I don't think so. Everything you see and hear are downloaded and cached for faster access and there is no way to stop it happen.
An example is when you use radio.blog.club. They use the flash player to play the .rbs music. The .rbs file are downloaded to the harddrive as .rbs and if you rename it to .mp3 it will work on any device. Is it this you mean?
you would have to stream the audio, or make the audio into a swf and load it into a level. After the audio is finishing playing you can then have it unload the level/swf. (you can load different .swf's into levels) the audio only stays on the hard drive for the play time. google flash levels or load movie. if your using AS3 It might be different.