Jan 25th Simpsons Episode over digital TV transmission-alt audio

I flipped on the Simpsons last night using over the air digital tranmission here in Detroit (Channel 2-1, not sure what the exact channel # is), and they had an alternate audio channel going. Not sure if this was on purpose, but I flipped to DirecTV feed and that channel was not there.

It was interesting because the audio was of the normal sound, then each time the scene changed, it was a guy reading a description of the scene. For example "Homer, driving". "Lisa and Bart in the Front seat".

Must have been a mistake as I've never heard this before.

Don't know why it appeared, but that's an additional audio track for the visually impaired.

"Larry Bud" wrote in message news:[email]...

Somebody claiming to be [email] (Larry Bud) wrote in news:[email]:

This is the "Descriptive TV" service for the blind, in which the normal soundtrack has such descriptions added. Normally this is on the secondary audio track, accessed on most TVs via a button marked SAP or MTS. If your local station was airing the DTV service as the primary audio, *that* would be a mistake.

If you have the episode on tape, watch the opening again: in the shot where Homer is pulling into the driveway, there's a bug in the bottom left with a D and the three audio ) signs (similar the the closed captioning bug of a CC in a rectangle to which we've all become accustomed).