The phrase '
polyphonic ringtone' is used more and more in todays
mobile phone/
cell phone jargon. Basically it's a fancy way of saying that the phone can play multiple sounds at once - producing a more pleasing sound. First generation phones contained a '
buzzer' which was only designed to produce two types of
beeps (using different
currents would produce different tones of beeps). The polyphonic design is really a cheap option for mobile phone manufacturers because it produces good sound quality without implementing more expensive circuitry to reproduce digital sound (
DSP) like the
sound card in your computer.
Polyphonic ringtones are generally
MIDI files converted to 'scalable polyphonic MIDI' files (they're optimised for the standard 4 channels supported by the phone). They can be uploaded to your phone via a
data cable or
infrared (IR) port or purchased on the web which sends it straight to your phone. See http://www.boltblue.com for an example of ringtones, pictures, etc.