Disconcertion by the defensive teams bench

[cas659]

I had a game tonight and in the first half I was administering a free throw. The defensive team was yelling and banging their chair during the free throw. I felt this was disconcertion and consulted my fellow refferee. He felt it was o.k. I'm looking for some input. I had several complaints from the stands. If nothing else I feel it was unsportsman like of the defensive team.