i’m not educated in the field specifically, but what i do have a knowledge base of is the fact that this probably isn’t a technical W for the leaf blower industry, especially judging that most commercial leaf blowers are gas ICE based equipment, and that even with the home market being more accessible than ever, a lot of home owners still use ICE based equipment.

Put together with the fact that the high pitch whine attenuates aggressively at distance, compared to much lower pitches. It’s likely that it has little benefit for anybody other than the user, in which case, hearing protection.

I’m sure this is a more broad accomplishment, but this has been a field of study across multiple industries for multiple reasons.