使用AVAudioPlayer播放2个声音而不进行睡眠（）;

Question

我使用scrollview在AVAudioPlayer中播放了这2个声音。

问题在于sleep()正在创造滞后，我需要一种替代方案，在没有睡眠功能的情况下，更容易一个接一个地播放两个声音。

PS：文件的名称由用户所在的scrollView中的页面给出。

   if( nextPage!=6 )  {
    [scrMain scrollRectToVisible:CGRectMake(0, nextPage*250, scrMain.frame.size.width, scrMain.frame.size.height) animated:YES];
    pgCtr.currentPage=nextPage;


    NSString *path;
    NSError *error;
    path = [[NSBundle mainBundle] pathForResource:[NSString stringWithFormat:@"pas%02i",nextPage+1] ofType:@"m4a"];
    if ([[NSFileManager defaultManager] fileExistsAtPath:path])
    {
        player = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL fileURLWithPath:path] error:&error];
        player.volume = 0.5f;
        [player prepareToPlay];
        [player setNumberOfLoops:0];
        [player play];
    }
    sleep(1);

    NSString *path2;
    NSError *error2;
    path2 = [[NSBundle mainBundle] pathForResource:[NSString stringWithFormat:@"passun%02i",nextPage+1] ofType:@"m4a"];
    if ([[NSFileManager defaultManager] fileExistsAtPath:path2])
    {
        player = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL fileURLWithPath:path2] error:&error2];
        player.volume = 0.5f;
        [player prepareToPlay];
        [player setNumberOfLoops:0];
        [player play];
    }

我该怎么做？