These maps illustrate the differing pronunciations of the three words, 'àrd', 'ceart' and 'sròn', these being

a:rt or a:rst: ceart or cearst: sro:n or stro:n, with the colon representing a long vowel.

 

These three areas are quite well defined with no overlap between the 'ceart' (no 's') area and the 'àrd',  with ('s') immediately north of it on the west coast. The 'sròn' area (without 't') includes the 'ceart' (no 't') area and extends north to Ardnamurchan and east into Perthshire.

 

In most areas, 'àrd' is pronounced with a long 'a' but in Perthshire the vowel has been replaced by the 'au' diphthong (as in 'how').  In Lewis and across the Minch in western Sutherland, the 'r' sound is not in evidence with either 'ard' or with 'ceart', while in other places e.g. Islay, the 'r' is trilled.

 

In Mull, 'sròn' is pronounced using 'th' (as in 'that') as the first consonant.  This coincides with 'th' (as in 'think'), which is also found in Mull as the first consonant in 'latha' (see 'Eigg cluck' above).