Question

A hands-free device may only be used if it can be activated or deactivated with a

Answer 1

Are you talking about laws ?

In 2017 the law about using a device is only allowed if its voice operated so could it be ....

With your Voice..

Answer 2

A hands-free device may only be used if it can be activated or deactivated with a single swipe, tap or click.  

Explanation:

A device or equipment is said to be hands-free if it can be used without actually using the hands. In other words, a device that requires limited interaction of hands for input operations is known as hands-free. Some of the hands-free devices can also operate on voice commands. These devices represent a more convenient way of performing tasks and are used when multiple tasks are required the focus of an individual.

For example, while driving, it's more important than the driver focus on the road and does not engage in other activities that involve hands such as mobile phones, this problem can be compensated using a hands-free.