While it is recommended and required to use the forklift horn in operation within the OSHA guidelines; when is excessive horn use not acceptable?

Is there such a thing? Can a forklift operator come up behind a scissor lift extended 30 ft in the air and keep sounding the horn multiple times?

OSHA recommends a couple of quick bursts of horn to let pedestrians around know there is a forklift near by, around the corner, below aerial equipment, etc.

Is it really acceptable for the forklift operator to sound his horn more than two/three times because he cant pass?

I have read some articles that excessive horn use can cause confusion and desensitization to the horn. Is this true and what else can be contributed to this argument?

What is the concensus, I am curious.