It depends on your phone. The instructions will differ depending on make and model (eg: Samsung Galaxy S4 / iPhone 5S / Motorola Razor, etc). Re-ask the question with the missing information and make sure you categorise it to the correct category on this website for a quicker answer.
There are voice changers specifically for cell phones: http://www.spyville.com/cell-phone-voice-changer.html
Having a Femtocell system in the home would improve cell phone reception in the home. It could potentially give better voice quality and longer battery life as well.
Depends on what kind of cell phone it is
I have a LG cosmos cell having problem with voice command how can I set it up
to unlock your phone you use voice activation
your phone is not getting a complete connection, could be one cause, just a simple pwr cycle ( turning the phone off) can give you a fresh registratoin, can improve the quality of the call.
Some cell phone companies may not allow voices messages to be left when a number has been blocked, while other cell phone companies will allow a voice message.
A new battery will not improve your reception. The quality of calls is governed entirely by the efficiency of the radio network.
No, Its just a toy that looks like a cell phone.
Active Voice Control
how to answer a voice message on cellphone
yes there is that was a good qestion if u do not now about cell phones :)