ffmpeg, I'm recording a talk, its audio with a semi-distant microphone. It makes sense to somewhat enhance the speech clarity, reduce background static and environmental noise, etc., in the most generic terms.
What combination of ffmpeg audio filters am I best advised to use to enhance recorded speech?
I'm currently using
to additionally attenuate the bass frequencies, and
compand=attacks=.05:decays=.05:points=-90/-90 -70/-90 -15/-15 0/-10:soft-knee=6:volume=-70:gain=10
to apply dynamic range compression and supposedly make the softer passages (above -70dB) louder and the louder ones more even.
I understand digital filters are not magic, but I'm looking for something more from ffmpeg's (or LADSPA's) repertoire to enhance the sound more, make it more resilient to noise, sporadic coughs, perhaps lose the acquired metallic aftersound ...
The Linux command line I'm using to test:
filters=' ...above filter lines, in sequence... ' arecord -q -r 11025 -f s32_le -c 1 -t wav - | ffmpeg -f wav -i - -af "$filters" -f wav - | aplay