Looking for audio shield which can play seperate audio on left & right channels

I have an Uno and I'm planning a project which will involve playing audio based on the input from a ultrasonic sensor. I'd like to have a plethora of different sounds to choose from, and for a given range of input values, play sounds from a particular group of sounds, sometimes simultaneously.

To this end, I'm looking for an audio shield which can play different audio files simultaneously on the left and right stereo audio channels (I'd like to have different sounds coming from different places). I found an audio shield that does this, the BeatVox by Rugged Circuits: http://www.ruggedcircuits.com/html/beatvox.html. Unfortunately, it's out of stock, and upon emailing the company, I found out that they're not planning to make any more.

I like the idea of being able to play different audio on the left and right channels, because it seems like a frugal way to make use of the hardware. My preference would be to not have to buy separate shields for each audio channel. Does anyone know of another shield with this capability?

In case in initial project description wasn't clear enough: My plan is divide the possible input values from an ultrasonic sensor into a few categories. For each of these categories, there will be a list of audio files. From this list, different files will be randomly chosen to be played, on one of two (or maybe more) audio channels.

can you just record mono left and a different mono right and play the combined in stereo?

You are going to need two separate audio modules to do this. Even if you could find one shield, it would still have two on it.

How long do you think each clip may be? How much many seconds/minutes total would you expect?

There are different ways to do it depending on that. You could use the ISD chips from Winbond, two MP3 modules, or maybe one MP3 module and some type of simple audio generation from the Arduino directly.

If you are ready to settled for "decent quality" audio output you can try this. http://hackerspace-ffm.de/wiki/index.php?title=SimpleSDAudio

Separate shield not necessary. Combine two mono tracks as a stereo track and play with this.There is a stereo setting in it.Just go with that.