plugin that records automatically when sound is heard?

[derekandrews]

Is there a plugin or feature of Audacity that can record an audio file when sound is detected---and then only shut off when there has been total silence for say 30 seconds to a minute? If not, I think I shall write such a plugin because it would be immensely useful to me.

[billw58]

Audacity 1.3.12 has sound activated recording: http://manual.audacityteam.org/index.ph ... references

Once you've set the threshold in the preferences, you can turn it on and off in the Transport menu: http://manual.audacityteam.org/index.ph ... t_Menu#sar

For information on plugins in Audacity see: http://wiki.audacityteam.org/wiki/Guide_for_Hackers

Improvements to the Sound Activated Recording function have been requested on the wiki feature requests page: http://wiki.audacityteam.org/wiki/Feature_Requests (scroll down to "Sound Activated Recording" in the "Highest Rated" section). There is a request for "Pre- and post-roll duration: define a duration to be recorded before the threshold-level sound occurs, and similarly a duration to be recorded after the input falls back below the threshold. Requires buffering of the recording for pre-roll, but is expected behaviour for this type of tool. (23 votes)." If this sound like what you'd like, I'll add a vote for you.

-- Bill

[derekandrews]

Yes, the pre-roll and post roll sound perfect for my purpose.

[waxcylinder]

Yes, the pre-roll and post roll sound perfect for my purpose.

In which case would you like us to add your vote to the Feature Requests page in the Wiki? Or you can do it yourself if yet enrol for a Wiki account.

WC

[derekandrews]

Yes, please do add a vote for me, that's what I was trying to say in the previous post.

[bgravato]

You may add a vote on that one for me too.

I was thinking about something like this today and I was trying this feature on audacity. One extra feature that I needed was to have timestamps of when the recording started/stopped. I want to know when certain events ocurr and beside recording them I need to know what time did they take place.

I'm going to google around and see if I can find any way of doing this in linux using sox or other app and I'll report here my findings...

[waxcylinder]

Both votes added.

WC

[bgravato]

I managed to get sox's rec to work as sound activated recorder, but it was a bit tricky...

First it was hard to make it record from the source I wanted, but that's probably due to my overly complex sound setup (3 sound cards + alsa + pulseaudio + jack + weird and complex .asoundrc).

Once I got over that, another tricky part is to understand how the silence effect on rec works... This blog page explains it quite well though: http://digitalcardboard.com/blog/2009/0 ... f-silence/

I did something like in example 3 on that page, but using decibel values instead of % for the threshold (something like -48d instead of 1%).

It will only record the first non-silent period and then stops. To make it record continously all sound ocurrances you'll have to write a small shell script with a continuous loop to create a new file everytime a new sound event ocurrs. The advantage of this is that, from the files' creation date/time I can tell when each sound event ocurred.

I'm wondering if it would be possible to make a plugin for audacity so that it would create a label with timestamps for each time a sound activated recording is started... would that be possible?