Wireless, recharging features enhance hearing aids

“Right now the market is split - 75% of hearing aids are behind the ear models, and 25% are implanted into the cochlear, says Niklaus”

ON Semiconductor’s team is working towards an intelligent hearing aid which can recognise noise and adjust to them, whether that be watching television at home or having a conversation in a roomful of people.

The company has now launched two products to underline its leadership position in assisting next-gen hearing aid development – the HPM10, a PMIC; and Ezairo 7150 SL, a wireless-enabled audio processor.

Ezairo 7150 SL uses the company’s proprietary DSP technology and brings wireless connectivity to hearing aids and cochlear implants. The compact hybrid module is based on the powerful Ezairo 7100 open-programmable 24 bit mixed-signal DSP platform.

This SiP solution provides wireless multi-protocol operation and is optimised for 2.4GHz band applications, including BLE. Ezairo 7150 SL integrates EA2M, a low power 2Mb serial CMOS EEPROM used for storing hearing aid firmware and important parameters. 

To simplify and accelerate the development process of an Ezairo 7150 SL-based product, ON Semiconductor has provided a complete reference design of a Behind-The-Ear (BTE) hearing aid. The reference design includes software, hardware, and firmware which enable advanced wireless features. The control over BLE (CoBLE) function allows hearing aid users to control an array of parameters from their smartphone.

The user can adjust the hearing aid’s volume, make program changes, check the battery status, and receive phone alerts (such as incoming calls or text messages). It also features a valuable ‘Find Me’ function to help users quickly locate a misplaced hearing aid. The stereo audio streaming proprietary protocol enables music to be streamed from any external audio source (smartphones, tablet computers, televisions, etc.) through a remote dongle. The connectivity range can reach up to 10 meters in good surrounding conditions. 

The HPM10 is a PMIC that provides a high−performance solution for rechargeable batteries in hearing aids and hearing implant devices. The PMIC generates the voltage needed by the hearing aid and it also manages the charging algorithms such that the battery autonomy and the number of charging cycles are optimised. The rechargeable chemistries supported include silver−zinc, and Li−ion. HPM10 also detects zinc−air and nickel metal hydride batteries but doesn’t charge them.  

During operation, HPM10’s high efficiency power regulators help minimise lost power from the battery to the hearing aid. HPM10’s built-in Charger Communication Interface (CCIF) can pass data to the hearing aid charger during the charging process.

Battery parameters such as voltage levels, current levels, temperature and different forms of battery failures can also be communicated. Different charging parameters, representative of battery size and type, can be stored in the HPM10’s on-chip one-time programmable (OTP) memory.