I wanted to see if Apple had fixed this yet, but apparently not. Since the iPhone 13 Apple has had a persistent issue with Bluetooth connections and even worse with hearing aids. I have had the same experience with 3 different pairs of hearing aids. They connect without any issues to other devices, but have persistent issues with maintaining a connection to hearing aids.
As I said I have had this issue starting with the iPhone 13. I am currently on my third iPhone 16 Pro, being more persistent to find the cause and a fix. I have gone through all of Apple’s articles and guides with no avail. Three different pairs of hearing aids has only shown that the problem is with the iPhone regardless of model, connectivity method, and manufacturer of the hearing aids.
Some of the hearing aids use just normal headset connectivity and some the Made for Apple. Neither have proved better than the other.
A recent discovery regarding the Made for Apple connections is that the hearing aid connection requires part of the connection uses an ultrasonic pulse/sound from the speakers on the iPhone and the hearing aids. I think this is periodic and for verifying quality of the connection.
I am still researching this so I’m not sure of the details.
The Made for Apple can use one of two connection methods, the first being M3 (the number indicating the version may be wrong) which uses the ultrasonic method described above and is the most common. If your heading aids support and have active telecoil or T-Coil there is the T4 connection method relying more on functionality of T-Coil (i won’t go into it here), but the hearing aids must have T-Coil (most don’t) and T-Coil must be active on the hearing aids. This connection method tends to stick more with a Bluetooth connection. As I said above, this is something I recently discovered and am still researching.
My suspicion is that starting with the iPhone 13 Apple changed the wireless chip was changed to one that Apple makes. This chip is responsible for WiFi and Bluetooth connections. That new chip, the firmware for it, and radios (this includes the antennas for transmission and receiving signals) isn’t robust enough to maintain Bluetooth connections, and even WiFi connections in cases. A note, most if not all mobile devices have been using what is called Low Energy Bluetooth (I have the name wrong) which “extends” battery life by using less power for Bluetooth.
Personally the only constant Bluetooth connections on my iPhone are an Apple Watch and my hearing aids. I wish I had a spectrum analyzer monitor the Bluetooth signal and strength, but the type I would use are expensive. They are also very accurate and collect information regarding environmental conditions.
Bluetooth uses the 2.4GHz radio frequency as do the WiFi b/g/n connections. This can cause interference which can cause connectivity issues. This may sound like an urban myth, but it is a true fact that pine trees “talk” on the 2.4GHz frequency. This means that they emit signals on the 2.4GHz frequency and this can affect connectivity, but it requires being surrounded by a considerable number of pine trees.
So currently my prime suspect is poor hardware lacking and adequate firmware. Sadly the more good information (fact and scientifically based) the higher the chances are that my next phone will be an Android based smart phone with known and proven wireless chips.
