Are Canon pro shutters quieter than Nikons?

I shoot HS sports with a D3s, and the other guys shoot with Canons. In the burst mode, the D3s shutter release goes click, click, click, click at maybe at the rate of 11 frames/sec, while the Canon is surely quieter and it seems like its burst rate is higher than the Nikon, which I know from spec it is not. The Canon shutter goes like tick tick tick, and sounds continuously, while the D3s's sound very distinct clicks. I know we are both shooting jpg not raw.