3 The Hearing Process
The Response of the Ear to Different Frequencies
This is best shown graphically, as in Figure 8. Each line is an equal loudness curve. See below for an explanation of Phons.
The reference zero, a sound pressure level (SPL) of 0 dB, is taken to be a pressure of 20 μPa (0.000 02 N/m2).
The smallest change in frequency that can be detected is known as the frequency ...