Do old queens pip?

I hived a swarm from an old milk can into a cardboard nuc this afternoon. The swarm was hanging on the inside of the milk can, so I scooped them out with a plastic cup into the box until they started fanning and then I just sat and watched them start marching into the box.

While I was watching I heard the queen piping. It wasn't the high pitched 'pip pip pip', but more like a finger druming or a frog croaking, a deep whirling sound. I am sure that was piping but I had never read anywhere about old queens piping, do they? I would not rule out that this could be a young queen, but the question remains the same.