Users switch their devices to silent when they want to:
Avoid being interrupted by unexpected sounds, such as phone ringtones and incoming message sounds
Avoid hearing sounds that are the byproducts of user actions, such as keyboard or other feedback sounds, incidental sounds, or app startup sounds
Avoid hearing game sounds that are not essential to using the game, such as incidental sounds and soundtracks
The Ring/Silent (or Silent) switch does not silence sounds that result from user actions that are solely and explicitly intended to produce sound. For example:
Media playback in a media-only app is not silenced because the media playback was explicitly requested by the user.
A Clock alarm is not silenced because the alarm was explicitly set by the user.
A sound clip in a language-learning app is not silenced because the user took explicit action to hear it.
Conversation in an audio chat app is not silenced because the user started the app for the sole purpose of having an audio chat.
http://developer.apple.com/library/ios/#documentation/userexperience/conceptual/mobilehig/TechnologyUsage/TechnologyUsage.html如果游戏在静音模式下发出声音按理不应该上架的……