Equal loudness curves represent the sound intensity level required for a pure tone of any given frequency to be perceived as having the same loudness as a reference tone.
Describe the experimental procedure used to gather the data required to plot an equal loudness curve for a subject with normal hearing.
State the frequency range at which the normal human ear is most sensitive, and explain how this sensitivity is reflected in the shape of an equal loudness curve.
An acoustic engineer measures a background noise level of 64 dB64\text{ dB}64 dB inside a soundproof chamber. Calculate the acoustic intensity of this sound wave. The reference threshold of hearing is I0=1.0×10−12 W m−2I_0 = 1.0 \times 10^{-12}\text{ W m}^{-2}I0=1.0×10−12 W m−2.
