I think it's because the camera is not just an optical path, but a display where the picture is refreshed over and over. The light isn't always on when the image refreshes as the light signal isn't at the same frequency as the refresh rate. It's two rates beating together -- you see the difference.

I don't think that the way that the original poster was using wav files is the way that you are thinking. The OP was using the wavs in order to use his headphone jack on his phone in order to play an audio file that would be sent out the headphone jack and converted into an IR signal to control a TV.

I can't imagine being in the situation that you are in and would love to figure out how to build an application that would work for you!! For you it would need to use simple speech to trigger a command. The "best" way would be to have you talk and then an application send a command to a control processo, like Crestron, that would send out IR, RS232, or IP control. That would be the most flexible option. I would think that Android would have the most possiblity for this application.

Google already has Voice Actions available to control a phone not sure it works on the tablets. It does a bunch of different stuff but I don't think that you can launch an app from it. I'm sure that if Android developers were made aware of how this type of app could change the lives of people, then they would come up with something. Have you tried posting on Android developer forums?

I know this is an old post, however, I have a device from Audex which helps people who are hearing impaired. This device is a SA-PS3-C Infrared emitter.

[Link: ebay.com]

I believe the opposite is true though. With a detector, it could be used as a measuring device, measuring that which is unseen by the human eye and then converted to a wav format.