We got our daughter into the muff-style headset around the time she had been walking for some months. Prior to that we used cut-down earplugs and a baby bonnet to hold them in place. That was a bit of a challenge.
To get her used to the headset we made sure it was green like our headsets and we put her headset in her toy box where she discovered it. She was excited to have a headset like mom and dad and wore it around the house for a while. Then, when we got in the airplane, it was no problem getting her to wear it.
