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AUDIO-CD Hearing Test

"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


Featured on the TV program "The Doctors"
The Doctors
The Doctors

  • you frequently visit bars with live music
  • go to rock concerts often
  • listen to your Walkman loud enough for others to hear
  • you spend summer days on a boat with an outboard engine
  • or love spending winter days riding a snowmobile
  • you often work with power tools
  • are often exposed to high levels of carbon monoxide
  • are undergoing a long antibiotic treatement


    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.


    [ hearing testing with AUDIO-CD ]

    a compact disc that offers an easy and inexpensive method for detecting hearing loss early, allowing you to take preventive and corrective action.

    How is AUDIO-CD used for hearing testing? 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.


    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.

    [ DR1-R coupler ]

    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.


    How are hearing test results interpreted?

    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.

    over 70 dB
    55 - 69 dB
    Moderately Severe
    40 - 54 dB
    25 - 39 dB
    10 - 24 dB
    Use this table for determining the severity of hearing loss.
    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.

    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 ... :-)

    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

    Interested in buying your own copy of AUDIO-CD?

    AUDIO-CD is offered for $49.95 CAD plus shipping and handling.

    Payment Methods Money order, wire transfer
    Transaction Currency Canadian Dollars ($CAD)
    Order Processing Within 5 business days from the day payment is received
    Shipment World-wide; via Canada Post air mail

    To place an order using wire transfer or money order fill out this

    The price of $49.95 CAD applies to non-commercial use only. If you are interested in obtaining a commercial licence please contact Digital Recordings directly.

    Suggested Reading: Those interested in more information on AUDIO-CD should read the "Technical Specifications".
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