN CONTROL

(GAIN CUT)

1 FULLCCW OdB OdB

2 - 5dB -11 dB

3 FULL CW -12 dB -22 dB

Low frequency and gain cuts other than those specified are possible by

rotating the adjustment screws to points between the positions indicated above. The tab always remains aligned with the slot. The instrument is shipped with the tone control at position 1 for maximum LF response and the gain control adjusted for 55 dB

HAIC gain.

BATTERY DATA

Type 675

Voltage 1.4

Two week supply with 16 hours of hearing aid use per day: 3 batteries

*The indicated data represent the mean values on the physical measurements made on samples of this hearing aid model by the National Bureau
RADIOEAR (CONT'd)

1040

of Standards and the Biocoinmunications Laboratory, University of Maryland,

according to their cited procedures. Gain and SSPL output are specified

with a tolerance of plus or minus 2 dB.

NOTE: Underlined items denote those Specifications and /or Settings and

Adjustments used in the physical measurement procedure to obtain the

reported statements of gain, SSPL, and frequency response.

*The reported gain represents the mean gain for three samples of the

model measured at 1000 Hz.
399

CONTRACT YEAR 1976

RADIOEAR

1050

Over-the-Ear

Moderate Power

SPECIFICATIONS

*Gain 54 dB

*SSPL 127 dB

Receiver Internal

SETTINGS AND ADJUSTMENTS

External: 1. On-off switch incorporated in battery compartment

2. Volume control

3. Microphone- telephone switch

Internal

;

1.

2.

Tone Control (forward screw in battery compartment)

In - Full low frequency response

Out - Reduced low frequency response

Output Control (rear screw in battery compartment)

In - Maximum output

Out - Reduced output

BATTERY DATA

Type 675

Voltage 1.4

Two week supply with 16 hours of hearing aid use per day: 3 batteries

*The indicated data represent the mean values on the physical measurements made on samples of this hearing aid model by the National Bureau

of Standards and the Bio communications Laboratory, University of Maryland,

according to their cited procedures. Gain and SSPL output are specified

with a tolerance of plus or minus 2 dB.

NOTE: Underlined items denote those Specifications and/or Settings and

Adjustments used in the physical measurement procedure to obtain the

reported statements of gain, SSPL, and frequency response.

*The reported gain represents the mean gain for three samples of the

model, computed using the values at the nine midpoints of the bands of

frequencies between 500 and 2000 Hz.
CONTRACT YEAR 1976

REXTON

4112

Over-the-Ear

Compression

SPECIFICATIONS

*Gain 35 dB

*SSPL 114 dB

Receiver Internal

SETTINGS AND ADJUSTMENTS

External

:

1.

2.

3.

4.

On-off switch

Volume control

Compression adjustment

N - Normal

C - Full Compression

Frequency response control

L - Normal response

H - High frequency emphasis

BATTERY DATA

Type M13

Voltage 1.4

Two week supply with 16 hours of hearing aid use per day: 3 batteries

*The indicated data represent the mean values on the physical measurements made on samples of this hearing aid model by the National Bureau

of Standards and the Biocommunications Laboratory, University of Maryland,

according to their cited procedures. Gain and SSPL output are specified

with a tolerance of plus or minus 2 dB.

NOTE: Underlined items denote those Specifications and/or Settings and

Adj us tments used in the physical measurement procedure to obtain the

reported statements of gain, SSPL, and frequency response.

*The reported gain represents the mean gain for three samples of the

model, canputed using the values at the nine midpoints of the bands of

frequencies between 500 and 2000 Hz.
401

CONTRA.CT YEAR 1976

SIEMENS

28 E-MP-HF

Over-the-Ear

CROS

SPECIPICATIONS

*Gain

*SSPL

Receiver

Cord

47 dB

117 dB

Internal

160-160

SETTINGS AND ADJUSTMENTS

External: 1. On-off switch incorporated in battery compartment

2. Volume control

3. Microphone-telephone switch

Caution: Cord is polarized. A significant reduction in gain occurs if flat portion of plug is not on top.

Internal

;

Continuously variable tone control (located in battery

compartment of receiver side.)

High—maximum high frequency emphasis

Normal—normal frequency response

BATTERY DATA

Type

Voltage

675

1.4

Two week supply with 16 hours of hearing aid use per day: 2 batteries

(Requires one battery in each side)

*The indicated data represent the mean values on the physical measurements made on samples of this hearing aid model by the National Bureau

of Standards and the Biocommunications Laboratory, University of Maryland,

according to their cited procedures. Gain and SSPL output are specified

with a tolerance of plus or minus 2 dB.

NOTE: Underlined items denote those Specifications and/or Settings and

Adjustments used in the physical measurement procedure to obtain the

reported statements of gain, SSPL, and frequency response.

*The reported gain represents the mean gain for three samples of the

model measured at 2000 Hz.
CONTRACT YEAR 1976

SONOTONE

670 BX

BodyExtra Strong Power

SPECIFICATIONS

*Gain

*SSPL

Receivers

Cords

72 dB

142 dB

Air - 4121RD

Sonotone 600:61 - Interchangeable for air and bone receivers,

SETTINGS AND ADJUSTMENTS

External: 1. On-off switch incorporated in volume control

2. Three position switch:

M - Microphone

MT - Microphone and Telephone

T - Telephone

Internal: Four triple position switches located in the battery

compartment

1. Mode: F - full gain

A - AVC

L - 6-8 dB gain reduction

High Emphasis:

Low Emphasis:

A. Power Limiting:

N - full low response

1 - additional emphasis above 1200 Hz

2 - additional emphasis above 2400 Hz

N - full high response

A - additional emphasis below 1000 Hz

B - additional emphasis below 500 Hz

P - full power output

R - 3 1/2 dB reduction

S - 7 dB reduction

BATTERY DATA

5. Additional Frequency Response Modifications;

(Inserts located in battery compartment)

No insert - full frequency response

Blue insert - slight low frequency cut

Red insert - moderate low frequency cut

White insert - maximum low frequency cut

Type

Voltage

132

2.6

Two week supply with 16 hours of hearing aid use per day: 4 batteries
403

SONOTONE (Cont'd)

670 BX

*The indicated data represent the mean values on the physical measurements made on samples of this hearing aid model by the National Bureau

of Standards and the Biocommunications Laboratory, University of Maryland,

according to their cited procedures. Gain and SSPL output are specified

with a tolerance of plus or minus 2 dB.

NOTE: Underlined items denote those Specifications and/or Settings and

Adj ustments used in the physical measurement procedure to obtain the

reported statements of gain, SSPL, and frequency response.

*The reported gain represents the mean gain for three samples of the

model, computed using the values at the nine midpoints of the bands of

frequencies between 500 and 2000 Hz,
404

CONTRA.CT YEAR 1976

TELEX

331H

Over-the-Ear

High-Pass

SPECIFICATIONS

*Gain 15 dB

*SSPL 119 dB

~ Receiver Internal

SETTINGS AND ADJUSTMENTS

External: 1. On-off switch incorporated in volume control

2. Variable tone control located on top of transmitter:

Full counterclockwise setting - full range response

Full clockwise setting - reduction of low frequencies

Internal : None

BATTERY DATA

Type Ml

3

Voltage 1.4

Two week supply with 16 hours of hearing aid use per day: 3 batteries

*The indicated data represent the mean values on the physical measurements

made on samples of this hearing aid model by the National Bureau of

Standards and the Biocommunications Laboratory, University of Maryland,

according to their cited procedures. Gain and SSPL output are specified

with a tolerance of plus or minus 2 dB. Gain was measured with open

earmold using Zwislocki coupler in KEMAR. This procedure necessitated

the use of reduced volume control setting.

NOTE: Underlined items denote those Specifications and/or Settings and

Adjustments used in the physical measurement procedure to obtain the

reported statements of gain, SSPL, and frequency response.

*The reported gain represents the mean gain for three samples of the

model, computed using the values at the six midpoints of the bands of

frequencies between 1000 and 2000 Hz.
405

CONTRACT YEAR 1976

TELEX

Model 400 Telecros

Eyeglass

CROS

SPECIFICATIONS

*Gain 45 dB

*SSPL 117 dB

Receiver Internal

Wireless Cros - the signal is transferred by radio frequency electromagnetic

coupling and may be fitted with any frame front.

SETTINGS AND ADJUSTMENTS

External: 1. Receiver side on-off switch incorporated in volume

control located on receiver side.

2. Microphone side on-off switch incorporated in con- tinuously variable tone control wheel located on microphone side.

3. Volume control located on receiver side.

4. Continuously variable tone control - located on microphone side. Forward rotation of tone control wheel

provides progressively greater low frequency cut.

CAUTION: Tone control must be rotated forward slightly

to activate microphone.

Internal : None

BATTERY DATA

Type S76

Voltage 1.5

Two week supply with 16 hours of hearing aid use per day: 4 batteries

Note: Battery in each temple required; however, battery life in

temple with microphone only is estimated at 240 hours.

*Ihe indicated data represent the mean values on the physical measurements made on samples of this hearing aid model by the National Bureau of

Standards and the Biocommunications Laboratory, University of Maryland,

according to their cited procedures. Gain and SSPL output are specified

with a tolerance of plus or minus 2 dB.

*The reported gain represents the mean gain for two samples of the model

measured at 1000 Hz.
CONTRACT YEAR 1976

ZENITH

AWARD

On-the-body

Mild Power

SPECIFICATIONS

*Gain 41 dB

*SSPL 117 dB

Receiver N-5

SETTINGS AND ADJUSTMENTS

External: 1. On-off switch incorporated in volume control

2. Two position tone control

Full - normal response

High - high frequency emphasis

Internal : None

BATTERY DATA

Type "N" cell

Voltage 1.5

Two week supply with 16 hours of hearing aid use per day: 2 batteries

*The indicated data represent the value on the physical measurements

made on one sample of this hearing aid model by the National Bureau of

Standards and the Biocommunications Laboratory, University of Maryland,

according to their cited procedures. Gain and SSPL output are specified

with a tolerance of plus or minus 2 dB.

NOTE: Underlined items denote those Specifications and/or Settings and

Adjustments used in the physical measurement procedure to obtain the

reported statements of gain, SSPL, and frequency response.

*The reported gain represents the mean gain for three samples of the

model measured at 1000 Hz.
407

CONTRACT YEAR 1976

ZENITH

CROS

Eyeglass

SPECIFICATIONS

*Gain 29 dB

*SSPL 121 dB

Receiver Internal

SETTINGS AND ADJUSTMENTS

External: 1. On-off switch incorporated in battery compartment.

2. Volume control

BATTERY DATA

Tyipe M41

Voltage 1.4

Two week supply with 16 hours of hearing aid use per day: 4 batteries

NOTE: Only one battery in the temple housing the receiver is needed.

*The indicated data represent the mean values on the physical measurements made on samples of this hearing aid model by the National Bureau

of Standards and the Biocommunications Laboratory, University of Maryland,

according to their cited procedures. Gain and SSPL output are specified

with a tolerance of plus or minus 2 dB.

Gain was measured with open earmold using Zwislock coupler in KEMAR.

*The reported gain represents the mean gain for three samples of the

model, computed using the values at the nine midpoints of the bands of

frequencies between 500 and 2000 Hz.
CONTRACT YEAR 1976

408

ZENITH

Pacemaker

Over-the-Ear

Moderate Power

SPECIFICATIONS

*Gain 52 dB

*SSPL 127 dB

Receiver Internal

SETTINGS AND ADJUSTMENTS

External; 1.

2.

3.

4.

On-o££ switch incorporated in battery compartment

Voliraie control

Microphone - Telephone switch

Tone Control - below T/M switch

- Low Cut

O - Normal (CAUTION: Do not attempt to rotate

switch beyond these two positive stops.)

Continuously variable power control - Full power to 12 dB

reduction with no loss of gain (screw on underside of aid).

To make any power output changes, first rotate the control

(with slip-clutch) at least one full counterclockwise

turn to reach the Full Power position (two red dots at

about 8 o'clock.)

MP HP—

r?

.LP fXl

Internal: None

POWER

FP - Full Power

HP - High Power - 3 dB reduction

MP - Medium Power - 6 dB reduction

LP - Low Power - 9 dB reduction

RP - Reduced Power - 12 dB reduction

BATTERY DATA

Type 675

Voltage 1.4

Two week supply with 16 hours of hearing aid use per day: 3 batteries

*The indicated data represent the mean values on the physical measurements

made on samples of this hearing aid model by the National Bureau of Standards

and the Biocommunications Laboratory, University of Maryland, according to

their cited procedures. Gain and SSPL output are specified with a tolerance

of plus or minus 2 dB

.

NOTE: Underlined items denote those Specifications and/ or Settings and

Adjustments used in the physical measurement procedure to obtain the

reported statements of gain, SSPL, and frequency response.

*The reported gain represents the mean gain for three samples of the

model, computed using the values at the nine midpoints of the bands of

frequencies between 500 and 2000 Hz.
409

CONTRACT YEAR 1976

ZENITH

Vocalizer III

Body

Strong Power

SPECIFICATIONS

*Gain 63 dB

*SSPL 135 dB

Receiver Air - Y5

Cords Zenith - S88705 (interchangeable for air and bone receivers)

SETTINGS AND ADJUSTMENTS

External: 1. On-off switch incorporated in volume control

2. Microphone - Telephone

M - Microphone

MT - Microphone and Telephone

T - Telephone

3. Variable power control with slip clutch (just above

receiver cord receptacle) from full on to 10 dB

reduction.

Full clockwise setting - (S) maximum power output

Full counterclockwise setting - minimum power output

Internal: Tone Control switch is located in the battery compartment

N - Normal, LC - Low Cut

BATTERY DATA

Type 401

Voltage 1.5

Two week supply with 16 hours of hearing aid use per day: 4 batteries

*The indicated data represent the mean values on the physical measurements made on samples of this hearing aid model by the National Bureau

of Standards and the Biocommxmications Laboratory, University of Maryland,

according to their cited procedures. Gain and SSPL output are specified

with a tolerance of plus or minus 2 dB.

NOTE: Underlined items denote those Specifications and/or Settings and

Adjus tments used in the physical measurement procedure to obtain the

reported statements of gain, SSPL, and frequency response.

*The reported gain represents the mean gain for three samples of the

model, computed using the values at the nine midpoints of the bands of

frequencies between 500 and 2000 Hz.

* U. S. GOVEP.'SUEyi: PETSTTSC OrnCE : 1376 O - 210-851 (640)


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