https://packages.debian.org/jessie/fmit https://packages.debian.org/stretch/fmit
Here are the two current versions of it and I like it because it gives a little more control in tuning out noise and concentrate in what I want to measure. It is most probably electrical noise and fluctuations of voltage and/or frequency, which may get amplified to look like an unstable wave form. This part may be understood enough to leave it to the sound experts. What is interesting is that a mechanical vibration may actually cause electrical contacts on the whole system to create an instability within that electrical noise. One does not need to be a sound physicist to translate this into an effective microphone. How many pc's don't have panels that act as drums and amplify noise and transform noise into a mechanical vibration? No, there is no onboard mic, there are only two audio inputs front and back, and as I said trying this in 2 other systems with different debian builds had similar results (some noise registering and affected by abrupt vibration). Yes I have pavucontrol installed, pulseaudio and utils. PS Suddenly, the noises in one's head that nobody else hears are recorded by one's only true friend, the PC :)) :))) deloptes: > GiaThnYgeia wrote: > >> I don't see how the previous got linked to a previous thread so I am >> reposting with additional clarification. >> >> OK, I did some testing on an other machine with a testing installation, >> downloaded FMIT (an instrument tuner that will pickup audio input/analog >> and tell you all kinds of stuff about the wave that is fed). >> Same exact behavior, hardware only lists two audio inputs and are both >> unplugged. The lower the db threshold for sound recording the more >> apparent the sound becomes. Each knock on the box shows corresponding >> amplification of that noise. >> >> Ok, so I picked up 2-3 live debian based USB sticks I have. I plugged >> then in to 3 different machines, downloaded FMIT and run it. Similar >> results. So it has nothing to do with my configuration of stuff. I say >> if some software is picking up sound from your environment and records >> it when no inputs are plugged in I would call this a "security" issue >> not a malfunction. >> >> What is there MORE to post so it can be reproduced? Blank live debian >> installations adding FMIT in 3 machines Jessie + Stretch (one on UPS, >> one on mains-plug, on laptop) if you allow it to see a wide spectrum of >> frequencies it records noise (mostly hi-freq) and only hardware inputs >> are unplugged. Where is the noise coming from? >> >> It probably has nothing to do with the program itself but its >> dependencies and some code feeding in wrong data as audio input. But it >> is actual sound > > I was interested in your mainboard - perhaps it has integrated mic. > > Do you have pavucontrol installed? Go to input devices and mute the mic > > regards > > -- "The most violent element in society is ignorance" rEG