{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,13]],"date-time":"2026-10-13T15:56:05Z","timestamp":1791906965828,"version":"4.3.4"},"reference-count":17,"publisher":"Acoustical Society of America (ASA)","issue":"3","content-domain":{"domain":["pubs.aip.org"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[2011,9,1]]},"abstract":"<jats:p>The prevalence of noise in the riding of motorcycles has been a source of concern to both riders and researchers in recent times. Detailed flow field information will allow insight into the flow mechanisms responsible for the production of sound within motorcycle helmets. Flow field surveys of this nature are not found in the available literature which has tended to focus on sound pressure levels at ear as these are of interest for noise exposure legislation. A detailed flow survey of a commercial motorcycle helmet has been carried out in combination with surface pressure measurements and at ear acoustics. Three potential noise source regions are investigated, namely, the helmet wake, the surface boundary layer and the cavity under the helmet at the chin bar. Extensive information is provided on the structure of the helmet wake including its frequency content. While the wake and boundary layer flows showed negligible contributions to at-ear sound the cavity region around the chin bar was identified as a key noise source. The contribution of the cavity region was investigated as a function of flow speed and helmet angle both of which are shown to be key factors governing the sound produced by this region.<\/jats:p>","DOI":"10.1121\/1.3621097","type":"journal-article","created":{"date-parts":[[2011,9,3]],"date-time":"2011-09-03T22:09:31Z","timestamp":1315087771000},"page":"1164-1172","update-policy":"https:\/\/doi.org\/10.1063\/aip-crossmark-policy-page","source":"Crossref","is-referenced-by-count":12,"title":["Aeroacoustic sources of motorcycle helmet noise"],"prefix":"10.1121","volume":"130","author":[{"given":"J.","family":"Kennedy","sequence":"first","affiliation":[{"name":"University of Bath Department of Mechanical Engineering, , Bath, BA2 7AY, United Kingdom"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"O.","family":"Adetifa","sequence":"additional","affiliation":[{"name":"University of Bath Department of Mechanical Engineering, , Bath, BA2 7AY, United Kingdom"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"M.","family":"Carley","sequence":"additional","affiliation":[{"name":"University of Bath Department of Mechanical Engineering, , Bath, BA2 7AY, United Kingdom"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"N.","family":"Holt","sequence":"additional","affiliation":[{"name":"Bath Spa University School of Science, Society and Management, , Newton Park, Newton Street Loe, Bath, BA2 9BN, United Kingdom"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"I.","family":"Walker","sequence":"additional","affiliation":[{"name":"University of Bath Department of Psychology, , Bath, BA2 7AY, United Kingdom"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"231","published-online":{"date-parts":[[2011,9,2]]},"reference":[{"key":"2023080109032073600_c1","volume-title":"\u201cResearch into the noise hazard and loss of hearing in motorcycle patrols of the state police,\u201d","year":"1989"},{"key":"2023080109032073600_c2","volume-title":"\u201cPractical research into application possibilities of otoplastics with motorcycle patrols of the state police,\u201d","year":"1990"},{"key":"2023080109032073600_c3","volume-title":"\u201cComparative sound measurements with alternative motorcycles, fairings and helmets on behalf of the state police,\u201d","year":"1990"},{"key":"2023080109032073600_c4","volume-title":"\u201cComparative research into the noise hazard to motorcyclists with various fairings, shields and helmets,\u201d","year":"1990"},{"key":"2023080109032073600_c5","first-page":"319","article-title":"\u201cSources and levels of noise under motorcyclists\u2019 helmets\u201d","volume":"16","year":"1994","journal-title":"Proc. Inst. Acoust."},{"key":"2023080109032073600_c6","first-page":"979","article-title":"\u201cNoise levels and noise reduction under motorcycle helmets,\u201d","volume-title":"Proceedings of Internoise","year":"1996"},{"key":"2023080109032073600_c7","first-page":"70","article-title":"\u201cNoise induced hearing loss in occupational motorcyclists,\u201d","volume":"3","year":"2004","journal-title":"J. Environ. Health Res."},{"key":"2023080109032073600_c8","first-page":"18","article-title":"\u201cShock reason why we need quieter lids,\u201d","volume-title":"Bike","year":"2007"},{"key":"2023080109032073600_c9","doi-asserted-by":"publisher","first-page":"187","DOI":"10.1017\/S0022112078000580","article-title":"\u201cVisual observations of the flow past a sphere at Reynolds numbers between 104 and 106,\u201d","volume":"85","year":"1978","journal-title":"J. Fluid Mech."},{"key":"2023080109032073600_c10","doi-asserted-by":"publisher","first-page":"565","DOI":"10.1017\/S0022112072000874","article-title":"\u201cExperiments on the flow past spheres at very high Reynolds numbers,\u201d","volume":"54","year":"1972","journal-title":"J. Fluid Mech."},{"key":"2023080109032073600_c11","doi-asserted-by":"publisher","first-page":"209","DOI":"10.1017\/S0022112074000644","article-title":"\u201cVortex shedding from spheres,\u201d","volume":"62","year":"1974","journal-title":"J. Fluid Mech."},{"key":"2023080109032073600_c12","doi-asserted-by":"publisher","first-page":"2652","DOI":"10.1121\/1.3588847","article-title":"\u201cThe effects of windscreen flow on noise in motorcycle helmets,\u201d","volume":"129","year":"2011","journal-title":"J. Acoust. Soc. Am."},{"key":"2023080109032073600_c13","doi-asserted-by":"publisher","first-page":"040002","DOI":"10.1121\/1.3602214","article-title":"\u201cThe experimental measurement of motorcycle noise\u201d","volume":"12","year":"2011","journal-title":"Proc. Meet. Acoust."},{"key":"2023080109032073600_c14","doi-asserted-by":"publisher","first-page":"040005","DOI":"10.1121\/1.3431693","article-title":"\u201cNoise mechanisms in motorcycle helmet noise,\u201d","volume":"9","year":"2010","journal-title":"Proc. Meet. Acoust."},{"key":"2023080109032073600_c15","article-title":"\u201cAnthropometry and biomechanics,\u201d","volume-title":"Man- Systems Integration Standards: Volume I","year":"1995"},{"key":"2023080109032073600_c16","doi-asserted-by":"publisher","first-page":"31","DOI":"10.1006\/jsvi.2000.3101","article-title":"\u201cSpectral conditioning of propeller noise from broadband sources\u201d","volume":"238","year":"2000","journal-title":"J. Sound Vib."},{"key":"2023080109032073600_c17","doi-asserted-by":"publisher","first-page":"225","DOI":"10.1243\/PIME_PROC_1992_206_123_02","article-title":"\u201cReduced order modelling of non-linear squeeze film dynamics,\u201d","volume":"206","year":"1992","journal-title":"Proc. IMechE"}],"container-title":["The Journal of the Acoustical Society of America"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pubs.aip.org\/asa\/jasa\/article-pdf\/130\/3\/1164\/15296132\/1164_1_online.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/pubs.aip.org\/asa\/jasa\/article-pdf\/130\/3\/1164\/15296132\/1164_1_online.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,8,1]],"date-time":"2023-08-01T09:05:31Z","timestamp":1690880731000},"score":1,"resource":{"primary":{"URL":"https:\/\/pubs.aip.org\/jasa\/article\/130\/3\/1164\/912058\/Aeroacoustic-sources-of-motorcycle-helmet-noise"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2011,9,1]]},"references-count":17,"journal-issue":{"issue":"3","published-print":{"date-parts":[[2011,9,1]]}},"URL":"https:\/\/doi.org\/10.1121\/1.3621097","relation":{},"ISSN":["0001-4966","1520-8524"],"issn-type":[{"value":"0001-4966","type":"print"},{"value":"1520-8524","type":"electronic"}],"subject":[],"published-other":{"date-parts":[[2011,9]]},"published":{"date-parts":[[2011,9,1]]}}}