In
phonetics
Phonetics is a branch of linguistics that studies how humans produce and perceive sounds or, in the case of sign languages, the equivalent aspects of sign. Linguists who specialize in studying the physical properties of speech are phoneticians ...
, a diphone is an adjacent pair of
phones in an utterance. For example, in
aɪfəʊn the diphones are
a ɪ �f ə �ʊ �n The term is usually used to refer to a recording of the transition between two phones.
In the following diagram, a stream of phones are represented by P1, P2, etc., and the corresponding diphones are represented by D1-2, D2-3, etc.:
, P1, P2, P3, P4, P5, P6,
, D1-2=, D2-3=, D3-4=, D4-5=, D5-6=,
If the number of phones in a language is P, the theoretical number of possible diphones is P
2. However, since all languages have restrictions about what sounds can occur next to each other (see ''
phonotactics
Phonotactics (from Ancient Greek 'voice, sound' and 'having to do with arranging') is a branch of phonology that deals with restrictions in a language on the permissible combinations of phonemes. Phonotactics defines permissible syllable struc ...
''), the number of diphones in each language is usually much smaller than P
2.
Spanish has about 800 diphones and
German about 2,500.
Diphones are useful in
speech synthesis
Speech synthesis is the artificial production of human speech. A computer system used for this purpose is called a speech synthesizer, and can be implemented in software or hardware products. A text-to-speech (TTS) system converts normal langua ...
. When pre-recorded diphones are combined to create synthesized speech, the resulting sounds are much more natural than just combining simple phones. That is because the pronunciations of each phone varies based on the surrounding phones.
See also
*
Triphone
External links
The Mbrola Project
Phonetics
Phonology
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