系统声音服务(System Sound Services)提供了一个接口，用于播放不超过30秒的声音。它支持的文件格式有限，具体地说只有CAF、AIF和使用PCM或IMA/ADPCM数据的WAV文件。由于这些函数没有提供操纵声音和控制音量的功能，所以当你为多媒体或者游戏创建专门的配乐时，不要使用系统声音服务。
iOS使用系统声音服务来支持三种不同的通知：
1. 声音：立刻播放一个简单的声音文件。如果手机被设置为静音，用户什么也听不到
2. 提醒：播放一个声音文件，如果手机被设置为静音或震动，将通过震动提醒用户
3. 震动：震动手机，而不考虑其他设置
在自己的工程中添加AudioToolbox.framework库，在.m文件中添加头文件：要导入AudioToolbox.h
#import <AudioToolbox/AudioToolbox.h>
系统声音服务并非是通过类实现的，而是使用传统的C语言函数调用来触发播放操作。要播放音频，需要使用的两个函数是AudioServicesCreateSystemSoundID 和 AudioServicesPlaySystemSound。还需要声明一个类型为SystemSoundID的变量，它表示要使用的声音文件。下面演示了如何加载并播放声音：
然后在需要打开声音的地方添加代码：AudioServicesPlaySystemSound(audioID);
其中audioID就是你需要打开系统声音的id号：附上系统对应提示音对照表：
/System/Library/Audio/UISounds/.
Sound ID | File name (iPhone) | File name (iPod Touch) | Category | Note |
1000 | new-mail.caf | new-mail.caf | MailReceived | |
1001 | mail-sent.caf | mail-sent.caf | MailSent | |
1002 | Voicemail.caf | Voicemail.caf | VoicemailReceived | |
1003 | ReceivedMessage.caf | ReceivedMessage.caf | SMSReceived | |
1004 | SentMessage.caf | SentMessage.caf | SMSSent | |
1005 | alarm.caf | sq_alarm.caf | CalendarAlert | |
1006 | low_power.caf | low_power.caf | LowPower | |
1007 | sms-received1.caf | sms-received1.caf | SMSReceived_Alert | |
1008 | sms-received2.caf | sms-received2.caf | SMSReceived_Alert | |
1009 | sms-received3.caf | sms-received3.caf | SMSReceived_Alert | |
1010 | sms-received4.caf | sms-received4.caf | SMSReceived_Alert | |
1011 | - | - | SMSReceived_Vibrate | |
1012 | sms-received1.caf | sms-received1.caf | SMSReceived_Alert | |
1013 | sms-received5.caf | sms-received5.caf | SMSReceived_Alert | |
1014 | sms-received6.caf | sms-received6.caf | SMSReceived_Alert | |
1015 | Voicemail.caf | Voicemail.caf | - | Available since 2.1 |
1016 | tweet_sent.caf | tweet_sent.caf | SMSSent | Available since 5.0 |
1020 | Anticipate.caf | Anticipate.caf | SMSReceived_Alert | Available since 4.2 |
1021 | Bloom.caf | Bloom.caf | SMSReceived_Alert | Available since 4.2 |
1022 | Calypso.caf | Calypso.caf | SMSReceived_Alert | Available since 4.2 |
1023 | Choo_Choo.caf | Choo_Choo.caf | SMSReceived_Alert | Available since 4.2 |
1024 | Descent.caf | Descent.caf | SMSReceived_Alert | Available since 4.2 |
1025 | Fanfare.caf | Fanfare.caf | SMSReceived_Alert | Available since 4.2 |
1026 | Ladder.caf | Ladder.caf | SMSReceived_Alert | Available since 4.2 |
1027 | Minuet.caf | Minuet.caf | SMSReceived_Alert | Available since 4.2 |
1028 | News_Flash.caf | News_Flash.caf | SMSReceived_Alert | Available since 4.2 |
1029 | Noir.caf | Noir.caf | SMSReceived_Alert | Available since 4.2 |
1030 | Sherwood_Forest.caf | Sherwood_Forest.caf | SMSReceived_Alert | Available since 4.2 |
1031 | Spell.caf | Spell.caf | SMSReceived_Alert | Available since 4.2 |
1032 | Suspense.caf | Suspense.caf | SMSReceived_Alert | Available since 4.2 |
1033 | Telegraph.caf | Telegraph.caf | SMSReceived_Alert | Available since 4.2 |
1034 | Tiptoes.caf | Tiptoes.caf | SMSReceived_Alert | Available since 4.2 |
1035 | Typewriters.caf | Typewriters.caf | SMSReceived_Alert | Available since 4.2 |
1036 | Update.caf | Update.caf | SMSReceived_Alert | Available since 4.2 |
1050 | ussd.caf | ussd.caf | USSDAlert | |
1051 | SIMToolkitCallDropped.caf | SIMToolkitCallDropped.caf | SIMToolkitTone | |
1052 | SIMToolkitGeneralBeep.caf | SIMToolkitGeneralBeep.caf | SIMToolkitTone | |
1053 | SIMToolkitNegativeACK.caf | SIMToolkitNegativeACK.caf | SIMToolkitTone | |
1054 | SIMToolkitPositiveACK.caf | SIMToolkitPositiveACK.caf | SIMToolkitTone | |
1055 | SIMToolkitSMS.caf | SIMToolkitSMS.caf | SIMToolkitTone | |
1057 | Tink.caf | Tink.caf | PINKeyPressed | |
1070 | ct-busy.caf | ct-busy.caf | AudioToneBusy | There was no category for this sound before 4.0. |
1071 | ct-congestion.caf | ct-congestion.caf | AudioToneCongestion | There was no category for this sound before 4.0. |
1072 | ct-path-ack.caf | ct-path-ack.caf | AudioTonePathAcknowledge | There was no category for this sound before 4.0. |
1073 | ct-error.caf | ct-error.caf | AudioToneError | There was no category for this sound before 4.0. |
1074 | ct-call-waiting.caf | ct-call-waiting.caf | AudioToneCallWaiting | There was no category for this sound before 4.0. |
1075 | ct-keytone2.caf | ct-keytone2.caf | AudioToneKey2 | There was no category for this sound before 4.0. |
1100 | lock.caf | sq_lock.caf | ScreenLocked | |
1101 | unlock.caf | sq_lock.caf | ScreenUnlocked | |
1102 | - | - | FailedUnlock | |
1103 | Tink.caf | sq_tock.caf | KeyPressed | |
1104 | Tock.caf | sq_tock.caf | KeyPressed | |
1105 | Tock.caf | sq_tock.caf | KeyPressed | |
1106 | beep-beep.caf | sq_beep-beep.caf | ConnectedToPower | |
1107 | RingerChanged.caf | RingerChanged.caf | RingerSwitchIndication | |
1108 | photoShutter.caf | photoShutter.caf | CameraShutter | |
1109 | shake.caf | shake.caf | ShakeToShuffle | Available since 3.0 |
1110 | jbl_begin.caf | jbl_begin.caf | JBL_Begin | Available since 3.0 |
1111 | jbl_confirm.caf | jbl_confirm.caf | JBL_Confirm | Available since 3.0 |
1112 | jbl_cancel.caf | jbl_cancel.caf | JBL_Cancel | Available since 3.0 |
1113 | begin_record.caf | begin_record.caf | BeginRecording | Available since 3.0 |
1114 | end_record.caf | end_record.caf | EndRecording | Available since 3.0 |
1115 | jbl_ambiguous.caf | jbl_ambiguous.caf | JBL_Ambiguous | Available since 3.0 |
1116 | jbl_no_match.caf | jbl_no_match.caf | JBL_NoMatch | Available since 3.0 |
1117 | begin_video_record.caf | begin_video_record.caf | BeginVideoRecording | Available since 3.0 |
1118 | end_video_record.caf | end_video_record.caf | EndVideoRecording | Available since 3.0 |
1150 | vc~invitation-accepted.caf | vc~invitation-accepted.caf | VCInvitationAccepted | Available since 4.0 |
1151 | vc~ringing.caf | vc~ringing.caf | VCRinging | Available since 4.0 |
1152 | vc~ended.caf | vc~ended.caf | VCEnded | Available since 4.0 |
1153 | ct-call-waiting.caf | ct-call-waiting.caf | VCCallWaiting | Available since 4.1 |
1154 | vc~ringing.caf | vc~ringing.caf | VCCallUpgrade | Available since 4.1 |
1200 | dtmf-0.caf | dtmf-0.caf | TouchTone | |
1201 | dtmf-1.caf | dtmf-1.caf | TouchTone | |
1202 | dtmf-2.caf | dtmf-2.caf | TouchTone | |
1203 | dtmf-3.caf | dtmf-3.caf | TouchTone | |
1204 | dtmf-4.caf | dtmf-4.caf | TouchTone | |
1205 | dtmf-5.caf | dtmf-5.caf | TouchTone | |
1206 | dtmf-6.caf | dtmf-6.caf | TouchTone | |
1207 | dtmf-7.caf | dtmf-7.caf | TouchTone | |
1208 | dtmf-8.caf | dtmf-8.caf | TouchTone | |
1209 | dtmf-9.caf | dtmf-9.caf | TouchTone | |
1210 | dtmf-star.caf | dtmf-star.caf | TouchTone | |
1211 | dtmf-pound.caf | dtmf-pound.caf | TouchTone | |
1254 | long_low_short_high.caf | long_low_short_high.caf | Headset_StartCall | |
1255 | short_double_high.caf | short_double_high.caf | Headset_Redial | |
1256 | short_low_high.caf | short_low_high.caf | Headset_AnswerCall | |
1257 | short_double_low.caf | short_double_low.caf | Headset_EndCall | |
1258 | short_double_low.caf | short_double_low.caf | Headset_CallWaitingActions | |
1259 | middle_9_short_double_low.caf | middle_9_short_double_low.caf | Headset_TransitionEnd | |
1300 | Voicemail.caf | Voicemail.caf | SystemSoundPreview | |
1301 | ReceivedMessage.caf | ReceivedMessage.caf | SystemSoundPreview | |
1302 | new-mail.caf | new-mail.caf | SystemSoundPreview | |
1303 | mail-sent.caf | mail-sent.caf | SystemSoundPreview | |
1304 | alarm.caf | sq_alarm.caf | SystemSoundPreview | |
1305 | lock.caf | sq_lock.caf | SystemSoundPreview | |
1306 | Tock.caf | sq_tock.caf | KeyPressClickPreview | The category was SystemSoundPreview before 3.2. |
1307 | sms-received1.caf | sms-received1.caf | SMSReceived_Selection | |
1308 | sms-received2.caf | sms-received2.caf | SMSReceived_Selection | |
1309 | sms-received3.caf | sms-received3.caf | SMSReceived_Selection | |
1310 | sms-received4.caf | sms-received4.caf | SMSReceived_Selection | |
1311 | - | - | SMSReceived_Vibrate | |
1312 | sms-received1.caf | sms-received1.caf | SMSReceived_Selection | |
1313 | sms-received5.caf | sms-received5.caf | SMSReceived_Selection | |
1314 | sms-received6.caf | sms-received6.caf | SMSReceived_Selection | |
1315 | Voicemail.caf | Voicemail.caf | SystemSoundPreview | Available since 2.1 |
1320 | Anticipate.caf | Anticipate.caf | SMSReceived_Selection | Available since 4.2 |
1321 | Bloom.caf | Bloom.caf | SMSReceived_Selection | Available since 4.2 |
1322 | Calypso.caf | Calypso.caf | SMSReceived_Selection | Available since 4.2 |
1323 | Choo_Choo.caf | Choo_Choo.caf | SMSReceived_Selection | Available since 4.2 |
1324 | Descent.caf | Descent.caf | SMSReceived_Selection | Available since 4.2 |
1325 | Fanfare.caf | Fanfare.caf | SMSReceived_Selection | Available since 4.2 |
1326 | Ladder.caf | Ladder.caf | SMSReceived_Selection | Available since 4.2 |
1327 | Minuet.caf | Minuet.caf | SMSReceived_Selection | Available since 4.2 |
1328 | News_Flash.caf | News_Flash.caf | SMSReceived_Selection | Available since 4.2 |
1329 | Noir.caf | Noir.caf | SMSReceived_Selection | Available since 4.2 |
1330 | Sherwood_Forest.caf | Sherwood_Forest.caf | SMSReceived_Selection | Available since 4.2 |
1331 | Spell.caf | Spell.caf | SMSReceived_Selection | Available since 4.2 |
1332 | Suspense.caf | Suspense.caf | SMSReceived_Selection | Available since 4.2 |
1333 | Telegraph.caf | Telegraph.caf | SMSReceived_Selection | Available since 4.2 |
1334 | Tiptoes.caf | Tiptoes.caf | SMSReceived_Selection | Available since 4.2 |
1335 | Typewriters.caf | Typewriters.caf | SMSReceived_Selection | Available since 4.2 |
1336 | Update.caf | Update.caf | SMSReceived_Selection | Available since 4.2 |
1350 | - | - | RingerVibeChanged | |
1351 | - | - | SilentVibeChanged | |
4095 | - | - | Vibrate | There was no category for this sound before 2.2. In the SDK this is the constant kSystemSoundID_Vibrate. |
当然你可以定义自己的提示音，打开自己工程中的音频文件，代码如下:
static SystemSoundID _ringSystemSoundID;
static void ringAudioServicesSystemSoundCompletionProc(SystemSoundID ssID, void *clientData)
{
AudioServicesPlayAlertSound(ssID);
}
void ringStartRing()
{
// 获取文件所在的路径
NSString *path = [NSString stringWithFormat:@"%@%@", [[NSBundle mainBundle] resourcePath], @"/jad0007a.wav"]; [[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategorySoloAmbient
error:nil];
//利用打开的文件创建一个soundID
AudioServicesCreateSystemSoundID((__bridge CFURLRef) path, &_ringSystemSoundID);
//当声音播放完后的回调函数，完成后将调用ringAudioServicesSystemSoundCompletionProc函数进行循环播放
AudioServicesAddSystemSoundCompletion(_ringSystemSoundID, NULL, NULL, ringAudioServicesSystemSoundCompletionProc, NULL);
//通过创建的soundID打开对应的音频文件
AudioServicesPlayAlertSound(_ringSystemSoundID);
}通过调用AudioServicesAddSystemSoundCompletion 添加可选的系统声音完成回调，通知你的程序声音已经播放完毕。如果你不使用一个接一个的短声音，那么一般可以跳过该步骤。
void ringStopRing()
{
if (_ringSystemSoundID != 0) {
//移除系统播放完成后的回调函数
AudioServicesRemoveSystemSoundCompletion(_ringSystemSoundID);
//销毁创建的SoundID
AudioServicesDisposeSystemSoundID(_ringSystemSoundID);
_ringSystemSoundID = 0;
}
}调用 AudioServicesDisposeSystemSoundID 以及相应的声音可以清除你的声音，该操作可以释放声音对象以及相关的所有资源
AudioServicesPlaySystemSound，而提醒音调用AudioServicesPlayAlertSound。
震动更容易实现，只需要调用AudioServicesPlaySystemSound，并将常量kSystemSoundID_Vibrate传递给它：
AudioServicesPlaySystemSound(kSystemSoundID_Vibrate);
如果视图震动不支持震动的设备(如iPad2)，将静默失败。因此将震动代码留在应用程序中不会有任何害处，而不管目标设备是什么。
AVAudioPlayer和SystemSoundService。这两种功能在一定程度上都适合作为游戏音效的播放方式。而两者也各有其优缺点。下面我们来总结一下有哪些：
1）AVAudioPlayer的优点
（1）可以播放任意长度音乐；
（2）可以循环播放；
（3）可以控制播放的时间；
（4）可以控制声道的音量实现立体声效果；
（5）可以调整音量。
2）AVAudioPlayer的缺点
（1）播放之前必须先加载，不能立即播放；
（2）一次一个AudioPlayer只能播放所加载的音乐，不能同时播放好几次同样的音乐。
（3）没有振动效果
3）SystemSoundService的优点：
（1）能够立即播放
（2）能够在同一时间播放多次音乐
（3）可以加上振动效果
4）SystemSoundService的缺点：
（1）不能循环播放
（2）不能控制播放时间
（3）不能控制声道
（4）不能控制音量
（5）不能暂停音乐
因此，我们可以考虑综合两者的功能！
