Many of them have a doubt that how to increase the volume of mp3 ring tone for their mobile phone. This problem can be easily simplified by Audacity software.

Steps

1. Download and Install Audacity1.2.6 Software
2. File–> Open any mp3 file
3. Select the particular part of mp3 which you like it



4. Copy the selected part(Edit—>Copy) to New File(File–New)
5. Now paste the track (Edit–>Paste) to increase volume (Effect–>Equalization)



6. Move the 0 dB(decibel - used to measure sound level) Violet line towards upward direction and click preview
7. Done

Now you can see the difference in the volume . To save this file (File—>Save Project).
By this software you can change tempo etc.. even you can create a remix with audacity.
Audacity Tutorial CIS Documentation From Brown University