Nokia N75

Has anyone experienced a tinny sound from the voice aid, msg reader, or voice command confirmations? I seem to have one that comes and goes. I also run a product on my phone called Mobile Speak ... I'm blind and it's a screen reader... Every so often it starts sounding bad. Comes and goes, and I haven't been able to figure out a pattern. Some of you who replaced your phone for hissing and such noises .. did you have this too?

Thanks for any and all help. I'd rather not have to exchange my phone unless necessary ... hopeing I just have some setting screwed up.....