Nordic 2.4 GHz technology enables miniature hearing aid to stream audio direct from TVs and smartphones

March 07, 2012 // By Paul Buckley
Nordic Semiconductor ASA's proprietary 2.4GHz wireless technology is being employed by world-leading Danish hearing solutions company, GN ReSound, in its award-winning (2011 CES Innovations Award, Design & Engineering) ReSound Alera hearing aid product, which enables users to wirelessly stream audio from common consumer electronics (CE) devices such as TVs and smartphones.

The audio from smartphones can be transmitted via a chest-worn Bluetooth wireless technology microphone clip direct to their hearing aid(s) over a range of up to 20 meters.      

In operation, the end user simply connects their TV (e.g. via a SCART cable) or other CE device (e.g. desktop PCs, laptops, tablet computers, home cinema systems, radios) to a small audio streamer box equipped with a Nordic nRF24L01+ 2.4GHz transceiver. This then pairs with a second nRF24L01+ located in the ReSound Alera hearing aid.      

When the user wishes to watch TV they simply push a button on the back of their hearing aid or use a (cost optional) remote control to select the device's designated wireless channel (typically between 1 and 3) to immediately stream wireless audio in stereo direct from the TV to their hearing aid.      "It was extremely challenging to achieve this ease of end-user functionality, along with medical-grade [99.99%] field reliability and real-time audio performance in a hearing aid as small as [for the latest ReSound dot2 product] an adult finger nail weighing as much as a paper clip," admitted Thomas Olsgaard, VP of Hardware Platforms at GN ReSound.      

The entire ReSound Alera product range is built around a uniquely miniature 2.0 cm (length) x 1.5 cm (height) x 0.6 cm (thick) product form factor that has to embed an even smaller 1.4 cm (length) x 0.6 cm (height) x 0.4 cm (thick) electronic module housing an antenna without groundplane (due to lack of space), Bluetooth wireless technology radio, a proprietary (Nordic nRF24L01+) 2.4 GHz radio, plus an external microcontroller to perform the advanced audio signal processing (background noise cancellation and 'surround' sound processing) required in a hearing aid product marketed as being so sensitive it allows hearing-impaired users to hear, for example, snow being crushed under their footsteps, birds signing, and even the sound of falling rain.      

Olsgaard continues: "But all of this