[pulseaudio-discuss] Can module-echo-cancel reduce the background noise?

[Lin, Mengdong]

> > (1)     Reduce the echo of myself during audio recording in a room
> 
> I'm not sure about what you mean here precisely. But in general this
> isn't called echo, but feedback. The only difference between the two
> is that with echo you have a large (~ > 20ms) delay and you can here
> two distinct versions of the sound. With feedback the delay is in the
> order of a typical wavelength (~ < 5ms) and you can hear a (often
> high-pitched) ringing sound.
> 
> The obvious solution would be not playing back the recorded audio over
> the speakers. Is there any particular reason you want to hear
> yourself?

> And if the recording is for musical purposes, I'd strongly advise to
> get a decent microphone. I mean, when a band is performing on stage
> they can hear themselves over the monitor quite loud, but there's no
> feedback and no echo-cancelling is used. (wel actually there are
> devices called feedback-killers, but those are more automatic
> equalizers and are generally not used for music event, but rather for
> speech)
> 


Thanks a lot for the information! I have two use cases in my mind:
(a) If I speak in a large empty room and use a microphone to record my voice (no playing back), can PA module-echo-cancel reduce the echo/feedback?
   You mentioned to use a decent microphone, is such a microphone can reduce the feedback via its hardware?

(b) When I do a presentation in a hall (both recording and playing back, and maybe multiple speakers), can PA module-echo-cancel reduce the echo/feedback? 

Thanks
Mengdong