issue call sony z3 help

[OmarCuba]

I can't listen well the voice of the caller, it's distorsed and sometimes the call Just finishes without ringing off

[Uliwooly]

Does your phone has a protective case or film?

[Phy]

Has your phone been exposed to water?

[OmarCuba]

It has glass screen protector and a case

[OmarCuba]

I don't expose it to water

[Uliwooly]

Remove both and check again

[OmarCuba]

Why do you think it happens cause the speaker doesn't seem to be hiding it and it's really dificult to do remove it doesn't cost me cheap u.u
The only reason i could remove it is if i'm sure about doing it