I am Samuel and I can help. Is it the volume through the earpiece (with phone up to your ear), when you have headphones on or when you use headphones?
Does it sound staticy or pork crackling when someone is talking also?
Tr this for me please:
No problem I am sorry for not being more clear. It is the small rectangle button. It is found most often at the top right of the device.
Have you downloaded anything new app wise recently?
It sounds like it is hardware related. Have you had it for less than a year?
That makes sense iphones do have some history of earpiece related issues. They also only cover them for 1 year unless you personally bought extended warranty.
I am sorry I do like my answers to have a happier outcome.
How did things turn out for you?