Onset

Onset may refer to:

Syllable

A syllable is a unit of organization for a sequence of speech sounds. For example, the word water is composed of two syllables: wa and ter. A syllable is typically made up of a syllable nucleus (most often a vowel) with optional initial and final margins (typically, consonants).

Syllables are often considered the phonological "building blocks" of words. They can influence the rhythm of a language, its prosody, its poetic meter and its stress patterns.

Syllabic writing began several hundred years before the first letters. The earliest recorded syllables are on tablets written around 2800 BC in the Sumerian city of Ur. This shift from pictograms to syllables has been called "the most important advance in the history of writing".

A word that consists of a single syllable (like English dog) is called a monosyllable (and is said to be monosyllabic). Similar terms include disyllable (and disyllabic) for a word of two syllables; trisyllable (and trisyllabic) for a word of three syllables; and polysyllable (and polysyllabic), which may refer either to a word of more than three syllables or to any word of more than one syllable.

Onset (audio)

Onset refers to the beginning of a musical note or other sound, in which the amplitude rises from zero to an initial peak. It is related to (but different from) the concept of a transient: all musical notes have an onset, but do not necessarily include an initial transient.

In phonetics the term is used differently - see syllable onset.

Onset detection

In signal processing, onset detection is an active research area. For example, the MIREX annual competition features an Audio Onset Detection contest.

Approaches to onset detection can operate in the time domain, frequency domain, phase domain, or complex domain, and include looking for:

Simpler techniques such as detecting increases in time-domain amplitude can typically lead to an unsatisfactorily high amount of false positives or false negatives.