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 work on the same principle. They produce a sound which is listened to by the person being tested. The volume and frequency of the test sound can be controlled, thereby providing a standard against which the person's hearing can be measured. The frequency or pitch is measured in Hertz (Hz) and the volume is measured in decibels (dB). Pitch describes how high or low a sound is. For example, a soprano singer achieves a high pitch, while a bass guitar plays at a low pitch. Volume measures the intensity of the sound.
The purpose of the test is to determine the sensitivity of the person's hearing. This is why the typical setup of an audiometer is a pair of headphones attached by wires to a machine or a computer. Once the person's sensitivity has been established, the necessary steps can be taken to rectify the person's hearing or to prevent further damage.
The trick in using an audiometer is to make it produce exactly the right sounds. In order to do this, the audiometer needs to be calibrated, in the same way as a musical instrument needs to be tuned. Calibration, or re-calibration, needs to be done frequently in order to ensure maximum reliability.
There are several ways in which an audiometer gets put out of tune, such as incorrect handling of the equipment, an environmental temperature which is too high or too low, the equipment's age, and excessive use. Like a musical instrument, an audiometer is a sensitive piece of equipment. In order to operate with acceptable accuracy at all times, an audiometer should be re-calibrated every year.
There are basically two kinds of audiometer: the hardware and the software type. The hardware type consists of a device wired to a pair of earphones. The software type, on the other hand, is based on a computer program. Both have the same function. The key difference between the two is that software-based audiometers never need re-calibration because they are digitally programmed. They can also achieve a deeper level of accuracy because they are computerized. However, they are more tricky to deploy because of idiosyncratic factors unique to each PC and user.
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.