Pleo's just a juvenile, trying hard to figure out what in his environment is important for him to pay attention to. Should he focus on avoiding a table edge or listen to you calling him?
Pleo hears best in a quiet room when you talk to him from the left or the right from not too far away. Steady sound gets his attention: Pleo will ignore short bursts of sound like claps or short "Pleo" calls—otherwise his head would be spinning all the time! Just keep on talking!
Next: Making friends