This article is ratedC-class on Wikipedia'scontent assessment scale. It is of interest to the followingWikiProjects:

Physics:AcousticsMid‑importance This article is within the scope ofWikiProject Physics, a collaborative effort to improve the coverage ofPhysics on Wikipedia. If you would like to participate, please visit the project page, where you can jointhe discussion and see a list of open tasks.PhysicsWikipedia:WikiProject PhysicsTemplate:WikiProject Physicsphysics Mid This article has been rated asMid-importance on theproject's importance scale. This article is supported byAcoustics Taskforce. Technology This article is within the scope ofWikiProject Technology, a collaborative effort to improve the coverage oftechnology on Wikipedia. If you would like to participate, please visit the project page, where you can jointhe discussion and see a list of open tasks.TechnologyWikipedia:WikiProject TechnologyTemplate:WikiProject TechnologyTechnology Underwater divingLow‑importance This article is part ofWikiProject Underwater diving, an effort to create, expand, organize, and improveUnderwater diving-related articles to afeature-quality standard, and to comprehensively cover the topic with quality encyclopedic articles.Underwater divingWikipedia:WikiProject Underwater divingTemplate:WikiProject Underwater divingUnderwater diving Low This article has been rated asLow-importance on theimportance scale.

The content ofHydroacoustics wasmerged intoUnderwater acoustics on 30 December 2022. The former page'shistory now serves toprovide attribution for that content in the latter page, and it must not be deleted as long as the latter page exists. For the discussion at that location, see itstalk page.

Hello.... I think that "Underwater acoustics" and "Hydroacoustics" should be merged. It's the same thing.— Precedingunsigned comment added by94.64.189.49 (talk)14:27, 30 April 2018 (UTC)[reply]

Hello - I think that in some cases the additional sub-headings are unnecessary. I may change them - if you disagree, please respond here. Thanks,Hal peridol01:40, 24 June 2007 (UTC)[reply]

I agree with Hal. There are too many subheadings in theTheory section, especially underPropagation of sound. I also think that the definitions of the sonar equation terms (eg source level, propagation loss, target strength) don't belong hear, but undersonar.Thunderbird200:14, 30 June 2007 (UTC)[reply]

I disagree. It is impossible to understand sound propagation underwater without these defining these terms. The idea of the subheadings was to allow a particular term to be quickly found.Adresia (talk)11:26, 9 January 2008 (UTC)[reply]

Fishermen in ancient China predated Leonardo da Vinci; they listened to fish via a bamboo stick put into the water. (Source: Joseph Needham, "Science and Civilisation in China," volume 4, part 1, 1962; p. 210)Psalm 119:105 (talk)08:13, 24 April 2009 (UTC)[reply]

I have seen many versions of a plot of ambient acoustic noise in water vs. frequency. Most of them include the feature described in this article, of the thermal noise power spectral density increasing by 20 dB per decade. Can anyone find a recent experimental or theoretical treatment of this phenomenon?Jay (talk)18:16, 15 June 2011 (UTC)[reply]

See Mellen (1952) J Acoust Soc Am 24, 478-480.Dondervogel 2 (talk)18:14, 14 June 2011 (UTC)[reply]

Thanks, I found that today re-reading Wenz. I think the crux of the issue is that there are three degrees of freedom in acoustic thermal noise, but only one in electrical noise. The formula with which I am familiar W=4kTB is a special case where there is only one degree of freedom. I think Mellen is original source of this feature so I left the text alone but added a reference to the Mellen paper after "The spectral density of thermal noise increases by 20 dB per decade (approximately 6 dB per octave)."Jay (talk)18:16, 15 June 2011 (UTC)[reply]

Mention if one just sticks their head in the water to do the underwater hearing, or should their ears be protected from water getting in, etc.114.26.47.221 (talk)10:45, 12 December 2013 (UTC)[reply]

same conceptfgnievinski (talk)04:43, 6 March 2022 (UTC)[reply]

• support merge. Hydroacoustics is a synonym of underwater acoustics. No brainer.Dondervogel 2 (talk)21:42, 6 March 2022 (UTC)[reply]
• A merge with redirect does appear generally appropriate, but some of the content of hydroacousticsmay be better suited to merging into another article. Perhaps Sonar. See also a comment inTalk:Hydroacoustics#Untitled. Cheers, · · ·Peter Southwood^(talk):04:43, 25 May 2022 (UTC)[reply]

  Y Merge completedKlbrain (talk)23:53, 30 December 2022 (UTC)[reply]

• C-Class physics articles
• Mid-importance physics articles
• C-Class physics articles of Mid-importance
• C-Class acoustics articles
• Acoustics articles
• C-Class Technology articles
• WikiProject Technology articles
• C-Class Underwater diving articles
• Low-importance Underwater diving articles
• WikiProject Underwater diving articles

• Wikipedia pages using copied template
• Wikipedia pages using merged-from template without oldid
• Talk pages with comments before the first section