System and method for automatic adjustment of reference gain

A method of automatically adjusting a reference gain for a reference channel of a channel selector further comprising a plurality of audio input channels for receiving respective near end audio signals captured by a plurality of microphone elements, the reference channel receiving a far end audio signal as a reference signal, the method comprising:

• determining an echo level in a first audio input channel of the plurality of audio input channels by:
• determining a coherence level based on the far end audio signal and a first near end audio signal received in the first audio input channel, and
• based on the coherence level being greater than a preset threshold, using a signal energy level of the first near end audio signal as the echo level in the first audio input channel;
• determining a reference gain amount for the reference channel based on the echo level in the first audio input channel;
• applying the reference gain amount to the far end audio signal prior to receipt in the reference channel as the reference signal;
• and
• making gating decisions for the plurality of audio input channels by comparing each of the audio input channels to the reference channel.

A system, comprising:

• a channel selector comprising:
• a reference channel for receiving a far end audio signal as a reference signal, and a plurality of audio input channels for receiving respective near end audio signals from a plurality of microphone elements, the channel selector configured to make gating decisions for the plurality of audio input channels by comparing each of the audio input channels to the reference channel;
• and
• a reference gain adjuster configured to:
• determine an echo level in a first audio input channel of the plurality of audio input channels by:
• determining a coherence level based on the far end audio signal and a first near end audio signal received in the first audio input channel, and
• based on the coherence level being greater than a preset threshold, using a signal energy level of the first near end audio signal as the echo level in the first audio input channel;
• automatically determine a reference gain amount for the reference channel based on the echo level in the first audio input channel, and apply the reference gain amount to the far end audio signal prior to receipt in the reference channel as the reference signal.