Apple Inc filed a patent application (United States Patent Application 20130034234) on February 7 for a Apple logo
system that would automatically detect a hearing aid via the use of a proximity sensor and a magnetic field sensor, then select the appropriate hearing aid mode based on the detection system. Specifically, the proposed concept is summarized as:

“A hearing aid compatible portable electronic audio device is configured to automatically determine whether or not the device is being used by a hearing impaired user who is wearing a hearing aid, and select a mode of operation based on this determination. The device includes a proximity sensor and a magnetic field sensor. The proximity sensor is used to detect a change in distance of the device to the user’s ear. The magnetic field sensor is used to detect a change in magnetic field caused by the device moving relative to the hearing aid. The device selects between a normal audio mode of operation and a hearing aid compatible mode of operation based on both the change in detected distance and the change in detected magnetic field. Other embodiments are also described and claimed.”

Apple notes that some users will be sharing a single phone, and it is cumbersome for users to enable/disable a phone function depending on their active use of a hearing aid. The iPhone could produce sounds better suited for the hearing aid and stream the audio to the hearing aid via Bluetooth, which is already supported in Apple iOS6 and the upcoming “Made for iPhone” hearing aid accessories.

It has been known since at least mid-summer 2012 that Apple will be introducing “Made for iPhone” hearing aid accessories, and most of the major hearing aid manufacturers have acknowledged that they are or will be working to incorporate the protocols (for example, see comments by Starkey Executive VP Brandon Sawalich at the IHS Manufacturers’ Roundtable discussion in September as well as the upcoming Industry Insider interview with Sonova VP Marketing Maarten Barmentlo that will be published in the March edition of HR).

Source: Apple Insider and http://www.freepatentsonline.com