Audiometer For Accurate Hearing Loss Evaluations

By Helene Norris


The audiometer is a machine used by audiology centers and ENT specialists to measure hearing loss in patients. More often than not, it is a part of the audiometry test equipment used for administering various tests. Audiometers now available in the market come in both hardware and software form.

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.

The device can be a standalone machine or hooked up to a computer that controls the output and records all the feedback. These machines are made using different kinds of technologies, depending on the intended usage. Some are portable, others handhelds, and still others may be full-fledged systems that are meant to be used in one place. All of them are either bone-conduction or air-conduction audiometers.

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.

The hardware audiometers that are used by hospitals, audiology centers and researchers are expensive, but incredibly accurate and reliable. It's important to make sure these machines are calibrated regularly so that the tone heard by the subject matches the level displayed on the machine. Calibration requirements also ensure standardized testing and results regardless of where the machine is being used.

Audiometry software installed on desktops or laptops can be used at home by anyone, and it is relatively affordable. It is more difficult to calibrate the software, which also means that accuracy is hard to achieve. It is, however, still good enough to allow a subject to self-test and determine if their hearing is normal or needs medical treatment.

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.

Industrial audiometric testing also needs the same audiometers, and the process followed is about the same as described above. However, subjects are not required to go the clinic or audiology center. Rather, a mobile lab packed with all the equipment and technicians is dispatched to the industrial facility to evaluate how workers are being affected by the onsite 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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