Thursday 25 February 2021

Iphone 12 hearing aid compatibility problem

iPhone 12 bluetooth hearing aid compatibility issue (and a "works-for-me" solution)

More on that issue, including audio samples shortly on my YouTube channel.

No problems with iPhone 8

I had an iPhone 8 for the last 3 or so years, and just by the end of last year, I upgraded my hearing aid to the latest&greatest Li-Ion powered bluetooth connected version I could get my hands on.

Specs & hearing aid - no problem.
Things become tricky with a mask.

Apart from better hearing, the additional bonus of having a top quality, hands-free, near invisible headset for the numerous audio and video conferences that came with the pandemic was just a blast.

Until I switched to an iPhone 12.

The hearing aid

It seems that there is only a small number of actual manufacturers and a lot of brand names hearing aids are sold under. Mine are sold as SoniTon UP5 R Li with a CE 0543 mark that indicates it has been certified as a medical device in Denmark.

The actual manufacturer seems so be Unitron Hearing Ltd. in Canada. Other names/brands the device is sold under are: Vista DX 350 R Li, AudioNova DX 30 R Li, DX Moxi Move R 3, scala DX 350 R Li, excellence 2 V2 R Li

It is not specifically "made for iPhone", but can be used universally, so while the use as headset/headphones is generic, control is via Bluetooth LE and a "hearing remote" app.

The "hearing remote" app allows control via the iPhone

iPhone 12 problems

At first I didn't notice anything wrong. Podcasts and music were fine to listen to. But callers and team-mates complained about choppy, scratchy audio. Same thing on my side: distorted audio.

I went investigating and found that to be a common problem for people using the iPhone 12 series (mini, pro and "regular" alike). Even for hearing aids specifically "Made for iPhone. The sterotypical recommendation to use the latest iOS version as found on Apple's support and discussion pages were useless for me. Apple claims to have it solved for "Made for iPhone" with iOS 14.2.1, which left me on my own.

The solution

It appears, that the problem lies with "Adaptive Bluetooth". I am not sure which flavour of "Adaptive Bluetooth" that is, since both "adaptive frequency hopping" and "adaptive codec selection" (Qualcomm aptX Adaptive) are "adaptive". If you know, please leave a note in the comments.

Disable Adaptive Bluetooth
Adaptive bluetooth can be disabled in the "remote hearing" app. The hearing aids have to be restarted after changing that setting.

With this setting changed, calls, voice recordings and video conferences are ok again. I am not quite sure whether or not I sense a very slightly reduced audio quality for music since then. If so, the codec chosen for compatibility might not be the best for music.