Does talking to plants really affect their growth?

Not in any big way. Some say that plants like the shot of CO2 they get when we are up close and breathing on them while we are talking to them, but they get all the CO2 they need from the air anyway. The real benefit in talking to your plants comes from the fact that if you are having a conversation with you're plant, you are probable getting pretty close to it. So you can spot any signs of trouble before they get out of hand. So, the answer is really yes and no.

yes talking to plants effect their growth plants get co2 which is oxygen from the air but when u talk to them you are giving them a shot of co2

OK I say no because plants use carbon dioxide as their oxygen and let oxygen out for us to breath when we talk to the plants we are breathing on it giving it carbon dioxide which they breath on so NO it does not affect the growth it helps it so who ever say no is wrong so now you know the correct answer.