5 ms·

"Their design cuts the most shrill and annoying frequencies by about 12 decibels, which all but removes them, making them 94% quieter. The team reduced the over

"Their design cuts the most shrill and annoying frequencies by about 12 decibels, which all but removes them, making them 94% quieter. The team reduced the overall leaf blower noise by about two decibels, making the machine sound 37% quieter." [1] Somewhat upsetting here... I don't have a problem with people doing things like this and students need encouragement, but we are talking about shifting from the sound of a leaf blower to the sound of a vacuum cleaner [2]... in the best case. One particular annoyance here: the sound emission must be from the end of the blower but also from its casing. I feel many products like these are cheaply designed, and the OEM could solve many of the nuisance issues with simple housing changes... or spending a few more pennies on the bearings or blades in assemblies. These are not OEM primary goals, as they are looking to save pennies in a lot of the parts in these designs. JHU should make these comments!, and also offer their designs for free given these are public orgs using mostly public dollars... if the result is such a big deal, getting manufacturers to commit to sound reduction in licensing deals would be a true result! https://audiology-web.s3.amazonaws.com/migrated/NoiseChart_Poster-%208.5x11.pdf_5399b289427535.32730330.pdf https://audiology-web.s3.amazonaws.com/migrated/NoiseChart_P... [2]

rad_gruchalski 2y ago
Try this one: STIHL BGA 86 Akku Laubbläser. It's shocking how quiet it is.
- whiplash451 2y ago
  mmm, the spec says 90dB [1] which is the sound level of a motorcycle at 25ft [2]. not amazing (at least on paper) [1] https://www.stihl.de/de/p/laubblaeser-blasgeraete-saughaecksler-akku-laubblaeser-bga-86-ap-system-109236 https://www.stihl.de/de/p/laubblaeser-blasgeraete-saughaecks... [2] https://www.chem.purdue.edu/chemsafety/Training/PPETrain/dblevels.htm https://www.chem.purdue.edu/chemsafety/Training/PPETrain/dbl...
  - mc32 2y ago
    Even gasoline powered echoes claim 87db. The battery powered Egos are quieter.
  - rad_gruchalski 2y ago
    It's not 90dB, I have one.
sokoloff 2y ago
> JHU should make these comments!, and also offer their designs for free given these are public orgs using mostly public dollars JHU is private. It seems like this research may have been sponsored by Black & Decker, also private.
- natemcintosh 2y ago
  Yes, these mechanical engineering senior design projects at JHU are all sponsored by some organization or another, and the sponsor gets to keep the end product (and in this case also patent pending). Source: did a mechanical engineering senior design project at JHU 6 years ago (though mine was less successful, haha)
  - grubbs 2y ago
    Was yours the pizza transport box for Pizza Hut? ;)
- omgJustTest 2y ago
  "Johns Hopkins researchers' success in winning federal funding—which accounted for close to 87% of its 2022 R&D expenditure—enables them to pursue projects in an array of fields, from human genetics to artificial intelligence." [1] https://hub.jhu.edu/2024/01/05/nsf-higher-education-research-spending-2022/ https://hub.jhu.edu/2024/01/05/nsf-higher-education-research... Oh yes... "private" org using public dollars is more appropriate.
  - sokoloff 2y ago
    It appears as if this specific research was funded by Black & Decker. If they couldn't get the benefits from it, it's not as if they'd pay JHU to do and make public this research, but rather that they'd do the research a different way, likely robbing the JHU students of the real-world problem-solving experience as a capstone project of their engineering curriculum. How JHU's other, unrelated research is funded doesn't seem terribly relevant to this privately-funded, patent-pending innovation.
omgJustTest 2y ago
(Also for those claiming JHU is private therefore not majorily dependent on federal funding, please read JHU website:https://hub.jhu.edu/2024/01/05/nsf-higher-education-research-spending-2022/ https://hub.jhu.edu/2024/01/05/nsf-higher-education-research...)

rad_gruchalski 2y ago

Try this one: STIHL BGA 86 Akku Laubbläser. It's shocking how quiet it is.

whiplash451 2y ago
mmm, the spec says 90dB [1] which is the sound level of a motorcycle at 25ft [2]. not amazing (at least on paper) [1] https://www.stihl.de/de/p/laubblaeser-blasgeraete-saughaecksler-akku-laubblaeser-bga-86-ap-system-109236 https://www.stihl.de/de/p/laubblaeser-blasgeraete-saughaecks... [2] https://www.chem.purdue.edu/chemsafety/Training/PPETrain/dblevels.htm https://www.chem.purdue.edu/chemsafety/Training/PPETrain/dbl...
- mc32 2y ago
  Even gasoline powered echoes claim 87db. The battery powered Egos are quieter.
- rad_gruchalski 2y ago
  It's not 90dB, I have one.

sokoloff 2y ago

> JHU should make these comments!, and also offer their designs for free given these are public orgs using mostly public dollars JHU is private. It seems like this research may have been sponsored by Black & Decker, also private.

natemcintosh 2y ago
Yes, these mechanical engineering senior design projects at JHU are all sponsored by some organization or another, and the sponsor gets to keep the end product (and in this case also patent pending). Source: did a mechanical engineering senior design project at JHU 6 years ago (though mine was less successful, haha)
- grubbs 2y ago
  Was yours the pizza transport box for Pizza Hut? ;)
omgJustTest 2y ago
"Johns Hopkins researchers' success in winning federal funding—which accounted for close to 87% of its 2022 R&D expenditure—enables them to pursue projects in an array of fields, from human genetics to artificial intelligence." [1] https://hub.jhu.edu/2024/01/05/nsf-higher-education-research-spending-2022/ https://hub.jhu.edu/2024/01/05/nsf-higher-education-research... Oh yes... "private" org using public dollars is more appropriate.
- sokoloff 2y ago
  It appears as if this specific research was funded by Black & Decker. If they couldn't get the benefits from it, it's not as if they'd pay JHU to do and make public this research, but rather that they'd do the research a different way, likely robbing the JHU students of the real-world problem-solving experience as a capstone project of their engineering curriculum. How JHU's other, unrelated research is funded doesn't seem terribly relevant to this privately-funded, patent-pending innovation.

omgJustTest 2y ago

(Also for those claiming JHU is private therefore not majorily dependent on federal funding, please read JHU website:https://hub.jhu.edu/2024/01/05/nsf-higher-education-research-spending-2022/ https://hub.jhu.edu/2024/01/05/nsf-higher-education-research...)