I don’t even know where to start with this one - we run Amazon Instant Video via a Blu-Ray player hooked up to a stereo receiver, and on some programs (mostly films, but sometimes TV shows), the sound just plain doesn’t work. Sometimes it’s all the sound, and sometimes it’s just the dialogue but not the background or intro music.
We’ve tried monkeying with the TV sound settings, the Blu-Ray sound settings, etc., but I can’t for the life of me figure out where the disconnect is. Where do we start troubleshooting?
This is almost certainly a bug (or more than one) in the TV’s software. (It’s also possible that it’s a bad encoding of the audio by Amazon, but if it’s happening on a lot of shows that is unlikely.) Find out if a software update is available from the TV’s manufacturer. If not, most likely there’s nothing you can do about it. Get an external player, like a $40 Roku stick, and connect it to your TV. (Disclaimer: I work for Roku.)