In geography, a sound is a large sea or ocean inlet larger than a bay, deeper than a bight, and wider than a fjord; or a narrow sea or ocean channel between two bodies of land (see also strait).
There is little consistency in the use of "sound" in English-language place names.
A sound is often formed by the sea's flooding a river valley. This produces a long inlet where the sloping valley hillsides descend to sea-level and continue beneath the water to form a sloping sea floor. The Marlborough Sounds in New Zealand are a good example of this type of formation.
Sometimes a sound is produced by a glacier's carving out a valley on a coast then receding, or the sea's invading a glacier valley. The glacier produces a sound that often has steep, near vertical sides that extend deep under water. The sea floor is often flat and deeper at the landward end than the seaward end, due to glacial moraine deposits. This type of sound is more properly termed a fjord (or fiord). The sounds in Fiordland, New Zealand, have been formed this way.
A sound generally connotes a protected anchorage.
In the more general northern European usage, a sound is a strait or the most narrow part of a strait. In Scandinavia and around the Baltic Sea, there are more than a hundred straits named Sund, mostly named for the island they separate from the continent or a larger island.
In contrast, the Sound is the internationally recognized, short name for the Øresund, the narrow stretch of water that separates Denmark and Sweden, and is the main waterway between the Baltic Sea and the North Sea. It is also a colloquial short name, among others, for Plymouth Sound, England.
In areas explored by the British in the late 18th Century, particularly the northwest coast of North America, the term "sound" was applied to inlets containing large islands, such as Howe Sound in Vancouver and Puget Sound in Washington State. It was also applied to bodies of open water not fully open to the ocean, such as Caamaño Sound or Queen Charlotte Sound in Canada, or broadenings or mergings at the openings of inlets, like Cross Sound in Alaska and Fitz Hugh Sound in British Columbia.
In the United States, Long Island Sound separates Long Island from the eastern shores of the Bronx, Westchester County, and southern Connecticut, but on the Atlantic Ocean side of Long Island, the body of water between Long Island and its barrier beaches is termed the Great South Bay. Pamlico Sound is a similar lagoon that lies between North Carolina and its barrier beaches, the Outer Banks, in a similar situation. The Mississippi Sound separates the Gulf of Mexico from the mainland, along much of the gulf coasts of Alabama and Mississippi. On the West Coast, Puget Sound, by contrast, is a deep arm of the ocean.
The term sound is derived from the Anglo-Saxon or Old Norse word sund, which also means "swimming".
The word sund is already documented in Old Norse and Old English as meaning "gap" (or "narrow access"). This suggests a relation to verbs meaning "to separate", such as absondern and aussondern (German), söndra (Swedish), sondre (Norwegian), as well as the English noun sin, German Sünde ("apart from God's law"), and Swedish synd. English has also the adjective "asunder" and the noun "sundry', and Swedish has the adjective sönder ("broken").
In Swedish and in both Norwegian languages, "sund" is the general term for any strait. In Swedish and Nynorsk, it is even part of names worldwide, such as in Swedish "Berings sund" and "Gibraltar sund", and in Nynorsk "Beringsundet" and "Gibraltarsundet".
Broad Sound near Clairview, QueenslandCamden Sound at Kuri Bay, Western AustraliaCockburn Sound, Western AustraliaDenham Sound, part of Shark Bay in Western AustraliaKing George Sound at Albany, Western AustraliaKing Sound at Derby, Western AustraliaMontague Sound, near Bigge Island, Western AustraliaNoosa Sound, Noosa, QueenslandYork Sound, Western AustraliaExuma Sound, bordered by Eleuthera, Cat Island and Great Exuma, among othersMillars Sound, New ProvidenceNorth Sound, BiminiRock Sound, EleutheraGreat Sound, towards the island's northwest endHarrington Sound, towards the northeast endLittle Sound, part of Great SoundBritish Virgin Islands
North Sound, Virgin GordaSouth Sound, Virgin GordaAmet Sound on the northern coast of Nova Scotia on the Northumberland StraitBarkley Sound on the west coast of Vancouver Island, British ColumbiaBaynes Sound between Denman Island and Vancouver Island, British ColumbiaChatham Sound, off the North Coast of British ColumbiaClayoquot Sound in Vancouver Island, British ColumbiaCumberland Sound in Baffin Island's east coastDesolation Sound between the Discovery Islands and the coast of British ColumbiaEclipse Sound between Baffin Island and Bylot Island in NunavutEureka Sound between Ellesmere Island and Axel Heiberg Island in NunavutFitz Hugh Sound on the Central Coast of British ColumbiaHamilton Sound between Fogo Island and the Island of NewfoundlandHowe Sound, an inlet northwest of Vancouver, British ColumbiaJones Sound between Devon Island and Ellesmere Island in NunavutKyuquot Sound on the west coast of Vancouver Island, British ColumbiaLancaster Sound between Devon Island and Baffin Island in NunavutMassey Sound between Amund Ringnes Island and Axel Heiberg Island in NunavutNansen Sound between Ellesmere Island and Axel Heiberg Island in NunavutNewman Sound in Terra Nova National Park, Newfoundland and LabradorNootka Sound on the west coast of Vancouver Island, British ColumbiaNorthumberland Sound between Maclean Strait and Norwegian Bay, NunavutOwen Sound in OntarioParry Sound in OntarioPeel Sound between Prince of Wales Island and Somerset Island in NunavutQuatsino Sound on northern Vancouver IslandQueen Charlotte Sound off British ColumbiaRandom Sound near Clarenville in Newfoundland and LabradorRoes Welcome Sound between Southampton Island and Hudson Bay's west shore in NunavutSevern Sound in OntarioViscount Melville Sound between Banks Island and Melville Island in NunavutCayman Islands
Frank Sound on Grand CaymanLittle Sound on Grand CaymanNorth Sound on Grand CaymanSouth Hole Sound on Little CaymanSouth Sound on Grand CaymanAlmirantazgo SoundDarwin SoundOtway SoundReloncaví SoundSkyring SoundÚltima Esperanza SoundFalkland Islands
Adventure Sound in East FalklandBerkeley Sound in East FalklandByron Sound in West FalklandChoiseul Sound in East FalklandFalkland Sound between East Falkland and West FalklandThe Sound of Chausey.Ireland
Achill Sound, that separates Achill Island from the mainlandCampeche Sound in CampecheNew Zealand
"The Marlborough Sounds" is a local term for a complex of bays and inlets on the northern tip of South Island, which comprises two main sounds:Queen Charlotte Sound (New Zealand)Pelorus Sound, New ZealandMuch further south, there are many sounds in the southwestern tip of South Island. From north to south they are:
Milford SoundBligh SoundGeorge SoundCharles SoundNancy SoundDoubtful SoundDagg SoundBreaksea SoundDusky SoundDinagat Sound, separates the islands of Dinagat and SiargaoMalampaya Sound, in the Province of Palawan. The Malampaya Natural Gas Project is named after this area because it is close to it.Scandinavia
The Sound, another name for Øresund, a body of water between Sweden and DenmarkOn the coasts of (western) Baltic Sea and Norway there are more than a hundred straits named "Sund" (the Scandinavian and German version of "sound"), mostly in connection with the name of the island they divide from the continent or a mainland.Solomon Islands
New Georgia SoundCalf Sound between Isle of Man and the Calf of ManHeigham Sound, connected by Candle Dyke to the River Thurne, NorfolkPlymouth Sound in Plymouth, DevonSounds of ScotlandAlbemarle Sound in North CarolinaAnna Maria Sound in FloridaBack Sound in North CarolinaBlock Island Sound between Block Island and mainland Rhode IslandBogue Sound in North CarolinaBreton Sound in LouisianaBroad Sound near BostonCalibogue Sound in South CarolinaCore Sound in North CarolinaCroatan Sound in North CarolinaCross Sound in AlaskaCurrituck Sound in North CarolinaFrederick Sound in AlaskaHobe Sound in FloridaKotzebue Sound in AlaskaLong Island Sound between Long Island, New York and ConnecticutMississippi Sound in Mississippi and AlabamaNantucket Sound off Nantucket, MassachusettsNorton Sound in AlaskaPamlico Sound in North CarolinaPine Island Sound near Cape Coral, FloridaPort Royal Sound in South CarolinaPrince William Sound in AlaskaPuget Sound in WashingtonRhode Island Sound off Rhode IslandRoanoke Sound in North CarolinaSaint Helena Sound near Beaufort, South CarolinaSt. George Sound in Appalachicola Bay, FloridaSt. Simons Sound in Glynn County, GeorgiaSalisbury Sound in AlaskaSanta Rosa Sound in the Florida PanhandleSitka Sound in AlaskaSomes Sound in Mount Desert Island, Maine (arguably a fjard)Tangier Sound in Maryland & Virginia on Chesapeake BayVineyard Sound off Martha's Vineyard, MassachusettsUnited States Virgin Islands
Pillsbury Sound between Saint Thomas and Saint John