voice rt sound files longer than requested

[sparkle814]

As a matter of fact, none of the recordings are 300 ms. The shortest seems to be about 440; is that normal? Some are around 800 or 900, and then there are also the ones I mentioned already, that are several seconds long.

[jarvis24]

Well let's try to tackle the duration issue first. Remember that rt:aud,rec,-300 will cause DirectRT to record the vocal response for an additional 300ms after the RT occurs. So if the RT is 200ms, you should get a voice clip that's around 500ms long. Alternatively, you can specify rt:aud,rec,300 to record for exactly (give or take) 300ms.

See also: www.empirisoft.com/directrt/help/directrt_samples_of12_voice_rts_.htm

[sparkle814]

Okay I think I see now. I had thought that it waited to start recording until the beginning of the voice response, but from what you said I guess it starts recording right away, then once the voice response occurs, it records for 300 more milliseconds.

In other words, if it took 30 seconds for the participant to give a voice response then the sound file would be 30.3 seconds long; is that correct?

Thanks very much!

[jarvis24]

Yes, that is correct.