Problems with some calls from Samsung Infuse 4G

All:
I am having some problems calling from my Samsung Infuse 4G to some phone numbers. They are a
cousins a few miles from where I am; and, to a local recycling center. The complaints I am getting is
that I sound muffled when I am talking to them except when I raise my voice so they can hear me. Then,
their complaint is that I am too loud.
Any ideas about what their problems are and what can be done about it?

Keith Lee

All:
I found out what is causing my muffling problems with some calls. It's my Ballistic case for my
Samsung Infuse 4g. Anyone know of a cheap Otterbox case for sale for my Samsung Infuse 4g?

Keith