# Phonemes

- [IPA Charts](#ipa-charts)
  - [Consonants (Pulmonic)](#consonants-pulmonic)
  - [Consonants (Non-Pulmonic)](#consonants-non-pulmonic)
  - [Other Symbols](#other-symbols)
  - [Vowels](#vowels)
- [Features](#features)
  - [Consonants](#consonants)
    - [Voicing](#voicing)
    - [Place of Articulation](#place-of-articulation)
      - [Co-articulation](#co-articulation)
    - [Manner of Articulation](#manner-of-articulation)
  - [Vowels](#vowels-1)
    - [Height](#height)
    - [Backness](#backness)
    - [Rounding](#rounding)
  - [Diacritics](#diacritics)
    - [Syllabicity](#syllabicity)
    - [Consonant Release](#consonant-release)
    - [Phonation](#phonation)
    - [Articulation](#articulation)
    - [Co-articulation](#co-articulation-1)
      - [Precomposed Characters](#precomposed-characters)
  - [Suprasegmentals](#suprasegmentals)
    - [Stress](#stress)
    - [Length](#length)
    - [Rhythm](#rhythm)
    - [Intonation](#intonation)
  - [Tones](#tones)
    - [Tone Stepping](#tone-stepping)
  - [Unused](#unused)
- [References](#references)

----------

Evan Kirshenbaum created an ASCII transcription of the International Phonetic
Alphabet (IPA)<sup>\[<a href="#ref1">1</a>\], \[<a href="#ref2">2</a>\]</sup>.
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<sup>\[<a href="#ref5">5</a>\]</sup> 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<sup>\[<a href="#ref4">4</a>\]</sup>
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)

<table>
  <tr>
    <td></td>
    <th colspan="2"><code>blb</code></th>
    <th colspan="2"><code>lbd</code></th>
    <th colspan="2"><code>dnt</code></th>
    <th colspan="2"><code>alv</code></th>
    <th colspan="2"><code>pla</code></th>
    <th colspan="2"><code>rfx</code></th>
    <th colspan="2"><code>pal</code></th>
    <th colspan="2"><code>vel</code></th>
    <th colspan="2"><code>uvl</code></th>
    <th colspan="2"><code>phr</code></th>
    <th colspan="2"><code>glt</code></th>
  </tr>
  <tr>
    <th align="right"><code>nas</code></th>
    <td> </td><td>m</td>
    <td> </td><td>ɱ</td>
    <td> </td><td> </td>
    <td> </td><td>n</td>
    <td> </td><td> </td>
    <td> </td><td>ɳ</td>
    <td> </td><td>ɲ</td>
    <td> </td><td>ŋ</td>
    <td> </td><td>ɴ</td>
    <td> </td><td> </td>
    <td> </td><td> </td>
  </tr>
  <tr>
    <th align="right"><code>stp</code></th>
    <td>p</td><td>b</td>
    <td> </td><td> </td>
    <td> </td><td> </td>
    <td>t</td><td>d</td>
    <td> </td><td> </td>
    <td>ʈ</td><td>ɖ</td>
    <td>c</td><td>ɟ</td>
    <td>k</td><td>ɡ</td>
    <td>q</td><td>ɢ</td>
    <td> </td><td> </td>
    <td>ʔ</td><td> </td>
  </tr>
  <tr>
    <th align="right"><code>frc</code></th>
    <td>ɸ</td><td>β</td>
    <td>f</td><td>v</td>
    <td>θ</td><td>ð</td>
    <td>s</td><td>z</td>
    <td>ʃ</td><td>ʒ</td>
    <td>ʂ</td><td>ʐ</td>
    <td>ç</td><td>ʝ</td>
    <td>x</td><td>ɣ</td>
    <td>χ</td><td>ʁ</td>
    <td>ħ</td><td>ʕ</td>
    <td>h</td><td>ɦ</td>
  </tr>
  <tr>
    <th align="right"><code>apr</code></th>
    <td> </td><td> </td>
    <td> </td><td>ʋ</td>
    <td> </td><td> </td>
    <td> </td><td>ɹ</td>
    <td> </td><td> </td>
    <td> </td><td>ɻ</td>
    <td> </td><td>j</td>
    <td> </td><td>ɰ</td>
    <td> </td><td> </td>
    <td> </td><td> </td>
    <td> </td><td> </td>
  </tr>
  <tr>
    <th align="right"><code>flp</code></th>
    <td> </td><td> </td>
    <td> </td><td>ⱱ</td>
    <td> </td><td> </td>
    <td> </td><td>ɾ</td>
    <td> </td><td> </td>
    <td> </td><td>ɽ</td>
    <td> </td><td> </td>
    <td> </td><td> </td>
    <td> </td><td> </td>
    <td> </td><td> </td>
    <td> </td><td> </td>
  </tr>
  <tr>
    <th align="right"><code>trl</code></th>
    <td> </td><td>ʙ</td>
    <td> </td><td> </td>
    <td> </td><td> </td>
    <td> </td><td>r</td>
    <td> </td><td> </td>
    <td> </td><td> </td>
    <td> </td><td> </td>
    <td> </td><td> </td>
    <td> </td><td>ʀ</td>
    <td> </td><td> </td>
    <td> </td><td> </td>
  </tr>
  <tr>
    <th align="right"><code>lat</code>&#xA0;<code>frc</code></th>
    <td> </td><td> </td>
    <td> </td><td> </td>
    <td> </td><td> </td>
    <td>ɬ</td><td>ɮ</td>
    <td> </td><td> </td>
    <td> </td><td> </td>
    <td> </td><td> </td>
    <td> </td><td> </td>
    <td> </td><td> </td>
    <td> </td><td> </td>
    <td> </td><td> </td>
  </tr>
  <tr>
    <th align="right"><code>lat</code>&#xA0;<code>apr</code></th>
    <td> </td><td> </td>
    <td> </td><td> </td>
    <td> </td><td> </td>
    <td> </td><td>l</td>
    <td> </td><td> </td>
    <td> </td><td>ɭ</td>
    <td> </td><td>ʎ</td>
    <td> </td><td>ʟ</td>
    <td> </td><td> </td>
    <td> </td><td> </td>
    <td> </td><td> </td>
  </tr>
</table>

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

### Consonants (Non-Pulmonic)

<table>
  <tr>
    <td></td>
    <th><code>blb</code></th>
    <th><code>lbd</code></th>
    <th><code>dnt</code></th>
    <th><code>alv</code></th>
    <th><code>pla</code></th>
    <th><code>rfx</code></th>
    <th><code>pal</code></th>
    <th><code>vel</code></th>
    <th><code>uvl</code></th>
    <th><code>phr</code></th>
    <th><code>glt</code></th>
  </tr>
  <tr>
    <th align="right"><code>clk</code></th>
    <td>ʘ</td>
    <td> </td>
    <td>ǀ</td>
    <td>ǃ</td>
    <td> </td>
    <td> </td>
    <td>ǂ</td>
    <td> </td>
    <td> </td>
    <td> </td>
    <td> </td>
  </tr>
  <tr>
    <th align="right"><code>lat</code>&#xA0;<code>clk</code></th>
    <td> </td>
    <td> </td>
    <td> </td>
    <td>ǁ</td>
    <td> </td>
    <td> </td>
    <td> </td>
    <td> </td>
    <td> </td>
    <td> </td>
    <td> </td>
  </tr>
  <tr>
    <th align="right"><code>vcd</code>&#xA0;<code>imp</code></th>
    <td>ɓ</td>
    <td> </td>
    <td> </td>
    <td>ɗ</td>
    <td> </td>
    <td> </td>
    <td>ʄ</td>
    <td>ɠ</td>
    <td>ʛ</td>
    <td> </td>
    <td> </td>
  </tr>
  <tr>
    <th align="right"><code>ejc</code></th>
    <td>pʼ</td>
    <td> </td>
    <td> </td>
    <td>tʼ</td>
    <td> </td>
    <td>ʈʼ</td>
    <td>cʼ</td>
    <td>kʼ</td>
    <td>qʼ</td>
    <td>ʡʼ</td>
    <td> </td>
  </tr>
  <tr>
    <th align="right"><code>ejc</code>&#xA0;<code>frc</code></th>
    <td>fʼ</td>
    <td> </td>
    <td>θʼ</td>
    <td>sʼ</td>
    <td>ʃʼ</td>
    <td>ʂʼ</td>
    <td> </td>
    <td>xʼ</td>
    <td>χʼ</td>
    <td> </td>
    <td> </td>
  </tr>
  <tr>
    <th align="right"><code>lat</code>&#xA0;<code>ejc</code>&#xA0;<code>frc</code></th>
    <td> </td>
    <td> </td>
    <td> </td>
    <td>ɬʼ</td>
    <td> </td>
    <td> </td>
    <td> </td>
    <td> </td>
    <td> </td>
    <td> </td>
    <td> </td>
  </tr>
</table>

### 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

<table>
  <tr>
    <td></td>
    <th colspan="2"><code>fnt</code></th>
    <th colspan="2"><code>cnt</code></th>
    <th colspan="2"><code>bck</code></th>
  </tr>
  <tr>
    <th align="right"><code>hgh</code></th>
    <td>i</td><td>y</td>
    <td>ɨ</td><td>ʉ</td>
    <td>ɯ</td><td>u</td>
  </tr>
  <tr>
    <th align="right"><code>smh</code></th>
    <td>ɪ</td><td>ʏ</td>
    <td> </td><td> </td>
    <td> </td><td>ʊ</td>
  </tr>
  <tr>
    <th align="right"><code>umd</code></th>
    <td>e</td><td>ø</td>
    <td>ɘ</td><td>ɵ</td>
    <td>ɤ</td><td>o</td>
  </tr>
  <tr>
    <th align="right"><code>mid</code></th>
    <td> </td><td> </td>
    <td>ə</td><td> </td>
    <td> </td><td> </td>
  </tr>
  <tr>
    <th align="right"><code>lmd</code></th>
    <td>ɛ</td><td>œ</td>
    <td>ɜ</td><td>ɞ</td>
    <td>ʌ</td><td>ɔ</td>
  </tr>
  <tr>
    <th align="right"><code>sml</code></th>
    <td>æ</td><td> </td>
    <td>ɐ</td><td> </td>
    <td> </td><td> </td>
  </tr>
  <tr>
    <th align="right"><code>low</code></th>
    <td>a</td><td>ɶ</td>
    <td> </td><td> </td>
    <td>ɑ</td><td>ɒ</td>
  </tr>
</table>

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  |
| `vfz`   |             | ◌̴   | velarized or pharyngealized |
| `atr`   |             | ◌̘   | advanced tongue root  |
| `rtr`   |             | ◌̙   | retracted tongue root |
| `nzd`   | `nzd`       | ◌̃   | nasalized       |
| `rzd`   | `rzd`       | ◌˞  | rhoticized      |

__NOTE:__ The `fzd` and `vfz` features have the same linguistic effect. They
are used to differentiate the listed IPA diacritics.

##### 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` `vfz` `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`   |             | &#124; | 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}`<sup>\[<a href="#ref6">6</a>\]</sup>.
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. <a name="ref1"></a> Kirshenbaum, Evan,
   [Representing IPA phonetics in ASCII](http://www.kirshenbaum.net/IPA/faq.html) (HTML). 1993.

2. <a name="ref2"></a> Kirshenbaum, Evan,
   [Representing IPA phonetics in ASCII](http://www.kirshenbaum.net/IPA/ascii-ipa.pdf) (PDF). 2001.

3. <a name="ref3"></a> International Phonetic Association,
   [The International Phonetic Alphabet and the IPA Chart](https://www.internationalphoneticassociation.org/content/ipa-chart). 2015.
   Creative Commons Attribution-Sharealike 3.0 Unported License (CC-BY-SA).

4. <a name="ref4"></a> Wikipedia.
   [International Phonetic Alphabet](https://en.wikipedia.org/wiki/International_Phonetic_Alphabet). 2017.
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5. <a name="ref5"></a> Dunn, R. H.,
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