A Brief Explanation Of Audiometers

By Lana Bray


There is an irony in the fact that the ability to hear isn't one that gets much attention until it starts to fade. New technology in industry and developments in the entertainment industry have led to a more marked degree of hearing loss in society than was previously the case. In assessing and repairing this trend of damage, audiometers play an important role.

Every day, people are routinely exposed to extremely loud sounds, whether as part of their employment or recreation. Examples are heavy industry and loud music in entertainment venues. This type of exposure can result in gradual hearing decay. Preventing this decay involves the measurement of a person's hearing, and audio measuring devices are used in this process of measurement.

Audiometers all operate according to the same principle. The device produces a carefully controlled sound which is routed into the ears of the person being tested. The volume and frequency of the this sound are deliberately determined by the device, and the sound then becomes the yardstick by which the sensitivity of the person's hearing is measured. The volume of the sound is measured in decibels (dB) and the frequency (pitch) in Hertz (Hz). The louder a sound, the higher its decibel count, while frequency is an indication of pitch (high or low sounds).

This type of test is used to determine the degree of sensitivity of the person's hearing. A typical audiometer consists of a set of headphones which are connected to a machine or a computer. Once a reading has been determined, appropriate action can be taken in safeguarding and mending the person's hearing.

Of course, the audiometer needs to be adjusted so that the sounds it produces can be effectively controlled. This type of adjustment is called calibration, and it involves fine-tuning the machine so that the sounds it makes are genuinely pitched at the volume and frequency required. Calibration needs to be done on a regular basis for the machine to be reliably accurate.

Several factors make regular calibration necessary. The operating temperature of the machine, its age, rough handling and how often it is used all play a part in causing it to lose accuracy. This is similar to a musical instrument going out of tune. It is advisable to have an audiometer re-calibrated once a year.

At present there are two types of audiometer: the hardware and the software type. The hardware version consists of a stereotypical design: earphones plugged into a box or machine. The software type also uses earphones, but they are linked to a PC or other digital device. The most important difference lies in their respective performances. A software audiometer never needs re-calibration, just as a digital musical tuner can never go out of tune. Software devices can also produce more detailed readings, since they are digital. However, software audiometers are also harder to use accurately because they involve individualized on-board and hardware settings, which make calibration more difficult.

In a time of increasingly louder noises, it is important to be able to detect hearing loss. Audiometers have many industrial and household applications. They are a valuable complement to the steps that each person can take in safeguarding their own hearing.




About the Author: