What Decibel Scale and Human Hearing Are

This section describes the decibel scale and the human hearing threshold.

The decibel scale is expressed in dB SPL.

The human ear can perceive pressure variation over a wide range of values starting from about 20 μPa (2x10^-6 Pa), which is the hearing threshold, to 20 Pa (2x10¹ Pa), which is the pain threshold.

The human ear can perceived sound with a frequency between 20 Hz and 20 kHz.