New Post: Alaw Pcm Conversion & MixingStream32 or MixingStream16

the best way to troubleshoot issues like this is to write to Wave file at different points in your stream. So for example, write ConversionStream1 to WAV and see if that sounds OK.

Also, you don't need to use CreateCustomFormat to create a PCM waveformat. Just use new WaveFormat(8000,1);