Hi JT5754,
welcome to the Apple (user-to-user) Community!
Re: "My voice can’t be heard when hearing aids are connected."
Am no expert in this area, yet your post to the community surely deserves some response.
Wondering if updating both the iOS Software on the iPhone, and, if possible, the firmware (or App) for the Resound Hearing Aids may help. (Note: It is always wise to back up iPhone data before updating)
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For iPhone: Apple support's online artlicle: About iOS 18 Updates - Apple Support says the newest iOS update is: "iOS 18.1.1" and "This update provides important security fixes and is recommended for all users".
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For Hearing Aid: You could check for firmware (or app) updates with your hearing professional, from within an existing app, or within the hearing-aid manual instructions,
or
with the hearing-aid manufacturer's website or Support Team:
Eg: Resound Support: https://www.resound.com/hearing-aids/apps
or
Resound Apps: https://www.resound.com/hearing-aids/apps
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✽ Checking with your cellular-provider about the issue may help improve the cellular connection
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Trouble-shooting suggestions if needed:
It is not always easy to pinpoint the cause of an issue like this, in order to solve it.
If the issue still occurs when the software is up-to-date, one of the suggestions below may help solve it.
✽ You may need to check you are not accidentally on "mute" when on a call, else people will not hear you.
Increasing the volume may also be helpful.
Apple support's article: While on a call on iPhone - Apple Support
says how to:
"Adjust the audio during a call
To change the volume, press the volume buttons on the side of iPhone. Or swipe down on the call banner,
then do any of the following:
- Mute: Tap the Mute button.
- Put the call on hold: Touch and hold the Mute button.
- Talk handsfree: Tap the Audio button, then choose an audio destination."
✽ You could check whether or not the battery is well-charged when the issue occurs.
✽ Moving to another location (inside or outside) may improve the hearing of your voice over cellular connection.
✽ When / if / your iPhone has a low cellular signal, you can try using "Wi-Fi Calling" :
ie: to make and receive calls through a Wi-Fi network: See: Make calls using Wi-Fi on iPhone - Apple Support
✽ You can check the iPhone settings:
Apple Support's article: Use hearing devices with iPhone - Apple Support explains how to:
"Adjust the settings and view the status of your hearing devices"
and to
"Turn on Hearing Aid Compatibility"
or
✽ For settings to automatically direct the audio of phone or FaceTime calls:
See: Route and automatically answer calls on iPhone - Apple Support
✽ You could check that nothing (eg: speck of wax, or dirt, or a cover) is blocking any openings, especially microphone: See: If the microphones on your iPhone aren't working - Apple Support
All the best :-)