Talkback: add number processing functionality

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Android is designed primarily for mobile devices, where its users deal with 
multi-digit phone numbers. Presently, text to speech engines read phone numbers 
wholely, decreasing speed, efficiency and productivity.
Example: Google TTS for example, Reads a phone number ‘9823774056’.
It is read as a whole number, with unnecessary verbosity of thousands, millions 
and billions.
It would be very convenient and quick if the above number’s digits were read 
individually, removing the verbosity of thousands, millions and billions, as 
well as paralleling the standard pronunciation of numbers.
Example: According to the above proposal, the number ‘9920’ should be 
pronounced as ‘nine nine two zero’ instead of ‘nine thousand nine hundred 
twenty’.
Some users also prefer numbers to be spoek with pairs of digits.
Example: According to the above proposal, ‘2015’ should be read as 
‘twenty fifteen’ instead of ‘two zero one five’ or ‘two thousand 
fifteen’.
A potential problem may be raised, of the implementation of the pairs of digits 
speaking functionality, whose solution is provided below.
Example: If the number has odd number of digits, such as ‘123’ which has 
three digits’. In this case, if the pairs of digits functionality is enabled, 
the first digit should be spoken separately, and the rest in pairs, that is 
‘one twenty three’.
To serve the above, some text to speech engines such as ETI Eloquence & 
Vocalizer have their own number processing options. However, text to speech 
engine specific number processing options result in duplication of number 
processing code for each different TTS. Moreover, it is more intuitive and 
ideal for a screen reader to have global number processing options, than text 
to speech engines having them specifically, in my opinion. Many text to speech 
engines do not have number processing options, such as ESpeak & Google TTS, 
where the proposed feature would be beneficial.

Original issue reported on code.google.com by [email protected] on 22 Feb 2015 at 11:03