Audio signal processing

At least one computer readable device storing software for execution on an audio signal processing device having a loudspeaker component for outputting analogue audio signals, a microphone component for receiving analogue audio signals, and comprising an audio interface configured to receive in digital form any audio signal generated on the device for outputting via the loudspeaker component and to generate from the audio signal an outgoing audio signal in analogue form for supplying to the loudspeaker component, the audio interface configured, in generating the outgoing audio signal, to apply dynamic range compression controlled by the audio interface to the audio signal;

• wherein the software is configured when executed to:
• receive an incoming audio signal and generate from the incoming audio signal an audio signal in digital form by pre-processing the incoming signal, the pre-processing including:
• detecting one or more characteristics of the dynamic range compression applied by the audio interface;
• and
• based on the detected characteristics, applying initial nonlinear amplitude processing controlled by the software to the incoming audio signal to modify its power envelope;
• supply the generated audio signal to the audio interface for additional processing by the audio interface prior to output via the loudspeaker component including the dynamic range compression applied by the audio interface, wherein the initial nonlinear amplitude processing controlled by the software results in smoothing of the power envelope thereby reducing effects of dynamic range compression applied by the audio interface;
• and
• provide the generated audio signal for use as a reference in audio signal processing of audio signals received via the microphone component.

A software-implemented method performed in an acoustic system comprising a loudspeaker component for outputting analogue audio signals, a microphone component for receiving analogue audio signals, and an audio signal processing device comprising an audio interface configured to receive in digital form any audio signal generated on the device for outputting via the loudspeaker component and to generate from the audio signal an outgoing audio signal in analogue form for supplying to the loudspeaker component, the audio interface configured, in generating the outgoing audio signal, to apply dynamic range compression controlled by the audio interface to the audio signal, the method comprising:

• receiving an incoming audio signal and generating from the incoming audio signal an audio signal in digital form by pre-processing the incoming signal, the pre-processing including:
• detecting one or more characteristics of the dynamic range compression applied by the audio interface;
• and
• based on the detected characteristics, applying initial nonlinear amplitude processing controlled by the software to the incoming audio signal to modify its power envelope;
• supplying the generated audio signal to the audio interface for additional processing by the audio interface prior to output via the loudspeaker component including the dynamic range compression controlled by the audio interface, wherein the initial nonlinear amplitude processing controlled by the software results in smoothing of the power envelope thereby reducing effects of dynamic range compression applied by the audio interface;
• and
• providing the generated audio signal for use as a reference in applying acoustic echo cancellation to audio signals received via the microphone component, thereby cancelling echo from those signals.