Persuading TextToSpeech to pronounce letters of the alphabet

I'm trying to get TextToSpeech to speak alphanumeric references in the Android emulator. If I have a string such as "31NAA123", then I insert spaces between all the characters and then submit it to the speak method. It copes OK with most letters but stumbles on the 'A's, they come out as barely audible very short "ah"s, almost as short as clicks. I've tried replaceAll("A", "AY") which comes out as "ay, why". I've tried most speech rates down to 0.3f - nothing works. I'm using a UK locale to give a British accent. I'd be grateful if anyone has any usefu开发者_开发技巧l suggestions.

(I suspect 'i' will give similar problems, 'o' seems to be OK)

Have you tried inserting multiple points after the letters? Seems to work pretty well for me:

String s = "a.. b.. c.."; 

Or even slower:

String s = "a... b... c...";