Issue 133 August 2001
Listening Chips

Delving into voice recognition and chips that listen, Tom takes a look at the current state of development. With pioneer Sensory leading the way, he discovers there’s potential for designing unique applications.

Start • In The Realm Of The Sensory • Lip Reader • Walk The Talk • Soft Sounds • Yak Attack • Hearing Aid • Sources & PDF

Years back in May of 1993, I wrote an article called "Talking Chips" (Circuit Cellar 34) describing the then emerging digital voice recorder ICs. Besides offering a high-tech replacement for the bulky, balky mechanical voice recorders of yore, the innovation spawned entirely novel applications, such as greeting cards that speak your own personally recorded message.

As you might guess, this month I’m covering a chip that can listen. There’s definitely the potential for inspiring a lot of exciting and unique applications, some of these are more obvious than others.

I think voice recognition technology has gotten a bad reputation because it’s stereotyped as a magic bullet designed to supposedly put that inspired hack of the typewriter age, the crusty but lovable QWERTY keyboard, out of its misery. Through the brute force application of MIPS and megahertz, progress has been made, but chips and software can’t yet achieve the accuracy and speed required for transcribing natural gab.

On reflection, replacing keyboards may be one of those situations where if it can be done, it will be done, and then you’ll see if it should have been done. As someone who types a lot, I have a few observations.

First, when writing an article, typing is the least of my worries. The real work is studying datasheets, fooling with boards, trying experiments, and so forth. The hardest of all is giving creative birth to the words I want to say, not just typing them.

Even imagining a perfect voice recognition system for my PC, I’m not convinced. Try this experiment. Think of a sentence or phrase and then type it while saying it aloud. As someone who can type at a decent rate, I can key in the words at nearly a normal speaking cadence. Only by slurring the words together in a blur does speaking demonstrate more top-end throughput. The human brain demonstrates its formidable skill by being able to parse such frenetic blabber, but it drives automated recognition systems nuts.

Besides, have you ever given a long speech or talked vociferously at a party for hours on end? It’s tiring. I presume it wouldn’t be long before folks would get up in arms over the other CTS, carpal tonsil syndrome.

Overlooked in the dubious quest to kill QWERTY is the fact that there are less glamorous (but imminently practical) voice recognition applications that do become feasible with incremental advances in technology. Besides such likely candidates as car phones, automated phone systems, and toys, I can imagine a lot of handy (make that no hands) products.

For example, when using a scope or logic analyzer, I invariably end up needing to punch a switch or twist a dial even as both hands are frozen probing the rat’s nest. It would be great if I could just say, for example, "External Trigger Channel 2" instead of the more flowery phrases I find myself using in that situation.