[asterisk-users] Speech recognition in asterisk using google voice API

sean darcy seandarcy2 at gmail.com
Wed Jan 4 13:48:22 CST 2012


On 1/4/2012 2:26 PM, Lefteris Zafiris wrote:
>>
>> Works beautifully. Amazing job Lefteris. Thanks.
>>
>> The best result I got in probability was 0.9725632 by saying, "hello". I
>> think there is some non-phonetic logic built-in as well. I tried, "1, 2" and
>> I got "0.86534226" in accuracy. While I tried "1, 2, 3, 4, 5" I got,
>> "0.97256315". Probably Google sees the pattern?!
>>
>> What are some of the other tricks (if any) or consideration that one should
>> make while creating a strong speech recognition enabled IVR?
>
> Google accepts sound files at any sampling rate (up to 44.1kHz) so if
> you can use some wideband codec ( eg g722)
> It can greatly improve the sound quality and the detection rates. For
> now the script supports 8kHz and 16kHz sampling rates
> for recording and it can be set by editing the scripts user defined
> parameters ( the variable $samplerate).
> Anything that improves the recording sound clarity will help, a good
> phone, low background noise level etc.
> I have also read that normalizing the recording and setting the gain
> to -5 db improves detection rates. I m experimenting with this at the
> moment and there will be some new code soon (as soon as i get sox
> working in RHEL/Centos 5 :P ).
>

This is really spectacular. Thanks.

I'm running Fedora 15, so I can use flac or sox. Any reason to prefer 
one over the other?

sean





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