My first reaction too, but then I remembered he's only 2 1/2. He might have enough inflammation and swelling to cause a "ringing" in his ears, which often accompanies ear infections, and even just allergies. There is no real sound in the vast majority of cases, just a perception of sound.
Then again his ears might just hurt or itch very badly, and since it's a discomfort associated with his ears, he reports it as "noise". Kids often put things in strange ways.
Thank you all, SO much.