Introduction
We are currently implementing the speech-synthesis module from our conversational agent “Rachael Repp” in all pages so that visitors can hear the text as well as read it. The phonetic framework used by our group is partly based on Arpabet. This is a phonetic transcription code developed by the Advanced Research Projects Agency (ARPA) as a part of their Speech Understanding Project (1971-1976). It represents each phoneme (the smallest unit of sound in a language) of General American English with a distinct sequence of ASCII characters. Arpabet has been used in several speech synthesizers and it is also used in the CMU Pronouncing Dictionary.
Symbols
In Arpabet, every phoneme is represented by one or two capital letters. Digits are used as stress indicators and are placed at the end of the stressed syllabic vowel. Punctuation marks are used like in the written language, to represent intonation changes at the end of clauses and sentences. The stress values are:
Stress
| Value | Description |
|---|---|
| 0 | No stress |
| 1 | Primary stress |
| 2 | Secondary stress |
Vowels
Monophthongs
| Arpabet | IPA | Word examples |
|---|---|---|
| AO | ɔ | off (AO1 F); fall (F AO1 L); frost (F R AO1 S T) |
| AA | ɑ | father (F AA1 DH ER), cot (K AA1 T) |
| IY | i | bee (B IY1); she (SH IY1) |
| UW | u | you (Y UW1); new (N UW1); food (F UW1 D) |
| EH | ɛ | red (R EH1 D); men (M EH1 N) |
| IH | ɪ | big (B IH1 G); win (W IH1 N) |
| UH | ʊ | should (SH UH1 D), could (K UH1 D) |
| AH | ʌ | but (B AH1 T), sun (S AH1 N) |
| ə | sofa (S OW1 F AH), alone (AH L OW1 N) | |
| AE | æ | at (AE1 T); fast (F AE1 S T) |
Diphthongs
| Arpabet | IPA | Word Examples |
|---|---|---|
| EY | eɪ | say (S EY1); eight (EY1 T) |
| AY | aɪ | my (M AY1); why (W AY1); ride (R AY1 D) |
| OW | oʊ | show (SH OW1); coat (K OW1 T) |
| AW | aʊ | how (HH AW1); now (N AW1) |
| OY | ɔɪ | boy (B OY1); toy (T OY1) |
R-colored vowels
| Arpabet | IPA | Word Examples |
|---|---|---|
| ER | ɝ | her (HH ER0); bird (B ER1 D); hurt (HH ER1 T), nurse (N ER1 S) |
| ɚ | father (F AA1 DH ER); coward (K AW1 ER D) | |
| EH R | ɛr | air (EH1 R); where (W EH1 R); hair (HH EH1 R) |
| UH R | ʊr | cure (K Y UH1 R); bureau (B Y UH1 R OW0), detour (D IH0 T UH1 R) |
| AO R | ɔr | more (M AO1 R); bored (B AO1 R D); chord (K AO1 R D) |
| AA R | ɑr | large (L AA1 R JH); hard (HH AA1 R D) |
| IH R or IY R | ɪr | ear (IY1 R); near (N IH1 R) |
| AW R | aʊr | This seems to be a rarely used r-controlled vowel. In some dialects flower (F L AW1 R; in other dialects F L AW1 ER0) |
Consonants
Stops
| Arpabet | IPA | Word Examples |
|---|---|---|
| P | p | pay (P EY1) |
| B | b | buy (B AY1) |
| T | t | take (T EY1 K) |
| D | d | day (D EY1) |
| K | k | key (K IY1) |
| G | ɡ | go (G OW1) |
Affricates
| Arpabet | IPA | Word Examples |
|---|---|---|
| CH | tʃ | chair (CH EH1 R) |
| JH | dʒ | just (JH AH1 S T); gym (JH IH1 M) |
Fricatives
| Arpabet | IPA | Word Examples |
|---|---|---|
| F | f | for (F AO1 R) |
| V | v | very (V EH1 R IY0) |
| TH | θ | thanks (TH AE1 NG K S); Thursday (TH ER1 Z D EY2) |
| DH | ð | that (DH AE1 T); the (DH AH0); them (DH EH1 M) |
| S | s | say (S EY1) |
| Z | z | zoo (Z UW1) |
| SH | ʃ | show (SH OW1) |
| ZH | ʒ | measure (M EH1 ZH ER0); pleasure (P L EH1 ZH ER) |
| HH | h | house (HH AW1 S) |
Nasals
| Arpabet | IPA | Word Examples |
|---|---|---|
| M | m | man (M AE1 N) |
| N | n | no (N OW1) |
| NG | ŋ | sing (S IH1 NG) |
Liquids
| Arpabet | IPA | Word Examples |
| L | l | late (L EY1 T) |
| R | r or ɹ | run (R AH1 N) |
Semivowels
| Arpabet | IPA | Word Examples |
| Y | j | yes (Y EH1 S) |
| W | w | way (W EY1) |
| (missing) | hw or ʍ | "when" etc. in some dialects |