input-output characteristic
7.24 input-output characteristic. For a hearing aid, a single frequency plot of coupler SPL on the ordinate as a function of input SPL on the abscissa with equal decibel scale divisions on each axis.
Gaussian noise
7.23 Gaussian noise. Noise for which the amplitudes of some measure such as instantaneous voltage in an electrical signal or instantaneous sound pressure in an acoustical signal may be described by a normal (Gaussian) distribution.
gain
7.22 gain. Amount of amplification provided between the input signal and the output signal of a system. The parameter for which the gain is being specified, i.e., time-mean-square sound pressure, sound power, electrical voltage, or electrical power, should be stated. Annotation Gain is often expressed in decibels as equal to ten times the logarithm to the base ten of the ratio of time-mean-square output voltage or output sound pressure to time-mean-square input voltage or input sound pressure, respectively.
occluded ear simulator
7.21 occluded ear simulator. Device which approximates the acoustic transfer impedance of the inner part of the human ear canal, from the tip of an ear mold to the eardrum.
supra-aural earphone
7.20 supra-aural earphone. Earphone applied externally to the outer ear and intended to rest on the pinna.