speaker greyed out on iphone7plus

iPhone Volume and Receiver

Turn up the volume

• While you're on a call, adjust the volume with the volume buttons. Make sure that you can see the volume indicator on the screen when you press the volume buttons.
• From our experience with iPhones, we have seen that many issues can be traced back to your iPhone accessories.

1. The first thing to try is to remove your iPhone’s cover/case and see if the muffled sound issue on your iPhone goes away.
2. This issue with iPhone covers is even more critical if you are using an iPhone case that flips.
3. Sometimes, when you try to flip the cover to the back while on a call, it can block the rear microphone thereby interfering with the call volume and quality on your iPhone.

• If you bought the Apple Folio cover for your iPhone X Series or iPhone 8, remove the cover and give it a try.

• Since your iPhone is new/’er’, the chances are that the microphones are not covered with any debris or dirt. It still may be a good idea to check and make sure that the microphone positions on your device are relatively clean.

• If using wired earbuds or headsets, clean the lightning port where they attach to your iPhone

Apple consistently releases iOS updates.

• If you have not yet updated your iPhone, update your device to this latest iOS and see if the issue is resolved.

Apple’s iOS upgrades include bug fixes and performance improvements.

• A few folks found some relief by trying out a workaround that pertains to noise canceling on your iPhone.

1. Tap on Settings > General > Accessibility> Phone Noise Cancellation.
2. Switch this setting to OFF.
3. This change does work for many folks, but we don’t think that this is a sustainable workaround. It defeats one of the good features on your iPhone.

• A reader found some relief by changing the Cellular settings on his device.

1. If you have LTE, Tap on Settings > Cellular > Cellular Data Options > Enable LTE.
2. Here change it from ‘Voice & Data’ to Data Only.

• Are you by any chance using any third party call blocking/filtering app on your iPhone?

1. Try and uninstall the Phone related third-party apps and see if it resolves your call sound issue.
2. This problem is rare, but we have seen at times when third-party apps or extensions can interfere with the iPhone experience especially after iOS upgrades.

• There is no harm trying out the Reset Network Settings.

1. When your issue is related to networks, try this reset. Tap on Settings > General > Reset > Reset Network Settings.
2. Once the iPhone starts back up, you should also check and see if any pending carrier updates needed on your iPhone.
3. Tap on Settings > General > About your phone…and carrier.

• Sometimes when the problem is carrier related, your particular carrier usually offers better guidance on how to address the sound issues. This tip might just save you a trip to the Apple store.

If you can't hear a person on a call or voicemail or if the sound isn't ...

https://support.apple.com/en-in/HT203800

I have a passion and hobby to go through complete literature and review of all iOS and needless to say I haven't missed iOS 12.1.3 & 12.1.4 assessment published on various news media and on Apple web page including leading news magazines (Forbes).

No where I could find any link on the problem of "Unable to hear" faced by you. Introspect and have a complete and thorough check on the way you handle settings on your iPhone.

Read often for a peaceful life.

its an IC problem

Here's the fix , it worked for me

http://www.fixstop.com/blog/iphone-7-speaker-grayed-out-and-microphone-not-working-solution/