An audiogram is a graph that shows how well an individual can hear various pitches or frequencies in a quiet environment. A hearing threshold is the softest sound that the individual can detect at least 50% of the time.
There are two axes on the audiogram. The vertical axis represents intensity, or loudness, of sound in decibels (dB). The lowest levels are listed at the top of the graph and grow higher further down the graph. 0 db, at the top of the graph, represents the softest level of sound that a person with normal hearing will be able to hear at any frequency. An adult is classified with normal hearing if they can hear between 0 and 25 dB.
The horizontal axis represents frequency (pitch) of sound and is measured by Hertz (Hz). Similar to piano keys, the lowest pitch is on the left-hand side and grows higher the further you progress to the right. Speech typically ranges from 250 to 6000 Hz. Consonants such as F, S, H, TH are among the highest frequency sounds, as shown on the degrees of hearing loss chart [LINK].
When the individual in testing responds to a sound that they hear, the hearing professional will place a mark at the intersection of the pitch and loudness (frequency and intensity) that the individual heard. A red “O” is frequently used to show responses for the right ear, and a blue “X” is used to represent responses from the left ear. The “O”s are connected with a red line to show hearing levels in the right ear, while a blue line connecting the “X”s show hearing levels in the left ear.
Note: The audiogram solely measures the ability to hear in quiet, not the quality of hearing noise, and every hearing loss is unique. It is important to consult with a hearing health professional to understand the various aspects of your hearing, such as speech recognition, that may not be revealed in an audiogram.
Hearing happens in the brain. Although our ears are able to capture noise and transfer the vibrations to our brain, communication relies on what are brain does with those vibrations to convert them into noise that we understand. Many individuals first notice an issue with their hearing when they begin to have difficulty understanding speech in noisy environments.
To further test if a hearing loss is present, a hearing health professional may conduct a speech reception threshold (SRT) test. This test is only for children and adults who can talk. The individual will be given words through headphones that they are asked to repeat. The hearing health professional will record the softest speech that the individual is able to repeat correctly. A consultation between the individual and hearing health professional will occur after the SRT test to help the individual understand if they have a hearing loss that causes difficulty understanding speech.
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