"I like the sound of that" is a positive response to seeing something in a new way. If someone give you a new perspective, just say - I like the sound of that. It means, that rings true, or - that's how I want to see things...
It doesn't usually get said if it is not a positive situation. Once in a while you might hear it if someone is being offered a bad deal.
"I'll give you a punch in the gut if you pay a dollar."
"I don't like the sound of that."
Someone may say - I don't like the sound of that would be with music they hear and do not like. (of course)