AHH – the Dentist Sound
/ɑː/ is a vowel sound made with the jaw open, the lips relaxed, and the tongue slightly back. It is such an open sound that your dentist will ask you to make it in order to see inside your mouth. Altogether then, open wide /ɑː/
Spellings of /ɑː/
In most spellings of /ɑː/ we’ll find the letter ‘a’ and a silent consonant ‘l’ or ‘r’; most commonly the <ar> in CAR and TART and the <al> in CALM and PALM. It’s also the <ear> in HEART, the <er> in DERBY, the <au> in AUNT, the <a> in LAGER and the <oir> in BOUDOIR.
Received Pronunciation /ɑː/ vs Regional /æ/
One of the most noticeable variations in British English accents is in words like BATH, PASS, LAUGHTER and EXAMPLE where in RP they are pronounced /ɑː/ but in many regional accents they are with /æ/, so /ˈbæθ, ˈpæs, ˈlæftə, ɪgˈzæmpl/. There is no hard and fast rule for this, but it tends to happen before certain sounds, particularly /f, s, θ/ (see trap/bath split on wikipedia).
Learners of English pronunciation should ensure that they make three different sounds in the words HEART /ˈhɑːt/, HUT /ˈhʌt/ and HAT /ˈhæt/ as many languages only have one sound in that area of the mouth. Learners should not pronounce the ‘r’ in words like CART /ˈkɑːt/ and BARK /ˈbɑːk/, unless you are aiming for American English so /ˈkɑːrt/ and /ˈbɑːrk/. The negative word AREN’T /ˈɑːnt/ is pronounced exactly the same as AUNT, your parent’s sister. Also, be very careful with the word CAN’T /ˈkɑːnt/ – as without /ɑː/ it can become the rudest word in English, can’t it?
Posh & Northern Accents
Posh English speakers say YA instead of ‘yes’. They also say CHARMING, DARLING and RATHER, rather a lot. Extremely posh speakers use /ɑː/ in words like HOUR, FLOWER, TOWER and POWER where common folk would use the combination /aʊə/ so /ˈaʊə, ˈflaʊə, ˈtaʊə, ˈpaʊə/. In Northern accents, the sound is often made towards the front, like a long [æː] so CALM, LARGE and HEART. Which sounds MARVELLOUS if you ask me.
/ɑː/is a very versatile exclamation on its own, note the different intonation in:
‘AHH that’s so cute’,
‘AHH, I didn’t know that’
It also appears with other sounds in the exclamations:
‘HAHA /ˈhɑːhɑː/, that’s really funny’,
‘HURRAH /həˈrɑː/! We’ve won!’,
‘GAH /ˈgɑː/, this is ridiculous!’,
‘BAH /ˈbɑː/, whatever.’
‘MWAH /ˈmwɑː/, kissy kissy’,
‘OOH LA LA /ˌuːlɑːˈlɑː/, very fancy’
And the sound evil pronunciation teachers make: