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Selection accuracy, lengths in 10ths of a milisecond?
Posted: Tue May 10, 2011 9:10 pm
by noodleman1
Hi there,
I'm trying to analyse a sound wave cluster which is very short, and the hh:mm:ss + miliseconds format doesn't quite cut it.
Is there a way to view the length of the selected part of an audio clip in a more detailed way? The selection certainly is more accurate than the format it's displayed in, as it never snaps from one milisecond to the other. However, I can't get that information displayed.
Any suggestions?
Thanks in advance

Re: Selection accuracy, lengths in 10ths of a milisecond?
Posted: Tue May 10, 2011 10:49 pm
by steve
Select either "Samples" or "hh:mm:ss + samples" as the time format.
Ensure that "Snap to" is not selected.
Re: Selection accuracy, lengths in 10ths of a milisecond?
Posted: Wed May 11, 2011 12:19 pm
by noodleman1
Hi Steve,
thank you for your quick reply, could you tell me more about those samples? Can I somehow convert the samples to miliseconds (be it manually or via audacity)?
I've never really used Audacity for anything before, so if you could explain how 'samples' work or link me to a page about them that'd be nice

.
Thanks a lot
Re: Selection accuracy, lengths in 10ths of a milisecond?
Posted: Wed May 11, 2011 5:15 pm
by steve
See here for the basics of digital audio:
http://en.wikipedia.org/wiki/Digital_audio
The sample period is the smallest unit of time in digital audio. If the sample rate of the audio is 44100 Hz, then that means that there are 44100 sample values each second. If you zoom in close enough on an audio track in Audacity, you will see a series of dots - each dot represents one sample value. The time distance between each dot would be 1/44100 second (just over 0.00002 seconds).
Re: Selection accuracy, lengths in 10ths of a milisecond?
Posted: Wed May 11, 2011 9:00 pm
by noodleman1
Ah that clears things up then, thank you, I take it the value at the top right in the grey track box (to the left of the actual track) is my sample rate (says 48kHz)? I just used the built in record feature for this soundclip, don't know if that has any set rates to it..
Re: Selection accuracy, lengths in 10ths of a milisecond?
Posted: Wed May 11, 2011 10:17 pm
by steve
Left end of the track in the "Track Control Panel", below the track name, it will say "mono" or "stereo" followed by the track sample rate. If the sample rate is 44100 Hz, then there are 44100 samples every second. If the track sample rate is 48000 Hz, then there are 48000 samples every second.
Re: Selection accuracy, lengths in 10ths of a milisecond?
Posted: Thu May 12, 2011 7:23 am
by noodleman1
Yes that was what I was referring to, should be fine then, thanks a lot for your all of your help, really appreciate it.
