Improvement about Coherences and Multi-channels about cdr-dereverb

[andreas12345]

Hi,

1. the diffuse coherence is a pretty good approximation for most rooms. But it should also be possible to implement an online tracking of the noise coherence, e.g., by using a voice activity detector and estimating the coherence in noise-only segments.

2. You could simply compute the CDR from multiple microphone pairs in the array and use the average. Alternatively, you can use a maximum likelihood estimator for direct and diffuse power, which has a closed-form solution (assuming the noise coherence and direction of arrival is known): https://uol.de/fileadmin/user_upload/mediphysik/ag/sigproc/download/papers/SP2015_42.pdf

• Andreas