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Periodic sound sampling over time

Posted: Thu Oct 10, 2013 8:11 pm
by bgillesp
I am trying to find a feature which allows me to register ambient noise during the same 5 minutes every hour for 24 hours, leaving the microphone and its ampli connected permanently. Is this doable with the current timer features? If so, I haven't found how!
Thanks for this great software.

Re: Periodic sound sampling over time

Posted: Thu Oct 10, 2013 8:24 pm
by kozikowski
Timer Record isn't a program. It's a tool with little windows to put your time in. So you can't change it, although some enterprising soul might be able to whip something up in Nyquist.

Koz

Re: Periodic sound sampling over time

Posted: Thu Oct 10, 2013 8:26 pm
by kozikowski
leaving the microphone and its ampli connected permanently.
And computer. I would guess that even if you managed to get it to work, you wouldn't be able to use the computer for anything else. Audacity is a simple program and it likes running on simple computers.

Very few people have managed to make a surveillance computer out of Audacity. That's your Google search term.

Koz

Re: Periodic sound sampling over time

Posted: Fri Oct 11, 2013 1:49 am
by steve
If you are on Linux you can simply schedule arecord (or any other command line recorder) as a Cron task.
I doubt that there will be much interest is developing an Audacity feature to record for 5 minutes every hour.

Re: Periodic sound sampling over time

Posted: Fri Oct 11, 2013 6:03 am
by bgillesp
I'm not on Linux. For my need, the computer would indeed be dedicated to the sound surveillance operation. Would continuous recording over 24 hours not create enormous file? I could cut 5 minute samples from a large file using the timeline, I suppose.

Re: Periodic sound sampling over time

Posted: Fri Oct 11, 2013 7:19 am
by kozikowski
Isn't it a 13-1/2 hour limit for 44100, 16-bit, Stereo? Something like that? You should not use lower quality because the filtering and effects tools stop working well. WAV files poop out at either 2GB or 4GB and I forget which one is significant.

You really need software that's designed to do this.

Koz

Re: Periodic sound sampling over time

Posted: Fri Oct 11, 2013 1:54 pm
by steve
kozikowski wrote:Isn't it a 13-1/2 hour limit for 44100, 16-bit, Stereo?
For saving and re-opening Audacity projects, yes: http://wiki.audacityteam.org/wiki/Relea ... e_Projects
Longer projects can be created, but data will be lost if you try to save a project longer than this.
kozikowski wrote:WAV files poop out at either 2GB or 4GB and I forget which one is significant.
4GB is the limit for "normal" WAV files (equivalent to about 6.8 hours of CD-quality audio): http://en.wikipedia.org/wiki/WAV#Limitations
Some older Windows PCs have a 2 GB file size limit, but that is not very likely these days.
bgillesp wrote:I'm not on Linux. For my need, the computer would indeed be dedicated to the sound surveillance operation.
Then you probably need to use dedicated sound surveillance software.
bgillesp wrote:Would continuous recording over 24 hours not create enormous file
Yes it would, though if most of that time is silence, then you could use the "Sound Activated Recording" feature: http://manual.audacityteam.org/o/man/tr ... u.html#sar

Re: Periodic sound sampling over time

Posted: Fri Oct 11, 2013 5:03 pm
by kozikowski
use the "Sound Activated Recording" feature:
Which kills your "time of day" information. Audacity doesn't have timestamps or SMPTE Timecode unless you add it.

See:
Software designed to do this.

Koz