Abstract: Techniques performed by a data processing system for operating a speaker disposed within a sealed enclosure herein include obtaining a first input signal to be output by the speaker; determining a first volume level associated with the first input signal; selecting a first Linkwitz Transform and a first Multiband Compressor (MBDRC) from volume- dependent configuration data based on the first volume level; generating a first intermediate signal by applying the first Linkwitz Transform to the first input signal to increase a low- frequency response of the speaker; generating a first output signal by applying the first MBDRC to the first intermediate signal by compressing the at least a portion of the first intermediate signal; and driving the speaker to produce first audio output using the first output signal.

Abstract: Ambient noise can be suppressed from a captured audio signal by detecting a parameter of a variable ambient noise source and determining a first power spectrum representing the variable ambient noise source based on the detected parameter. If the first power spectrum is compared to a second power spectrum that is determined for the captured audio signal, the two power spectra can be compared to identify a frequency range where net power of the first power spectrum and net power of the second power spectrum satisfy relativity criteria. Suppressing the audio signal within the identified frequency range has the effect of reducing degradation of a voice communication present in the audio signal.