Apple Patents Secondary Microphone to Automatically Control Volume
While the secondary microphone announced on the iPhone 4 was touted as being used for noise cancellation, Apple may have grander plans for the added sensor in future iPhones, iPads and other technology products. The Cupertino, California company’s patent filing suggests that the secondary microphone can intermittently scan ambient noise levels around the device so that when users are watching a movie in a loud space–like a mall–the device can automatically increase the volume and/or invoke subtitles to aid in the multimedia experience. The technology, which is similar to the light sensors in current iPhones for controlling the brightness depending on ambient light levels in the room, will automate the processor adjusting settings and make the experience simpler for the user.
According to AppleInsider, “One example accompanying the filing illustrates a video played in full screen mode on an iPhone, including an overlying and partially transparent option sheet for subtitles that can include options for color, fonts and styles for the subtitles in addition to language.”
The way the technology works, according to the Apple patent filing is:
“Thus, the mobile device can identify its local environment by sampling ambient noise present in the local environment, computing an audio fingerprint from the sampled audio noise, comparing the audio fingerprint with reference audio fingerprints stored in a database to find a match, and thus identify a type of ambient noise or environment. For example, there can be a different volume adjustment factor associated with each reference audio fingerprint. One environment may be more noisy than another environment. These differences in ambient noise would be captured by two different audio fingerprints. In a first environment (e.g., a gym), the ambient noise could be very loud and would require a large increase in volume or an invocation of subtitles. In a second environment (e.g., a shopping mall), the ambient noise could be less than the first environment and would require a lesser increase in volume and possible not an invocation of subtitles.”