Open back rounded vowel · aw Low and somewhat back, with the lips rounded and protruded. Two things separate it from /ɑ/ at once: the tongue is slightly higher, and the lips must be rounded — miss either and it sounds like /ɑ/.
Three steps to /ɔ/
Low-back first, then round.
Tongue low and back
Put this drawing next to /ɑ/: both are low, but /ɔ/ is slightly higher and frontier. That difference is too small for most ears — the lips are what settles it.
Round and protrude the lips
This is the one reliable cue against /ɑ/: /ɑ/ has spread lips, /ɔ/ needs a rounded opening pushed slightly forward.
Self-check: look at your lips
Say law, then a hypothetical /lɑ/. law must be rounded. If both look the same you are producing /ɑ/ — normal in California, still a distinction in broadcasting.
Articulation (side view)
One speaker, one instant: tongue position and lip shape only. The amber circle marks what to look at; the caption says how it differs from the sound it is usually confused with.
Spelling: a, aw and ought all lead to /ɔ/
One of the least consistent vowels in English spelling — a, aw and ought all map here.
a before l is often /ɔ/: all /ɔːl/, small /smɔːl/, talk /tɔːk/. Big exception: not every a + l (shall /ʃæl/).
The most stable spelling of the lot.
ought / aught is /ɔːt/; the gh is silent here — while the gh in laugh is /f/. Same digraph, two fates.
In American English this set is drifting toward /ɑ/ as part of the cot-caught merger; regions differ a lot.
Why learners replace /ɔ/
The nearest L1 vowel is either unrounded or too high.
Read as /ɑ/ with no rounding
The most common failure: correct tongue height, spread lips, and the result is /ɑ/. law → /lɑ/.
This is the one error a mirror fixes, because rounding is visible.
Read as /oʊ/
Rounding is added but the tongue rises too far, producing a diphthong: law → /loʊ/.
Compare this drawing with the /oʊ/ page: the tongue heights are far apart.
ought / aught mispronounced
The gh is either voiced as /ɡ/ (thought → /θɔɡt/) or the whole cluster is skipped.
ought / aught is /ɔːt/ with a silent gh.
Misjudging the cot-caught merger
Many American accents (California, the Northwest) have merged /ɔ/ with /ɑ/, so cot and caught are homophones. That is an accent, not an error.
If your target is broadcasting or teaching, keep them apart — and then rounding is the only cue.
Word list
27 words grouped by where the sound sits in the word. Click a word to hear it. These are recorded as separate words, not cut out of the sentences above — a word cut from a sentence carries its neighbours' transitions and always sounds muddier. All three groups use the same speaker, so what changes between them is position, not voice.
Word-initial9
Word-medial9
Word-final9
Three groups of nine. The final group (law, paw, raw, draw, saw, straw, claw, flaw, thaw) is the tidiest: final aw is /ɔ/.
Corpus and acoustic measurements
Click any word in a sentence to play from that word. The pale band over the waveform marks the measured boundary of the target word.
Per-token data
Every number below is measured directly from the audio, not hand-annotated.
| Token | Accent | Sex | Target | Word length | ɔ duration | F0 | Pitch range | HNR |
|---|
Where the numbers come from
Every figure on this page can be recomputed from the description below.
Corpus: 12 English sentences synthesised with four American voices (two male, two female), each containing one target word, covering initial, medial and final positions. Audio is 22.05 kHz mono 64 kbps; each clip runs from 1.2 s before to 1.5 s after the target word.
Word boundaries: taken from the engine's word-level timestamps (WordBoundary) and corrected for the fixed offset between the engine timeline and the audio start (estimated per item). The target word is shaded in the waveform.
Phoneme boundaries: measured by forced alignment with the MMS_FA acoustic model. Each character's aligned frame range is kept, then a dynamic program maps the character sequence onto the phoneme sequence (th→θ, ng→ŋ, ck→k). Boundaries fall in the middle of the transition between characters; within-word coverage is 100%. Time precision is the model frame length, 20 ms, and boundaries are taken at midpoints, so effective resolution is about 10 ms.
Pitch: Praat's autocorrelation (to_pitch), 10 ms frame step, search range narrowed to the speaker's estimated range, octave errors removed. «Pitch range» is max minus min F0 within the word.
Why there are no paired differences here: this is a single-phoneme page. Eight other pages are contrast pages (θ/ð, l/r/n, vowel length) where the numbers come from paired words read by one speaker. A single-phoneme page has nothing to compare against — pairing it with a neighbour would measure that neighbour, which belongs to a different page.