Techniques for distortion reducing multi-band compressor with timbre preservation

摘要

Distortion reducing multi-band compressor with timbre preservation is provided. Timbre preservation is achieved by determining a time-varying threshold in each of a plurality frequency bands as a function of a respective fixed threshold for the frequency band and, at least in part, an audio signal level and a fixed threshold outside such frequency band. If a particular frequency band receives significant gain reduction due to being above or approaching its fixed threshold, then a time-varying threshold of one or more other frequency bands are also decreased to receive some gain reduction. In a specific embodiment, time-varying thresholds can be computed from an average difference of the audio input signal in each frequency band and its respective fixed threshold.

主权项

1. A method for audio presentation by a playback device, the method comprising:
determining a first fixed threshold for a first frequency band; determining a first level of an audio signal within the first frequency, the first level being less than the first fixed threshold; determining a second level of the audio signal for a second frequency band, the second frequency band differing from the first frequency band; determining a third level of the audio signal for a third frequency band, the third frequency band differing from the first and second frequency bands; determining a second fixed threshold for the second frequency band; determining a third fixed threshold for the third frequency band; computing, by a processor of the playback device, a time-varying threshold for the first frequency band using the second level and the second fixed threshold, without contribution of the third level and the third fixed threshold, wherein the time-varying threshold is less than or equal to the first fixed threshold; attenuating the audio signal within the first frequency band based upon the time-varying threshold; and audibly presenting the attenuated audio signal by at least one output transducer of the playback device.