Iphone 6 makes screeching noise when pressing a button

Everytime I lock my iphone or press a letter when writing a message or unlocking it using the number/passcode it makes a horrible screeching sound! I've only had the phone from new about a month and a half and ive had trouble connecting to the internet from day one and now this problem!

The sound is exactly the same as this one on youtube https://www.youtube.com/watch?v=v0baRjA7cfs

Has anyone experienced this or can anyone shed any light on it please?

Thanks