It is appropriate for the forklift driver to sound the horn when approaching a blind intersection.

Slow down at all intersections, and always sound the horn at blind ones.

These devices reduce jackhammer noise

by using destructive interference to cancel

the noisy sound, so he can hear your voice

clearly.

its easy sound signal

A sailing vessel operator should sound a blast on the horn when approaching a PWC head on. However, it is up to the operator of the motorized craft, in this case the PWC, to take evasive action.