I need to transfer information through sound channel.I want to use speakers as the trasmitter and microphone as the receiver.But i dont want the output from the speakers in form of noise.I just want it to be transmitted.
As I understand, You want to make a wireless communication between two soundcards, but You don't want to use the audio speakers as transmitter, because it's noise level very high. Is this right ?
1. Use the low-noise speaker.
2. You can use the IR-LED, which modulates by the audio out, as transmitter, and photodiode, which connected to microphone in, as receiver. (Some times ago, i read the article about the photocamera shutter diagnostics due to photodiode connected to microphone-in of ordinary soundblaster - similar situation.)