DRV8320: audible noise Problem

Tool/software:

I have a BLDC motor that 450W (HUB Motor for scooter). I drive it with DRV8320SRTVR smart motor driver.
I have been using 1 PWM mode and Hall effect encoder. The Hall effect sensor outputs are connected to driver directly. if Motor has no load, everythings are okey.
But if motor has load , there are much audible noise during the start motor. Motor speed is more than about 200 RPM there is no noise.
How can I solve audible noise problem.
Thank You