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.


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:


Value Description
0 No stress
1 Primary stress
2 Secondary stress



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)


Arpabet IPA Word Examples
EY say (S EY1); eight (EY1 T)
AY my (M AY1); why (W AY1); ride (R AY1 D)
OW show (SH OW1); coat (K OW1 T)
AW 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)



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)


Arpabet IPA Word Examples
CH chair (CH EH1 R)
JH just (JH AH1 S T); gym (JH IH1 M)


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)


Arpabet IPA Word Examples
M m man (M AE1 N)
N n no (N OW1)
NG ŋ sing (S IH1 NG)


Arpabet IPA Word Examples
L l late (L EY1 T)
R r or ɹ run (R AH1 N)


Arpabet IPA Word Examples
Y j yes (Y EH1 S)
W w way (W EY1)
(missing) hw or ʍ "when" etc. in some dialects