Adaptive noise state update for a voice activity detector

A method of updating a noise state of a voice activity detector (VAD) for indicating an active voice mode and an inactive voice mode, said method comprising:

• receiving an input signal having a plurality of frames;
• determining an average minimum energy based on two or more of said plurality of frames;
• determining a current minimum energy based on a current frame of said plurality of frames;
• updating said noise state of said VAD if said average minimum energy is less than said current minimum energy minus a first predetermined value;
• and
• updating said noise state of said VAD if said average minimum energy is greater than said current minimum energy plus a second predetermined value.

A voice activity detector (VAD) for indicating an active voice mode and an inactive voice mode, said VAD comprising:

• an input configured to receive an input signal having a plurality of frames;
• an output configured to indicate said active voice mode or said inactive voice mode;
• wherein said VAD is configured to determine an elapsed time since the last update of a noise state of said VAD;
• wherein said VAD is configured to update said noise state of said VAD if said elapsed time exceeds a predetermined time;
• wherein said VAD is configured to determine an average minimum energy based on two or more of said plurality of frames;
• wherein said VAD is configured to determine a current minimum energy based on a current frame of said plurality of frames;
• wherein said VAD is configured to update said noise state of said VAD if said average minimum energy is less than said current minimum energy;
• and
• wherein said VAD is configured to update said noise state of said VAD if said average minimum energy is greater than said current minimum energy plus a first predetermined value.

A voice activity detector (VAD) for indicating an active voice mode and an inactive voice mode, said VAD comprising:

• an input configured to receive an input signal having a plurality of frames;
• an output configured to indicate said active voice mode or said inactive voice mode;
• wherein said VAD is configured to determine an average minimum energy based on two or more of said plurality of frames;
• wherein said VAD is configured to determine a current minimum energy based on a current frame of said plurality of frames;
• wherein said VAD is configured to update a noise state of said VAD if said average minimum energy is less than said current minimum energy minus a first predetermined value;
• and
• wherein said VAD is configured to update said noise state of said VAD if said average minimum energy is greater than said current minimum energy plus a second predetermined value.