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Unity 3.1.3 and static at end of prompt recordings

Hi - <br><br> We just upgraded to unity 3.1.3 and I noticed when recording greetings, call handlers and prompts, that there is a static sound at the end of the recording. I'm not sure if this is just a left over from the old version (2.4.6) or not - suggestions are welcome.<br><br>Thanks,<br> Gerri<br><br>


Re: Unity 3.1.3 and static at end of prompt recordings

This has to do with a problem in the AGC logic in 3.1(x)... short story is it's always trying to bring the volume level of all recordings to around -26 dB (by default) and in the case of silence at the end of a recording this causes some "pop" since it's really cranking up very quiet "hiss" from around -50 dB or less to -26.

In 3.1(4) getting ready to roll out the door the updated AGC libraries are smart enough to allow you to set the threshold at which it will not try to adjust the volume... by default this will be -45 dB but is adjustable. It also has logic in there to allow you to set the maximum amount of adjust it'll attempt (i.e. don't adjust up or down more than 10 dB to avoid distortion). Both of these issues contribute to the popping you're hearing at the end of recordings...

You can disable AGC until 3.1(4) hits the streets if it's a serious issue for you... If 2.4.6 was working for you ok, you can disable the AGC value and adjust the WAV record/playback boosts as appropriate until 3.1(4) hits the streets and then you'll want to use the updated AGC which works much better than using static gain/reduction in record levels does...

Jeff Lindborg
Unity Technical Lead/Answer Monkey
Cisco Systems (new page for Unity support tools and scripts)

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Re: Unity 3.1.3 and static at end of prompt recordings

Thanks for the reply - actually what I thought I would do is make sure none of the settings from 2.4.6 carried over, so I downloaded the setvolume program and made sure everything was set to -26db - that seemed to fix the problem. Thanks!


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