Hi 38Bryant,
Welcome to the Apple (user-to-user) Community.
Re: My wife just got hearing aids and she wants to have the app on her Apple Watch SE, it’s 2nd gen / 11.3.1
model MRTR3LL/A. The app is called Tru Hearing. She wants to be able to adjust the volume on her watch ….any suggestions or help, would be appreciated
Am no expert in this area, yet your request deserves some response. Seems Apple doesn't officially support the use of Hearing Aids with Apple Watch, although it does seem people are managing to use them.
Wondering if the Hearing Aid (and therefore the App) are "Made for iPhone" (Mfi) compatible:
Apple Support provides a list: List of Made for iPhone hearing devices - Apple Support
Eg: says:
TruHearing
- Flyte
- Flyte 770
- Flyte 990
- TH BTE, BTE LI
- TH Canal/ITE*, ITC/HS/ITE LI*
- TH ITE LI*
- TH RIC*
- TH RIC LI*
- TH SR LI*
If the Hearing Aids are one of the above models, seems you would be able to install the app through the iPhone.
(Side Note: Those listed with an asterisk (*) beside, are also compatible with some Mac models)
If the correct App is available through the App Store, that may be the best option.
Apple Support's online article may help:
See: Download apps on your Apple Watch - Apple Support
Eg: says:
"How to get apps
Use the iPhone that's paired with the watch, or use the App Store on the watch".
(The steps for downloading are listed in the above article)
According to the article below:
Seems using an iPhone for the download of the app for both iPhone and Watch may be necessary
Eg: Third-party (non-Apple Article: How to use your Mfi Hearing Aids with your Apple Watch
says:
"While the hearing aids show up as a Bluetooth device on your watch, you’ll need to install the companion app on your phone and watch to get all the additional features and control on your watch."
All the best :-)