I have an 44100 Hz file with human voice, stereo with 16Bit.
When convertig this to 8 kHz, mono I loose a lot of quality and have
some ground noise. I tried several sox options but without success.
Can somebody help….
best regards Thomas
You really need to remove the bass end of the spectrum before
downsampling to 8k/s. uLaw/ALaw sound pretty muddy and horrible if you
don’t do that, and the other common 8k/s codecs don’t sound any better.
Jean-Marc Valin wrote a little filtering utility for this purpose.