>>480
NSSoundDelegateで再生終了時のdidFinishPlayingを拾ってリリーすれば良いんじゃない
-(void)playSE{
　　NSString*path= @"音パス";
　　NSSound *se = [[NSSound alloc] initWithContentsOfFile:path byReference:YES];
　　[se setDelegate:self];
　　[se play];
}
-(void)sound:(NSSound *)sound didFinishPlaying:(BOOL)aBool{
[sound release];
}