Absolute Threshold of Hearing

The Absolute Threshold of Hearing (ATH) is the volume level at which one can detect a particular sound 50% of the time. If one has a low absolute threshold, it means that he is able to detect small amounts of stimulation, and thus is more sensitive. If one has a high absolute threshold, then he requires more stimulation and thus is less sensitive.

$T_{q} (f) = 3.64 * (\frac{f}{1000})^{-} 0.8 - 6.5 e^{-} 0.6 (\frac{f}{1000} - 3.3)^{2} + 1 0^{-} 3 (\frac{f}{1000})^{4}$

The following are curves of the ATH for several age groups over frequency. Zwicker approximated these curves from experiments on a number of subjects:

The ATH is the simplest property of human hearing to exploit when designing a psychoacoustics model.