How is it possible to stream audio directly from the iPhone® to hearing aids? When will this be available for other cell phone platforms?
Most cell phones on the market today incorporate Bluetooth, an open standard for digital wireless communication that operates in the 2.4 GHz band. The standard describes protocols, or rules, for the wireless communication. Devices which follow the standard can thus exchange information wirelessly. Cell phones can wirelessly transmit sound (and/or data) to other devices, like headsets, that also use Bluetooth technology. Until recently, it has not been possible to embed a Bluetooth chip into a hearing aid mainly due to power constraints. So for hearing instrument users to connect to cell phones, they have had to wear a gateway device to translate the Bluetooth signal from the phone to a digital wireless signal that was compatible with the specific hearing instrument’s wireless technology.
Apple, the manufacturer of the iPhone, prioritizes accessibility features in their devices. Thus, they developed a proprietary high quality audio streaming protocol for the iPhone, iPad® and iPod touch® that also operates in the 2.4 GHz band, but which requires much less power than traditional Bluetooth. This made it feasible to work directly with hearing aids, but obviously requires that the hearing aids themselves have digital wireless capacity in the 2.4 GHz band. The ReSound digital wireless system is based on 2.4 GHz. Therefore, it was possible to tap into the iPhone audio streaming capability by implementing the Apple proprietary communication protocol in addition to the existing ReSound one in the ReSound LiNX hearing instruments.
In this way, a power-efficient, high quality digital stereo audio experience is accessible directly from iPhone, iPad and iPod touch devices to the ReSound LiNX. In addition, users can take advantage of a direct wireless signal to both hearing instruments for phone calls, which is the proven best way to optimize hearing on the phone.1 Another helpful accessibility feature from Apple, “Live Listen”, lets the iPhone function as a remote microphone, picking up the voice or sound of interest near its source and streaming it in crystal clear quality directly to the ReSound LiNX instruments.
Since the audio streaming protocol for the iPhone is proprietary to Apple, wider availability of this type of feature relies to a large extent on other cell phone manufacturers to either develop their own protocols, or perhaps we may see an industry standard for digital wireless communication with hearing instruments. This may not be as far off as it may seem. Already today, the ReSound LiNX is a Bluetooth Smart device. This means that it can exchange data with Bluetooth Smart Ready devices via a ReSound app.
Bluetooth Smart is a “power-friendly” version of the open Bluetooth standard that has become popular particularly for monitoring devices like heart rate monitors and fitness trackers. Many cell phones on various platforms are Bluetooth Smart Ready today. In the case of the ReSound LiNX, Bluetooth Smart is what enables the ReSound Smart™ app. This app functions not only as a remote control for the hearing instruments, but also allows treble/bass adjustments. Additionally, it offers the capability to associate specific hearing instrument settings with a geographical location - called “geo-tagging” – as well as a “find my hearing aid” feature that can help locate a misplaced device. While the first ReSound Smart app is written for the iOS platform, it will also be released for the Android platform.
1. Picou EM, Ricketts TA. Comparison of wireless and acoustic hearing aid-based telephone listening strategies. Ear & Hearing. 2011; 32(2): 209-220.
© 2014 The GN ReSound Group, all rights reserved. Apple, iPhone, iPad and iPod touch are trademarks of Apple Inc, registered in the U.S. and other countries. Bluetooth is a trademark of Bluetooth SIG, Inc.