Mobile call issue on iPhone 7

[JohnWerney]

When I make a call on my iPhone 7 I get interference with very loud short noises which makes conversation impossible 

how can I fix this 

[JJP2]

Have you checked that you have good coverage on Three, Smarty’s parent network ?

Another issue *may* be that the iPhone 7 is basically obsolete, as it’s no longer receiving software updates from Apple - iOS is now on iOS 16, and the latest version available for the iiPhone 7 is iOS 15.7.8.

With the release of the iPhone 15 due in September, the iPhone 7 is 8 years old, will be showing its age, and it’s battery health will likely be poor, which again won’t help with call quality. 

[JohnWerney]

I haven’t done anything yet as I very rarely ring anybody and text and email 

I know it’s not the latest phone but it suits for what I need and is cheap and cheap to run 

I am very grateful for your advice and interest and has given me some ideas. I think it may have been picking up interference from some wireless device such as room thermostat linked to the boiler 

[MSF]

@JohnWerney  Is it possible to try some other active sim in the phone ie. from a friend/family member?

This will show if the problem is down to the sim or the phone.