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Accurate Calibrated Audiometer For Hearing Loss Evaluations

By Helene Norris


The audiometer is used by audiology centers and ear, nose and throat (ENT) specialists for measuring hearing loss. It is usually one of the methods performed as part of an audiometry test. Both hardware and software-based audiometers are now available from various providers.

The hardware version is a simple machine that produces pure tones at controlled intensities. During hearing loss evaluations, the machine's output is heard by the subject in one ear at a time through a pair of headphones. The subject has a feedback button that enables them to respond when they hear the tone.

Audiometers may be standalone machines or can be integrated with a computer that controls it and offers a full suite of software tools and functionality. These devices come in many different types and use varying technologies. For example, some are bone-conduction systems while others are air-conduction based. It may be handheld, portable or a full-fledged machine intended for use in a single location.

Software-based audiometers produce the same tones, and subjects respond in exactly the same way. The main difference is that the software has a stored database of sounds. The tones are simply piped into the headphone through the system's sound card.

Audiometers built as a physical machine are more expensive, but provide the high degree of accuracy that hospitals, researchers and audiology centers need. Regular calibration is still essential to ensure the tone heard and the level shown in the display match each other. Proper calibration is also necessary to ensure a global standard for testing and measurement of hearing levels.

Audiometry software is much more affordable by comparison, and can be used by anyone even at home. Calibration is not so easy for the software, which means there will be some accuracy loss. It's still quite useful for regular self-testing, and will let the subject know if any further checkups and medical treatment are needed.

Regardless of whether it is software or hardware, the aim here is to determine at what point the subject fails to hear the tone. Physicians use this device as a useful aid for diagnosing hearing problems and treating them. The suggested course of action may vary, but usually includes a thorough cleaning of the ears to remove obstructions, followed by ear drops and maybe even a hearing aid and/or surgery if the problem is more serious.

Audiometers may also be used for industrial audiometric testing. The procedure followed is essentially the same as described above. The difference is in the fact that the subject or patient doesn't come to the clinic. Instead, a full-fledged mobile audiometry testing lab and technician are brought to the industrial facility to test the hearing levels of noise-exposed workers.

The results obtained in these industrial tests are not simply meant to evaluate the hearing ability of workers from a health point of view. It is also used to find out whether the facility requires additional noise-muffling systems. Sometimes, these checkups are provided under group health plans. In any case, an audiometer used for industrial applications must be calibrated perfectly to within a small fraction of a decibel.




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