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An audio frequency or audible frequency (AF) is a periodic vibration whose frequency is audible to the average human. The SI unit of frequency is the hertz (Hz). It is the property of sound that most determines pitch .
When the subject hears the sound, they indicate this by raising a hand or pressing a button. The lowest intensity they can hear is recorded. The test varies for children; their response to the sound can be indicated by a turn of the head or by using a toy. The child learns what to do upon hearing the sound, such as placing a toy man in a boat.
Audiogram. An audiogram is a graph that shows the audible threshold for standardized frequencies as measured by an audiometer.The Y axis represents intensity measured in decibels (dB) and the X axis represents frequency measured in hertz (Hz). [1]
Several psychophysical methods can measure absolute threshold. These vary, but certain aspects are identical. Firstly, the test defines the stimulus and specifies the manner in which the subject should respond. The test presents the sound to the listener and manipulates the stimulus level in a predetermined pattern.
The test is conducted in a sound booth using either a pair of foam inserts or supraural headphones connected to an external audiometer. The result of the test is an audiogram diagram which plots a person's hearing sensitivity at the tested frequencies.
Conventional audiometry tests frequencies between 250 hertz (Hz) and 8 kHz, whereas high frequency audiometry tests in the region of 8 kHz-16 kHz. Some environmental factors, such as ototoxic medication and noise exposure, appear to be more detrimental to high frequency sensitivity than to that of mid or low frequencies.
In the Weber test a vibrating tuning fork (Typically 256 Hz [7] or 512 Hz [8] used for Weber vibration test; 512 Hz used for Rinne hearing test) is placed in the middle of the forehead, above the upper lip under the nose over the teeth, or on top of the head equidistant from the patient's ears on top of thin skin in contact with the bone. The ...
The most common type of audiogram is the result of a pure tone audiometry hearing test which plots frequency versus amplitude sensitivity thresholds for each ear along with bone conduction thresholds at 8 standard frequencies from 250 Hz to 8000 Hz. A pure tone audiometry hearing test is the gold standard for evaluation of hearing loss or ...