You guys are so funny
My conversations with my fish are pretty limited except for " Bite me and I'll turn you into cat food!"
"You're so pretty" to my queen angel" and "do you guys really have to s#$% so much????"
Don't know that it means much to them, but they are pretty happy and healthy. Come to think of it I also ask them if they're happy, based on the fact that they all come running to the front to say hi--I guess they are. About half my stock is two years old now.
Seriously I doubt there has ever been any even remotely serrious study on the effects. I also don't think they can hear anything anyway.