I have created an e-pub file with read aloud. It's working fine when I read it on the redium and also highlighting the text while the voice reading it. But when I convert the fixed layout e-pub file into mobi format, the read aloud part is not working in the kindle viewer. Is kindle doesn't support read aloud?
MOBI/KF8 does not support the read aloud (audio/text synchronization) functionality.
For details, see Section 13 of the Kindle Publishing Guidelines: https://kindlegen.s3.amazonaws.com/AmazonKindlePublishingGuidelines.pdf
EDIT: Kindle apps support Whispersync for Voice/Immersion Reading, but only for selected titles that Kindle+Audible produce directly, and, as far as I know, there is no way for other professionals/agencies/publishers to create and sell them.