Sounding generally refers to a mechanism of probing the environment by sending out some kind of stimulus. The term derives from the ancient practice of determining the depth of water (making a sounding) by feeding out a line with a weight at the end.

In biology, organisms employ a variety of sensory modalities for sounding: touch (antennae

Antenna (biology)

Antennae in biology have historically been paired appendages used for sensing in arthropods. More recently, the term has also been applied to cilium structures present in most cell types of eukaryotes....

, whiskers), vibration (spider

Spider

Spiders are air-breathing arthropods that have eight legs, and chelicerae with fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other groups of organisms...

s), electrical (fish

Electric fish

An electric fish is a fish that can generate electric fields. It is said to be electrogenic; a fish that has the ability to detect electric fields is said to be electroreceptive. Most electrogenic fish are also electroreceptive. Electric fish species can be found both in the sea and in freshwater...

), chemical (Phycomyces blakesleeanus

Phycomyces blakesleeanus

Phycomyces blakesleeanus is a filamentous fungus in the Order Mucorales of the phylum Zygomycota or subphylum Mucormycotina. The spore-bearing sporangiophores of Phycomyces are very sensitive to different environmental signals including light, gravity, wind, chemicals and adjacent objects...

), temperature (diving reflex), and perhaps light (flashlight fish

Flashlight fish

The flashlight fish are a family, the Anomalopidae, of beryciform fish. There are some unrelated fish with similar features, some of which are also called flashlight fish. Notable among these are the deep sea lanternfish, of the family Myctophidae, of which there are over 200 species.Flashlight...

).

Sounding can refer to:

• Depth sounding
  Depth Sounding
  Depth sounding refers to a historical nautical term for measuring depth; it is often referred to simply as sounding. Sounding is finding the depth of a given point in a body of water. Sounding data is used in bathymetry to make maps of the floor of a body of water. Soundings were traditionally...
  
  , the determination of the depth of water usually in the sea.
  • Originally using a weighted line called a lead line
    Sounding line
    A sounding line or lead line is a length of thin rope with a plummet, generally of lead, at its end. Regardless of the actual composition of the plummet, it is still called a "lead."...
    
    
  • More recently using Echo sounding
    Echo sounding
    Echo sounding is the technique of using sound pulses directed from the surface or from a submarine vertically down to measure the distance to the bottom by means of sound waves. This information is then typically used for navigation purposes or in order to obtain depths for charting purposes...
    
    
• Whale sounding
  Whale sounding
  Sounding is a term used for whales diving. It is typically only used for longer dives. Whales typically stay close to the surface for a series of short, shallow dives while building their oxygen reserves. They then have a sounding dive....
  
  , the act of diving by whales
• an atmospheric sounding
  Atmospheric sounding
  An atmospheric sounding is a measurement of vertical distribution of physical properties of the atmospheric column such as pressure, temperature, wind speed and wind direction , liquid water content, ozone concentration, pollution, and other properties...
  
  
• various methods in telecommunication
  Telecommunication
  Telecommunication is the transmission of information over significant distances to communicate. In earlier times, telecommunications involved the use of visual signals, such as beacons, smoke signals, semaphore telegraphs, signal flags, and optical heliographs, or audio messages via coded...
  
  s
  • Ionospheric sounding
    Ionospheric sounding
    In telecommunication and radio science, an ionospheric sounding is a technique that provides real-time data on high-frequency ionospheric-dependent radio propagation, using a basic system consisting of a synchronized transmitter and receiver....
    
    
  • Automatic sounding
    Automatic sounding
    In telecommunication, automatic sounding is the testing of selected channels for quality by providing a very brief identifying transmission that may be used by other stations to evaluate connectivity, and availability, and to identify known working channels for immediate or later use for...
    
    
  • Automatic link establishment
    Automatic link establishment
    Automatic Link Establishment, commonly known as ALE, is the worldwide de facto standard for digitally initiating and sustaining HF radio communications. ALE is a feature in an HF communications radio transceiver system, that enables the radio station to make contact, or initiate a circuit, between...
    
    
• In medicine
  Medicine
  Medicine is the science and art of healing. It encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness....
  
   and surgery
  Surgery
  Surgery is an ancient medical specialty that uses operative manual and instrumental techniques on a patient to investigate and/or treat a pathological condition such as disease or injury, or to help improve bodily function or appearance.An act of performing surgery may be called a surgical...
  
  , any use of a Sound (medical instrument)
  Sound (medical instrument)
  In medicine, sounds are instruments for probing and dilating passages within the body, the best-known examples of which are urethral sounds and uterine sounds. Some people enjoy using them for urethral play.-Urethral sounds:...
  
  , such as
  • Urethral sounding
    Urethral sounding
    Sounding or urethral sounding is the medical use of probes called sounds to increase the inner diameter of the urethra and to locate obstructions in it...
    
    
• various methods in geophysics
  Geophysics
  Geophysics is the physics of the Earth and its environment in space; also the study of the Earth using quantitative physical methods. The term geophysics sometimes refers only to the geological applications: Earth's shape; its gravitational and magnetic fields; its internal structure and...
  
  :
  • vertical electrical sounding (VES), see Schlumberger brothers
    Schlumberger brothers
    Conrad Schlumberger and Marcel Schlumberger were brothers from the Alsace region in France...
    
    
  • electromagnetic
    Electromagnetism
    Electromagnetism is one of the four fundamental interactions in nature. The other three are the strong interaction, the weak interaction and gravitation...
    
     sounding
    Cone penetration test
    The cone penetration test is an gouda cpt testing method used to determine the geotechnical engineering properties of soils and delineating soil stratigraphy. It was initially developed in the 1950s at the Dutch Laboratory for Soil Mechanics in Delft to investigate soft soils. Based on this...
    
    
• sounding rocket
  Sounding rocket
  A sounding rocket, sometimes called a research rocket, is an instrument-carrying rocket designed to take measurements and perform scientific experiments during its sub-orbital flight. The origin of the term comes from nautical vocabulary, where to sound is to throw a weighted line from a ship into...
  
  s which take measurements during suborbital flight
• Tank sounding, a means of determining the quantity of fluid inside a tank by measuring the height of its surface from the bottom of a tank.

See also

• Sound
  Sound (disambiguation)
  Sound is audible sense perceived by the brain.Sound may also refer to:*Sound , verb meaning to take depth readings of fluids in a tank or around a ship...
  
  
• Soundings
  Soundings (disambiguation)
  Soundings may refer to:*Soundings , a British political journal of the new left*Soundings , a radio drama series produced by Jeff Green...