Male canary singing very loudly and very frequently, any solutions?

I recently got a male canary that sings very loudly, to the point that I think it's hurting my ears. On top of that, he is a frequent singer, singing every 3 minutes or so. When I let him free-fly he sings less frequently (about once every 10'), but once he's back in his cage it's back at the 3' mark.

I supply him with plenty of different foods like apple, lettuce, millet, seed sticks, egg food etc. to keep him busy but it doesn't make a difference.

How can I make him sing less frequently and sing more quiet songs? It doesn't have to be toned down a lot, just enough that it's not hurting my ears.

Edit: I managed to find some time to measure his songs. I did 3 measurements and it ranged from 110 to 115 dB, which can very well damage the ears of humans. I've also read that the average canary's song is only around 60-70 dB