Absolute threshold of hearing
The absolute threshold of hearing (ATH), also known as the absolute hearing threshold or auditory threshold, is the minimum sound level of a pure tone that an average human ear with normal hearing can hear with no other sound present. The absolute threshold relates to the sound that can just be heard by the organism. The absolute threshold is not a discrete point and is therefore classed as the point at which a sound elicits a response a specified percentage of the time.
Average hearing thresholds in decibels (SPL) (the unit of 'dB(HL)' shown on the vertical axis is incorrect) are plotted from 125 to 8000 Hz for younger (18-30 year olds, red circles) and older adults (60-67 year olds, black diamonds). The hearing of older adults is shown to be significantly less sensitive than that of younger adults at frequencies of 4000 and 8000 Hz, corresponding approximately to the piano keys and tones of b′′′′ (B7) and b′′′′′ (B8), respectively. B8 is near the high end of the piano frequency range.
Hearing, or auditory perception, is the ability to perceive sounds through an organ, such as an ear, by detecting vibrations as periodic changes in the pressure of a surrounding medium. The academic field concerned with hearing is auditory science.
A cat can hear high-frequency sounds up to two octaves higher than a human.
