A new patent from Apple suggests that touch sensors, like those in the iPhone’s touchscreen, can improve sound quality during a call. The sensors would help to automatically boost or lower the speaker volume depending on how closely the phone is clamped to the ear.
In a US patent filed today, Apple engineer Shaohi Chen proposes using an array of capacitive touch sensors “dispersed around the earpiece region” of a phone to take a touch-sensed “imprint” of the user’s ear.
That picture is then compared with standard earprints – previously determined in lab tests on a wide range of people – to work out how far from the user’s eardrum the earpiece is.
Comparison made, the information is used to boost or reduce the volume of the sound produced by the in-phone audio processing circuit – also taking into account the level of background noise entering the phone’s mic. “This compensates for acoustic leakage between the user’s ear and the earpiece,” Chen writes in the patent.
Apple touchscreen phones already have a simple touch sensor near the earpiece to disable the phone’s on-screen keypad when the device is pressed against the head – although problems with this proximity sensor have been reported by some users of the iPhone 4, released earlier this year. Chen says his idea would simply need an array of such sensors arranged in grids so that earprints can be defined as a set of coordinates.