Re: Speech recognition system for Home automation.

[Marc_F_Hult <MFHult@xxxxxxxxxxxxxxxxxxxxx>]

On Sun, 09 Sep 2007 12:15:24 -0000, Soren <soren.skou.nielsen@xxxxxxxxx>
wrote in message  <1189340124.126635.118080@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>:

>Hi,
>
>I'm looking at possibilities of constructing a relatively cheap home
>speech recognition system to turn appliances on and off.

[snip]

>
>What I really need is a robust recognition system that works with
>microphones not placed directly in front of the speaker.. like in the
>corner of the living room.
>

Soren,

I've played with this for years and conclude that for me, the failure rate
is still usually too high. Depends in large part on one's tolerance level
for mistakes and, especially,  the need to repeat. I have 3-4 different
Crown PZM models, and other mics, gated mixers and have tried most of the
VR programs available through about 2005.

Some suggestions:

1) read this article about the "Myth of microphone reach"

	 http://www.shure.com/ProAudio/Products/us_pro_ea_myth

and this  approach to predicting speech to background noise ratio:

	 http://www.shure.com/ProAudio/Products/us_pro_ea_predicting

2) If you want to have more than one microphone, a gated mixer is a near
necessity. I have a bunch of extra 8-In 4-0ut Ivie 784 and 884 mixers for
sale on my personal Internet Home Automation and Porch sale here for about
7 cents on the dollar. The 884's have built-in mic preamps and auto gating.

www.ECONtrol.org/porch_sale.htm

I also have some new/unused small flat Sony pzm-style mics that are excess
to my needs that I will add to the Porch Sale for $5 each.

There is write up on the use of mixers in home automation here:

www.ECOntrol.org/audio.htm

This may be more tan you want now, but these projects have a way of growing
;-) It outlines a flexible, modest-cost approach to integrating all audio
signals,  input and output, used in HA including those for VR,
announcements, background music, intercom AV and so on -- here's the
important part for your need to control from across the room -- in a way
that maximizes the likelihood of successful VR because all the other
signals could be made to auto-mute when an initial VR command is received.
Of course it can be made to do a lot more than that.

HTH ... Marc

Marc_F_Hult
www.ECOntrol.org
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