Adaptive loudness control

摘要

Loudness control is performed by estimating the energy and loudness of an audio signal. Loudness of the audio signal is determined by decomposing the audio signal into multiple frequency bands at different center frequencies. The energy of the audio signal in each frequency band is calculated and converted to a loudness, using a function that models human loudness perceptions of audio energies at different frequencies. The loudnesses are summed to obtain the total loudness of the audio signal. A signal gain is calculated as a function of a loudness setting provided by a human listener, the estimated signal energy, and the total loudness of the audio signal.

主权项

1. A method, comprising:
receiving an input audio signal; determining a signal energy of the input audio signal; determining a band energy of the input audio signal for each of multiple frequency bands of the input audio signal; converting each band energy to a corresponding band loudness to produce multiple band loudnesses; summing the multiple band loudnesses to produce a signal loudness; receiving a loudness value specified by a human listener, wherein the loudness value indicates a desired relative audio loudness; multiplying the loudness value by a ratio of the signal loudness to the signal energy to produce a signal gain; amplifying the input audio signal by the signal gain to produce an output audio signal; and providing the output audio signal to a loudspeaker.