A remote microphone signal is obtained from a remote device, and a local microphone signal from a local device. A difference between strength of the remote microphone signal and strength of the local microphone signal is determined. An output audio signal is produced to drive a speaker in the local device. If the difference is greater than a threshold, then the local and remote microphone signals are applied to two input channels, respectively, of a two channel noise suppressor which produces the output audio signal, but if the difference is less than the threshold after a certain delay since the difference was greater than the threshold, then only the remote microphone signal is applied to a single input of a single channel noise suppressor which produces the output audio signal. Other aspects are also described and claimed.