A good starting point for feeling the oral posture of this accent is to make the shape of the vowel /ɒ/, and then simply breathe in and out through that space. Imagine holding that little round space of air towards the front of your mouth and shift it slightly with your tongue, as though it were a mouthful of hot soup that you were cooling by blowing air past it. The combination of lip protrusion, cupping of the front of the tongue and raising of the middle of the tongue towards rear of the palate – these are comfortable positions for a speaker of this accent. As you begin to experiment with the sounds of the accent you’ll find that the tongue may feel like it spreads inside the mouth since there are fewer /r/ sounds drawing the sides of the tongue toward its center line. In addition, the velum can hang low, allowing sound to travel out through the nose.
This oral posture can be seen as the cause of the characteristic sounds of the accent or as the result, but it is at least a useful way for an actor to keep in contact with the accent throughout the performance. Many interesting and subtle sounds that I haven’t taken the time to describe, can be achieved by maintaining this configuration of articulators.
LOT = CLOTH = THOUGHT [lɒt] [klɒθ] [θɒt]
Depending on where you grew up, you may perceive the words LOT, CLOTH, and THOUGHT as having the same vowel, or you may think of two of the three being pronounced one way and the third as slightly different. In London, you’re likely to hear LOT and CLOTH as sharing the vowel [ɒ], but THOUGHT pronounced with [ɔː]. New York splits these word groups differently, pronouncing LOT as [ɑ] but CLOTH and THOUGHT as [ɔə̆] . In California, it’s quite common to pronounce all three with the same vowel [ɑ]. Boston also merges these three categories into one, but the sound for each word is [ɒ]. As you listen to samples you’ll find that there is stil some variation – variation between speakers, and variation for a single speaker from one word to another – but the vowels in the words in all three categories cluster around [ɒ].