Audio noise annoyance, what is it ?

[Linux-SWAT]

Hi,

I have this since a while in my loudspeakers, TV, audio system, etc. :
http://slackware.openpandora.org/tmp/audio-beep.ogg

It happens every 3mn or so.
I wonder if it could be linked to a phone communication tower near where I live.

 

[benoitb]

Could you try to spot the frequencies with some tools ? Maybe by opening your ogg file in a spectrum analyzer software. Could give a hint on what technology is causing this.

 

[Linux-SWAT]

From Ardour spectral analyser :
[doublepost=1478872733,1478872558][/doublepost]Definitely a 4kHz noise :

 

[sulu]

Do you have some portable device that works without mains power that is affected?
If so, you could try to capture the sound from different positions and try to pinpoint it via it's volume.

 

[FBnil]

I found this old piece of info, hinting that it could be bug where a device is renewing its DHCP lease over and over:
http://android.stackexchange.com/questions/21102/wifi-signal-drops-out-every-3-minutes

Tried to help searching for 4khz and 4000hz but: did not much found.

Ok, let's try more.... Here are some theories, from plausible... to... twilight zone...

There are some bird wailers (sounds to keep birds away), but they are not used in these months. Other pests have higher hz, so not audible to us.

Anti-frogman techniques are security methods developed to protect watercraft, ports and installations, and other sensitive resources both in or nearby vulnerable waterways from potential threats or intrusions by frogmen or other divers.
As humans hear best at that frequency... but you would have to live near a port for that...

cycle of 3 minutes is too long for radar or other swiping things.... however, here it gets weird:




"launched on 28 April 1999...The telescope's battery was accidentally overcharged and destroyed three days after the mission started..... the $20 million project was abandoned."
https://en.wikipedia.org/wiki/ABRIXAS
And this document tells us that "...ABRIXAS is rotating with a period of approximately 180 seconds...."
http://fas.org/spp/military/program/track/fgan.pdf

note to self: do not overcharge the Pyra...



Here is some technical info I am sure you already know:

http://www.randombio.com/interference.html
http://www.audio-technica.com/cms/site/d0c406516fd8b42b/

 

[NutNut]

 

[levi]

You say this comes out of your loudspeakers, TV and sound system. How many discrete systems is that? My TV is wired into my sound system for sound, and my speakers are connected to that to actually make noise, so I'd count that as one system.

 

[joachim]

I don't think its a phone tower signal (only one frequency). The phones are getting in contact once in a while so the net will know where the phone is when moving. My brother has his mobile near the radio and sometimes you can hear a hard "brrrrr" , a deeper signal with more frequencies (square wave)
no nice "sss" (sinus, single freq - as yours). You can try this by yourself.