Accurate Calibrated Audiometer For Hearing Loss Evaluations

By Helene Norris


An audiometer is a machine used by ENT (ear, nose and throat) clinics and audiology centers to measure hearing loss. Audiometers are typically part of the equipment used during an audiometry test. There are both software and hardware-based audiometers available in the market.

Audiometers built as a physical device emit audio tones at varying intensities. During the hearing loss evaluation test, the machine's output is fed to headphones and heard in each ear separately by the subject. A feedback button that can be pressed enables the subject to acknowledge each tone as they hear it.

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 systems function in pretty much the same way, sending out a tone to the subject on a headphone and collecting feedback through a button. The difference is in the way the tone is generated. In this case, the software merely sends out stored tones to the computer's sound card.

Hardware audiometers used by professional audiology centers, hospitals and research centers are more expensive, but also highly accurate and more reliable. These machines must be calibrated regularly to ensure that the intensity of the tone heard by subjects accurately reflects the level shown on the device display. Calibration also ensures standardized testing and consistent results no matter where the machine is used.

Audiometry software may be used as an alternative to a whole new machine. It will be cheaper and can be used by anyone at home and without assistance. However, calibration of the software is much more difficult and accuracy harder to obtain. People can still use it for regular testing, and only seek expert medical opinion if they discover any hearing loss.

The point of all this, whether it is a software or hardware-based system, is to find out exactly when the subject stops hearing the tone. This helps physicians diagnose hearing problems and provide treatment. It usually involves at least a bit of ear cleaning and perhaps some ear drops, if not a hearing aid or even surgery.

Another major application for audiometers is industrial audiometric testing. The actual process is pretty much the same as the one described above. One of the key differences is the fact that patients don't visit the clinic. Instead, a mobile lab with the required equipment and technicians comes to the industrial facility for testing the hearing levels of workers who are constantly exposed to noise.

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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