19. At least one non-transitory computer-readable storage medium encoded with a plurality of computer-executable instructions that, when executed, perform a method for providing speech output for a speech-enabled application, the method comprising: receiving from the speech-enabled application a text input comprising a text transcription of a desired speech output; generating an audio speech output corresponding to at least a portion of the text input, the audio speech output comprising at least one portion carrying contrastive stress to contrast with at least one other portion of the audio speech output; and providing the audio speech output for the speech-enabled application; wherein the generating comprises: identifying a plurality of tokens of the text input of a same text normalization type for which a contrastive stress pattern is to be applied; identifying at least one token of the plurality of tokens to be rendered with contrastive stress; and assigning contrastive stress to be carried by at least one portion of the audio speech output corresponding to at least one portion of the at least one token of the text input; wherein the assigning comprises: identifying at least one first portion of the at least one token of the plurality of tokens that differs from at least one corresponding first portion of at least one other token of the plurality of tokens, and at least one second portion of the at least one token that does not differ from at least one corresponding second portion of the at least one other token; and assigning contrastive stress to be carried by at least one first portion of the audio speech output corresponding to the identified at least one first portion of the at least one token, but not to at least one second portion of the audio speech output corresponding to the identified at least one second portion of the at least one token.
19. At least one non-transitory computer-readable storage medium encoded with a plurality of computer-executable instructions that, when executed, perform a method for providing speech output for a speech-enabled application, the method comprising: receiving from the speech-enabled application a text input comprising a text transcription of a desired speech output; generating an audio speech output corresponding to at least a portion of the text input, the audio speech output comprising at least one portion carrying contrastive stress to contrast with at least one other portion of the audio speech output; and providing the audio speech output for the speech-enabled application; wherein the generating comprises: identifying a plurality of tokens of the text input of a same text normalization type for which a contrastive stress pattern is to be applied; identifying at least one token of the plurality of tokens to be rendered with contrastive stress; and assigning contrastive stress to be carried by at least one portion of the audio speech output corresponding to at least one portion of the at least one token of the text input; wherein the assigning comprises: identifying at least one first portion of the at least one token of the plurality of tokens that differs from at least one corresponding first portion of at least one other token of the plurality of tokens, and at least one second portion of the at least one token that does not differ from at least one corresponding second portion of the at least one other token; and assigning contrastive stress to be carried by at least one first portion of the audio speech output corresponding to the identified at least one first portion of the at least one token, but not to at least one second portion of the audio speech output corresponding to the identified at least one second portion of the at least one token. 20. The at least one non-transitory computer-readable storage medium of claim 19 , wherein the same text normalization type is selected from the group consisting of: an alphanumeric sequence type, an address type, a Boolean value type, a currency type, a date type, a digit sequence type, a fractional number type, a proper name type, a number type, an ordinal number type, a telephone number type, a flight number type, a state name type, a street name type, a street number type, a time type and a zipcode type.