another random user writes "Patent 20120231838: Techniques and tools are described for controlling an audio signal of a mobile device. For example, information indicative of acceleration of the mobile device can be received and correlation between the information indicative of acceleration and exemplar whack event data can be determined. An audio signal of the mobile device can be controlled based on the correlation.
Microsoft's states that the types of audio signals that could be silenced by a whacking event include any of the following: a ringing, a ringtone, user-initiated audio, a tone, a played recording, an alarm, or the like. The audio signal could be in response to or indicate an incoming call, a message, an update, a reminder for a meeting or event, the playing of music or recording, or the like."
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