I 
have a Samsung Galaxy S3 and I recently got an update from ATT. Apart 
from other things my Google Maps voice got really screwed up. It turns out that Samsung forced the settings to use its S 
Voice (sounds like a robot) instead of Google human voice (really good 
one). Any ways here's how to fix it (at least on Samsung Galaxy S3): 
Settings> My device (from top)> Language and input> Text-to-speech options > Select Google Text-to-speech Engine (By default Samsung text-to-speech engine is selected) 
Then test by listening to "Listen to an example" on the same page. Actually listen to both Google and Samsung's simulated voice.