文字转化成语音

转的语音效果太生硬了，感觉不是很好！上代码吧～～
导入AVFoundation框架
引入头文件 #import
    AVSpeechSynthesizer *av = [[AVSpeechSynthesizer alloc]init];
    AVSpeechUtterance *utterance = [[AVSpeechUtterance alloc]initWithString:@"输入要转换的文字"];
    utterance.rate = AVSpeechUtteranceMinimumSpeechRate;
    [av speakUtterance:utterance];
    [utterance release];
    [av release];
简的设置了一下语速，详细看api吧～～