espeak-ng/docs/phonemes.md

Phonemes

• IPA Charts
  • Consonants (Pulmonic)
  • Consonants (Non-Pulmonic)
  • Other Symbols
  • Vowels
• Features
  • Consonants
    • Voicing
    • Place of Articulation
      • Co-articulation
    • Manner of Articulation
  • Vowels
    • Height
    • Backness
    • Rounding
  • Diacritics
    • Syllabicity
    • Consonant Release
    • Phonation
    • Articulation
    • Co-articulation
      • Precomposed Characters
  • Suprasegmentals
    • Stress
    • Length
    • Rhythm
    • Intonation
  • Tones
    • Tone Stepping
  • Unused
• References

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Evan Kirshenbaum created an ASCII transcription of the International Phonetic Alphabet (IPA)^{[1], [2]}. As well as using ASCII characters for specific IPA phonemes, this transcription provides a set of 3-letter feature abbreviations allowing a phoneme to be described as a sequence of features.

This document describes the IPA phonemes using the features used by Kirshenbaum. Where Kirshenbaum does not specify a feature name, the feature name from Cainteoir Text-to-Speech^[5] is used. This is to provide a consistent naming scheme for the extended feature set. Where there is still no feature available, a custom 3-letter feature name is chosen.

The aim of the feature set described in this document is to specify the underlying phonetics and phonemics of the sounds being produced in a way that is consistent between languages and voices. While this feature set is modelled on the IPA, it is not meant to be able to preserve phoneme transcriptions when using a transcription as both the input and output phoneme sets.

This document is grouped into two sections. The first section displays the IPA charts using the feature names instead of their names, showing the IPA phoneme at that position in the chart. This makes it easier to look up the features for a given IPA phoneme.

The second section lists the features and their associated name. This section does not describe what these mean. Their meaning is described in phonetics articles, books and Wikipedia. The Wikipedia IPA^[4] article can be used as a starting point, as it links to topics and descriptions of the various phonemes.

The diacritics and suprasegmental feature lists also show their corresponding IPA symbol. This is to avoid duplicating the lists in the IPA chart and Feature sections.

IPA Charts

Consonants (Pulmonic)

	blb		lbd		dnt		alv		pla		rfx		pal		vel		uvl		phr		glt
nas		m		ɱ				n				ɳ		ɲ		ŋ		ɴ
stp	p	b					t	d			ʈ	ɖ	c	ɟ	k	ɡ	q	ɢ			ʔ
frc	ɸ	β	f	v	θ	ð	s	z	ʃ	ʒ	ʂ	ʐ	ç	ʝ	x	ɣ	χ	ʁ	ħ	ʕ	h	ɦ
apr				ʋ				ɹ				ɻ		j		ɰ
flp				ⱱ				ɾ				ɽ
trl		ʙ						r										ʀ
lat frc							ɬ	ɮ
lat apr								l				ɭ		ʎ		ʟ

Symbols to the left are vls, and to the right are vcd.

Consonants (Non-Pulmonic)

	blb	lbd	dnt	alv	pla	rfx	pal	vel	uvl	phr	glt
clk	ʘ		ǀ	ǃ			ǂ
lat clk				ǁ
vcd imp	ɓ			ɗ			ʄ	ɠ	ʛ
ejc	pʼ			tʼ		ʈʼ	cʼ	kʼ	qʼ	ʡʼ
ejc frc	fʼ		θʼ	sʼ	ʃʼ	ʂʼ		xʼ	χʼ
lat ejc frc				ɬʼ

Other Symbols

Symbol	Features
ʍ	vls lbv apr
w	vcd lbv apr
ɥ	vcd lbp apr
ʜ	vls epg frc
ʢ	vcd epg frc
ʡ	vls epg stp
ɕ	vls alp frc
ʑ	vcd alp frc
ɺ	vcd alv lat flp
ɧ	vls vzd pla frc

Vowels

	fnt		cnt		bck
hgh	i	y	ɨ	ʉ	ɯ	u
smh	ɪ	ʏ				ʊ
umd	e	ø	ɘ	ɵ	ɤ	o
mid			ə
lmd	ɛ	œ	ɜ	ɞ	ʌ	ɔ
sml	æ		ɐ
low	a	ɶ			ɑ	ɒ

Symbols to the left are unr, and to the right are rnd.

NOTE: The smh vowels are more cnt than the other vowels. However, this distinction is not needed to classify these vowels, so is not included in the above table.

Features

Consonants

Voicing

Feature	Kirshenbaum	Name
vcd	vcd	voiced
vls	vls	voiceless

Place of Articulation

Feature	Kirshenbaum	Name
blb	blb	bilabial
lbd	lbd	labio-dental
dnt	dnt	dental
alv	alv	alveolar
pla	pla	post-alveolar (palato-alveolar)
rfx	rfx	retroflex
alp		alveolo-palatal
pal	pal	palatal
vel	vel	velar
uvl	uvl	uvular
phr	phr	pharyngeal
epg		epiglottal
glt	glt	glottal

Co-articulation

Feature	Kirshenbaum	Name
lbv	lbv	labial-velar
lbp		labial-palatal

Manner of Articulation

Feature	Kirshenbaum	Name
stp	stp	plosive (stop)
nas	nas	nasal
trl	trl	trill
flp	flp	tap/flap
frc	frc	fricative
apr	apr	approximant
lat	lat	lateral
clk	clk	click
ejc	ejc	ejective
imp	imp	implosive

Vowels

Feature	Kirshenbaum	Name
vwl	vwl	vowel

Height

Feature	Kirshenbaum	Name
hgh	hgh	close (high)
smh	smh	near-close (semi-high)
umd	umd	close-mid (upper-mid)
mid	mid	mid
lmd	lmd	open-mid (lower-mid)
sml		near-open (semi-low)
low	low	open (low)

Backness

Feature	Kirshenbaum	Name
fnt	fnt	front
cnt	cnt	center
bck	bck	back

Rounding

Feature	Kirshenbaum	Name
unr	unr	unrounded
rnd	rnd	rounded

Diacritics

Syllabicity

Feature	Kirshenbaum	IPA	Name
syl	syl	◌̩	syllabic
nsy		◌̯	non-syllabic

Consonant Release

Feature	Kirshenbaum	IPA	Name
asp	asp	◌ʰ	aspirated
nrs		◌ⁿ	nasal release
lrs		◌ˡ	lateral release
unx	unx	◌̚	no audible release (unexploded)

NOTE: The nrs and lrs features are not defined in Cainteoir Text-to-Speech.

Phonation

Feature	Kirshenbaum	IPA	Name
vlv		◌̥	voiceless
vcv		◌̬	voiced
brv		◌̤	breathy voiced
crv		◌̰	creaky voiced

NOTE: The vlv and vcv diacritics may be used to fill in spaces within the IPA charts, or to make a distinction between fortis and lenis consonants. Cainteoir Text-to-Speech uses slv (slack voice) and stv (stiff voice) for these features instead.

Articulation

Feature	Kirshenbaum	IPA	Name
dzd		◌̪	dental
apc		◌̺	apical
lmn		◌̻	laminal
lgl		◌̼	linguolabial
adv		◌̟	advanced
ret		◌̠	retracted
czd		◌̈	centralized
mcz		◌̽	mid-centralized
rsd		◌̝	raised
lwr		◌̞	lowered

Co-articulation

Feature	Kirshenbaum	IPA	Name
mrd		◌̹	more rounded
lrd		◌̜	less rounded
lzd	lzd	◌ʷ	labialized or labio-velarized
pzd	pzd	◌ʲ	palatalized
vzd	vzd	◌ˠ	velarized
fzd	fzd	◌ˤ	pharyngealized
atr		◌̘	advanced tongue root
rtr		◌̙	retracted tongue root
nzd	nzd	◌̃	nasalized
rzd	rzd	◌˞	rhoticized

NOTE: The IPA supports ◌̴ for velarized or pharynealized consonants. Unicode has deprecated this combining character, while keeping the combined forms. As such, only the combined forms are supported, using the fzd feature. Cainteoir Text-to-Speech uses vfz for this combining character, but eSpeak NG does not preserve the distinction between ◌ˤ and ◌̴.

Precomposed Characters

These characters are represented as a single Unicode character. They can be used in place of the base character followed by a co-articulation combining character.

Symbol	Features
ɫ	vcd fzd alv lat apr
ɚ	unr mid cnt rzd vwl
ɝ	unr lmd cnt rzd vwl

Suprasegmentals

Stress

Feature	Kirshenbaum	IPA	Name
st1		ˈ◌	primary stress
st2		ˌ◌	secondary stress
st3		ˈˈ◌	extra stress

Length

Feature	Kirshenbaum	IPA	Name
est		◌̆	extra short
hlg		◌ˑ	half-long
lng	lng	◌ː	long

Rhythm

Feature	Kirshenbaum	IPA	Name
sbr		◌.◌	syllable break
lnk		◌‿◌	linked (no break)

Intonation

Feature	Kirshenbaum	IPA	Name
fbr		|	minor (foot) break
ibr		‖	major (intonation) break
glr		↗	global rise
glf		↘	global fall

Tones

Tone	IPA	Start	Middle	End
extra high (top)	◌˥	ts5	tm5	te5
high	◌˦	ts4	tm4	te4
mid	◌˧	ts3	tm3	te3
low	◌˨	ts2	tm2	te2
extra low (bottom)	◌˩	ts1	tm1	te1

Tone Stepping

Feature	Kirshenbaum	IPA	Name
dst		ꜛ◌	downstep
ust		ꜜ◌	upstep

Unused

Feature	Kirshenbaum	Name
	ctl	central
	mrm	murmured
	orl	oral

NOTE: The ctl and orl features are specified by Evan Kirshenbaum in Appendix A of his ASCII/IPA transcription, but are not used in the rest of the specification.

NOTE: Evan Kirshenbaum transcribes ɦ as h<?> ({mrm,glt,frc}), while Wikipedia also lists this as a {vcd,glt,frc}^[6]. This is the only phoneme that Kirshenbaum uses the mrm feature for. As such, the mrm feature is not used within this document.

References

1. Kirshenbaum, Evan, Representing IPA phonetics in ASCII (HTML). 1993.

2. Kirshenbaum, Evan, Representing IPA phonetics in ASCII (PDF). 2001.

3. International Phonetic Association, The International Phonetic Alphabet and the IPA Chart. 2015. Creative Commons Attribution-Sharealike 3.0 Unported License (CC-BY-SA).

4. Wikipedia. International Phonetic Alphabet. 2017. Creative Commons Attribution-Sharealike 3.0 Unported License (CC-BY-SA).

5. Dunn, R. H., Cainteoir Text-to-Speech Phoneme Features. 2013-2015.

6. Wikipedia. Voiced glottal fricative. 2017, Creative Commons Attribution-Sharealike 3.0 Unported License (CC-BY-SA).