Ok well another way to call a sound file (which would work better if you're using a key press) is to:
1st: Right click the sound file, click on 'Linkage' and then click the 'export for Actionscript' button and name it whatever you want ('mySound' for example).
Then you can now make an instance of it in your actionscript by putting code like this on the main timeline:
<i>var soundname:Sound = new Sound();
soundname.attachSound("mySound");</i>
Then you can call the following functions to call that sound to start or stop:
<i>
soundname.start(0, 0);
soundname.stop();
</i>
Hope it helps, let me know if you don't understand how to use this, and please be specific