What are Polyphonic Ringtones?

Polyphonic ringtones are different from normal, mono ringtones in that they sound more like the music they are supposed to sound like. Polyphonic ringtones can play up to 16 different instruments at once (as opposed to mono ringtones, which can only play one) – guitars, drums, piano etc and high quality polyphonic tones can sound almost orchestral.

Polyphonic ringtones can be used not only as ringtones, but as message alerts as well as game sounds and effects. They can be downloaded via MMS (multimedia messaging) or WAP – you cannot receive or send them by text message as you could with mono tones.

Technical info:

Polyphonic ringtones are based on MIDI (Musical Instrument Digital Interface), an old standard for controlling things like synthesisers and sound cards. Some of the more recent model phones (like the Samsung SGH-T100) have actually got built-in synthesisers for even better quality sound.

Mobile devices use SP-MIDI (Scalable Polyphony), this is best suited because it has a limited number of simultaneous voices. It also stops what is known as note stealing.

Since the number of simultaneous voices is restricted by the available CPU power, there is the possibility that if the CPU is busy then polyphony levels will drop and the device could replace a currently playing note with the next one or alternatively not play the next note at all. Obviously this causes problems and can result in the music sounding completely different to what was intended.

SP-MIDI gets around this by allowing the composer of the music to set the priority of each note to be played at varying polyphony levels. Therefore, if polyphony levels drop, the most important notes will still be played and the essence of the music remains. This involves a lot more work on the part of the composer but ensures that the music will sound near enough the same across a range of devices.

In general, polyphonic ringtones range in byte size from 8K to 15K and can be downloaded over WAP or via MMS.

See also:

• What are Mono Ringtones?
• What are Java Games?
• Mobile Graphics & Animation