For us, the relevant section is Section 9:2)
- A person may use a hand microphone while driving or operating a motor vehicle on a highway if
- the device is within easy reach of the driver’s seat, and
- is securely fixed to the motor vehicle or worn securely on the person’s body in a manner that does not obstruct the person’s view of the front or sides of the motor vehicle or interfere with the safety or operating equipment of the motor vehicle.
RAC also has a summary of the law in different provinces.