I am developing an application that will detect a high frequency sound played by TV. My TV is capable of playing mp3, wma and wav files. When I generate a high frequency audio sound file (18 kHz to 21 kHz) whit Audacity. Than convert it to mp3, wma or wav the sound on this frequencies is cut of, so I can't detect it any more.
Can audio files in these formats carry sounds on this high frequencies? If yes, how can i generate them?