A cell phone is like a computer and has an operating system running behind the scenes. Use this guide to learn about Nokia Secret Cell phone codes and turn into a cell phone super user.  If you wish to unlock your Nokia Cell phone and get Nokia Unlock codes, check out our Unlock a Nokia Cell Phone article. Use the “*” button on your Nokia Cell phone to obtain the “p,w” and “+” symbols that will be used in the Cell phone Codes shown below.

Nokia Cell phone codes

1.  *3370# : This allows you to enhance the sound quality on your Nokia Cell phone. Press #3370# to deactivate Enhanced Sound Rate Code

2. *4720# : This is opposite to ESR codec activation above. Activates a lower quality sound on your Nokia Cell phone but you can gain almost 30% more in talk time. Use it if you are low on battery and need to last a business trip