Apple has applied to the U.S. Patent & Trademark Office for a patent on detecting and integrating portable electronic devices and hearing aids. The application, filed August 2, 2011 and published today, describes a process in which a phone can automatically switch between standard and hearing aid compatible (HAC) modes.
As the patent describes, typical hearing aids operate in microphone mode or telecoil mode. Microphone mode is what is commonly associated with hearing aids; a microphone on the hearing aid picks up sound waves and converts them into an electrical audio signal. Telecoil (T-coil) mode detects a local magnetic field that has been modulated by the speaker of a compatible telephone handset.
These two modes have worked well for many individuals with hearing impairments, but the standard microphone mode does not work well with most mobile phones due to issues of ambient noise and many mobile phones lack of support for T-coil transmission. Phones with HAC modes are starting to become common but still rely on a user manually switching the phone between standard and HAC mode.
Apple’s patent application describes how the switch between these two modes could be made automatically based on conditions sensed by the handset, including a proximity sensor to indicate when the phone is held close to a user’s ear, and a magnetic field sensor to determine if the user has a hearing aid in T-coil mode.
In an embodiment of the invention, a portable audio device is configured to automatically select between a normal mode of operation and a hearing aid compatible mode of operation, where the latter configures the audio device with one or more changes that improve its compatibility with a hearing aid during an audio session (e.g., a phone call). The device includes a proximity sensor having an emitter and a receiver, and a magnetic field sensor. The proximity sensor is used to detect a change in distance of the device to an ear of a user. The magnetic field sensor is used to detect a change in the local magnetic field that has been caused by the device moving relative to a hearing aid that is worn by the user.
With the described process, future HAC iPhones could be passed between multiple users with and without hearing impairments and each user would be able to hear the conversation optimally without further user input.
Apple has a long history of providing accessibility features in its products, including iOS and OS X. The company also maintains a directory of resources on Apple-related accessibility issues.