The term 'SOUND' can be broken down into several prefixes. Phono, with 5 letters, is derived from the Greek word for SOUND and is used to describe SOUND-related technology. ULTRA, also with 5 letters, is a Latin prefix meaning beyond or above. Phon, with 4 letters, is a Greek prefix meaning voice or SOUND. Phn, with 3 letters, is a variant of phon and is also used to describe SOUND-related technology. Soni, with 4 letters, is a Latin prefix meaning SOUND. Sono, with 4 letters, is a variant of soni and is also used to describe SOUND-related technology.