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"Digital Recordings' new CD the "AUDIO-CD" is a brilliant step forward
..."AUDIO-CD" is extraordinary and a most ingenious solution to making
universal hearing testing cheap, reliable and effective....It makes the
testing of hearing a simple home project which can be to the benefit of
many people who suffer from partial hearing loss due to noise in the
workplace or very loud music during their recreation. Digital Recordings
is to be congratulated on taking advantage of modern technology in this
ingenious way." Prof.Hugh Jones, H.W. Jones and Assoc., England
... MORE customer testimonials
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If
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you frequently visit bars with live music
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go to rock concerts often
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listen to your Walkman loud enough for others to hear
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If
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you spend summer days on a boat with an outboard engine
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or love spending winter days riding a snowmobile
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If
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you often work with power tools
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are often exposed to high levels of carbon monoxide
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are undergoing a long antibiotic treatement
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THEN
YOU ARE IN
DANGER OF
SUFFERING
A
HEARING
LOSS
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Why? Because each of these activities subjects you to factors that can
damage your hearing. These include excessive sounds, certain chemicals and
some medications.
Why should you be concerned? Because good hearing is important in everyday
life, at work and at home. Good hearing keeps you safe when crossing the
street or hiking in the woods. It allows you to communicate effectively
with family, friends and colleagues. And it brings joy -- the sound of
children laughing, music, nature. Therefore, it makes good sense to protect
it. In some cases, you can use ear protection. But, since this is not always
possible, or often regarded as unnecessary, there is another way to make
sure your hearing stays in top shape.
Introducing
![[ hearing testing with AUDIO-CD ]](aud_logo.gif)
a compact disc that offers an easy and inexpensive
method for detecting hearing loss early, allowing you to take preventive
and corrective action.
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How is AUDIO-CD used for hearing testing?
AUDIO-CD provides anyone -- for the first time ever -- with an easy-to-use,
self-administered hearing test right in the comfort of your home. The test
is performed over a range of 24 frequencies -- from 20 Hz, the lowest
frequency humans can hear, to 20,000 Hz, the highest frequency humans can
hear. All you need to perform the test is a CD player and a set of
headphones or earphones.
How is hearing ability tested with AUDIO-CD?
Very easily!
Sitting in a quiet room with headphones on, you
- calibrate the volume level in the headphones using the SCT (Special
Calibration Tone) (*);
- then, assess the left ear by listening to test tones and
recording the passge of time before each tone becomes audible
(use the CD's timer
to track the elapsed time);
- once all the tones are listened to, turn the headphones around and repeat
on the right ear.
- as the last step, the noted times are charted either by hand on the graph
included in the AUDIO-CD booklet or, automatically, if they are typed on this form.
(*)
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The Special Calibration Tone included on the AUDIO-CD
allows for volume calibration with +/- 3 dB accuracy. If higher accuracy
or objective calibration is required this can be accomplished
with our inexpensive
semi-professional coupler DR1-R
and a Radio Shack Sound Level Meter.
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![[ DR1-R coupler ]](../coupler/dr1-r.gif)
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The graph below shows a sample chart of hearing test results. This chart
is referred to as an audiogram. The "x"s
indicate the left ear results, the "o"s indicate the right ear results.
The grey line indicates the "ideal" results, which are the same for both ears.
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How are hearing test results interpreted?
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It's easy!
The time (measured in seconds) that passes before the test tone
is heard represents the intensity (measured in dB) of the tone at the point
the tone is heard. Therefore, if it takes 10 seconds for the tone to be
heard, the intensity of the tone at this point is 10 dB. This intensity is
referred to as the "hearing threshold" for the tone. The purpose of one's
hearing test is to find hearing thresholds for all of the test tones, chart
them, and then compare the charted results against the "ideal" hearing
thresholds.
An upward deviation of more than 10 dB from an "ideal" threshold indicates
a hearing loss. The severity of a hearing loss can be determined based on
the provided table. Any concerns with the hearing test results should be
brought to the attention of an audiologist or acoustician.
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over 70 dB
Severe |
55 - 69 dB
Moderately Severe |
40 - 54 dB
Moderate |
25 - 39 dB
Mild |
10 - 24 dB
Slight |
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Use this table for determining the severity of hearing loss.
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How can hearing testing with AUDIO-CD help prevent hearing loss?
Permanent hearing loss, often referred to as Permanent Threshold Shift (PTS),
can be caused by exposure to excessive sounds,
certain chemicals and some
medications. The sad fact is that, once damaged,
hearing never gets better. Continued exposure to factors that cause hearing
loss will make matters worse. Degradation is gradual. There is usually no
pain or other alarming symptoms. Often, hearing loss goes unnoticed until
it starts interfering with verbal communication. At this point, damage to
hearing is already significant.
A regular check of hearing ability (once every 6 months, for example), is the only
truly effective method for identifying the early signs of hearing loss.
This allows you to take preventive or corrective steps, while damage to
hearing is still in the early stages.
The first audiogram should be used as a reference point and all consecutive
audiograms should be compared against it. The series of audiograms will
help to uncover any downward trends in one's hearing ability and identify
the factors causing hearing loss.
AUDIO-CD is also ideal for determining temporary hearing loss, often referred to
as Temporary Threshold Shift (TTS). This type of
hearing loss usually disappears within 16 to 18 hours after prolonged
exposure to moderate levels of sounds, chemicals or medications. A series
of episodes of temporary hearing loss, with insufficient time for recovery
between exposure, will eventually cause permanent hearing loss. Therefore,
it is important to understand their causes. AUDIO-CD is often the only
possible or practical solution for detecting temporary hearing loss. It
allows you to test hearing ability right after exposure to sources of damage.
To determine the presence, and to assess the magnitude, of temporary
hearing loss, the test results should be compared against the reference
audiogram.
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Who benefits the most from using AUDIO-CD for hearing testing?
AUDIO-CD is of benefit to both general
public and health care professionals. In particular it is of great use to
- those whose job depends on good hearing (audio engineers, sound
engineers, musicians, doctors, pilots, radio operators, telephone
operators, drivers, divers);
- those who are exposed to excessive noise at work (stone cutters, machine
operators, mechanics, construction workers, carpenters, farmers)
- members of the armed forces and police departments (for in-the-field
testing)
- hunters and gun users
- anyone exposed to loud sounds, music, chemicals,
medications, radiation
- researchers in the fields of acoustics, psychoacoustics, audiology, psychology,
speech pathology, biology (especially for testing of hearing
in animals)
as well as all those who value their hearing. Politicians are excluded, since they
do not listen anyway.....:-)
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What do others think about AUDIO-CD?
The following testimonial is typical of those
who have used AUDIO-CD:
" The quality of the stimuli (i.e. the test tone) is very good and the
procedure to find
HTs (i.e. Hearing Thresholds) is very clever (my colleague - Dr. Brad McPherson - used the
word 'ingenious'). Clearly, given the limitations of testing someone's
hearing on his/her own hi-fi at home, it would have been very difficult
to find an easier procedure to use." Dr.Valter Ciocca, University
of Hong Kong, Hong Kong
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Interested in buying your own copy of
AUDIO-CD?
AUDIO-CD is offered for $49.95 CAD (for non-commercial use)
plus shipping and handling. It can be ordered via the Web
by filling out this
Secure Order Form.
Methods of payment
include Visa, Master Card, American Express, money order or wire transfer. Orders will
be filled after the funds are received.
The price of $49.95 CAD applies to non-commercial use only.
Those interested in obtaining a commercial licence are asked to
contact Digital Recordings directly.
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Suggested Reading:
Those interested in more information on AUDIO-CD should read the
"Technical Specifications".
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Online Free
Hearing Testing
WWW Hearing Test
the first comprehensive and entirely web-based hearing test
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