Re: NSSpeechRecognizer and Speech Recognition calibration
Re: NSSpeechRecognizer and Speech Recognition calibration
- Subject: Re: NSSpeechRecognizer and Speech Recognition calibration
- From: "Michael Ash" <email@hidden>
- Date: Fri, 26 Dec 2008 23:24:14 -0500
On Fri, Dec 26, 2008 at 5:56 AM, Christopher Corbell
<email@hidden> wrote:
> I'm working on an accessibility app for the visually impaired and was hoping
> to use NSSpeechRecognizer.
>
> I've found it extremely difficult to get NSSpeechRecognizer to behave
> predictably on my system. Does anyone on the list have experience with this
> class & success with the Speech Recognition system preference panel? Any
> tips or tricks?
>
> I find that that calibration dialog for the Speech Recognition settings
> doesn't work at all for me. I'm using a pretty standard external microphone
> (built-in to a Logitech Webcam) with an intel Mac Mini. I can see my signal
> just fine and I'm speaking clearly in as accent-neutral a way as I can, and
> still none of the test sentences ever highlights. Is a headset mic
> typically required, or is there some other gotcha here?
>
> When I give NSSpeechRecognizer a very small and unambiguous command set, I
> find it badly misses the mark. For example I might have "Play", "Next", and
> "Stop" in my command set, and it will interpret "Next" as "Play", but it
> will never interpret "Play" as a command - pretty unusable, I'm hoping it's
> just a calibration issue.
I'm afraid I don't know a lot about this stuff, but since nobody else
has answered yet, I'll give it a shot.
>From what you describe I'd guess that your gain is not set well. You
need a good strong signal when you speak, but it absolutely must not
clip. If it's too quiet then I think that the recognizer won't realize
when you're speaking, or won't be able to understand what you're
saying when you do. If it's clipping then it will get a lot of
distortion. Try to make it so that your speech just reaches the top of
the green area.
I've never used speech recognition extensively but I have played
around with it a fair amount, and with a decent microphone that's
properly calibrated, I haven't really had much trouble with it
misunderstanding me, certainly not to the degree which you describe.
You might also try recording yourself and then playing it back. Listen
to see how it sounds. If it's distorted or otherwise of low quality
then that will hurt recognition badly.
> One last note - is there any way to do proper dictation with this class or
> will it only recognize the preset command list you give it? I'm thinking
> for example of prompting for a file name to save to, or a term to search on
> - it would be nice to have true dictation, otherwise I'll resort to
> providing an alphabet as a command set so the user can spell it out
> (assuming I can get that to work).
Alas, no dictation. The great thing about Apple's speech recognition
is that it's speaker-independent and requires no training. However the
state of the art for such things is that dictation requires training
to a particular speaker's voice before it can work. So Apple's
recognizer, by virtue of its capabilities in other areas, loses out on
this capability. You'll have to go with your alphabet command set or
some other idea that works with a predefined set of recognizable
phrases.
Mike
_______________________________________________
Cocoa-dev mailing list (email@hidden)
Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden