A hum is a

sound In physics, sound is a vibration that propagates as an acoustic wave, through a transmission medium such as a gas, liquid or solid. In human physiology and psychology, sound is the ''reception'' of such waves and their ''perception'' by ...

made by producing a wordless tone with the mouth closed, forcing the sound to emerge from the

nose A nose is a protuberance in vertebrates that houses the nostrils, or nares, which receive and expel air for respiration alongside the mouth. Behind the nose are the olfactory mucosa and the sinuses. Behind the nasal cavity, air next passe ...

. To hum is to produce such a sound, often with a

melody A melody (from Greek μελῳδία, ''melōidía'', "singing, chanting"), also tune, voice or line, is a linear succession of musical tones that the listener perceives as a single entity. In its most literal sense, a melody is a combina ...

. It is also associated with thoughtful absorption, 'hmm'. A hum has a particular

timbre In music, timbre ( ), also known as tone color or tone quality (from psychoacoustics), is the perceived sound quality of a musical note, sound or tone. Timbre distinguishes different types of sound production, such as choir voices and musica ...

(or sound quality), usually a

monotone Monotone refers to a sound, for example music or speech, that has a single unvaried tone. See: monophony. Monotone or monotonicity may also refer to: In economics *Monotone preferences, a property of a consumer's preference ordering. *Monotonic ...

or with slightly varying tones. There are other similar sounds not produced by human singing that are also called hums, as the sound produced by

machinery A machine is a physical system using power to apply forces and control movement to perform an action. The term is commonly applied to artificial devices, such as those employing engines or motors, but also to natural biological macromolecul ...

in operation, such as a

microwave Microwave is a form of electromagnetic radiation with wavelengths ranging from about one meter to one millimeter corresponding to frequencies between 300 MHz and 300 GHz respectively. Different sources define different frequency ra ...

, or by an

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pa ...

in flight. The

hummingbird Hummingbirds are birds native to the Americas and comprise the Family (biology), biological family Trochilidae. With about 361 species and 113 genus, genera, they occur from Alaska to Tierra del Fuego, but the vast majority of the species are ...

was named for the sound that bird makes in flight which sounds like a hum.

Mechanics

A 'hum' or 'humming' by humans is created by the resonance of air in various parts of passages in the head and throat, in the act of breathing. The 'hum' that a hummingbird creates is also created by resonance: in this case by air resistance against wings in the actions of flying, especially of hovering.

Humming in human evolution

Joseph Jordania Joseph Jordania ( Georgian იოსებ ჟორდანია, born February 12, 1954 and also known under the misspelling of Joseph Zhordania) is an Australian– Georgian ethnomusicologist and evolutionary musicologist and professor. He ...

suggested that humming could have played an important role in the early human (hominid) evolution as

contact calls Contact calls are seemingly haphazard sounds made by many social animals (such as a chicken's cluck). Contact calls are unlike other calls (such as alarm calls) in that they are not usually widely used, conspicuous calls, but rather short exclamatio ...

. Many social animals produce seemingly haphazard and indistinct sounds (like chicken cluck) when they are going about their everyday business (foraging, feeding). These sounds have two functions: (1) to let group members know that they are among kin and there is no danger, and (2) in case of the appearance of any signs of danger (suspicious sounds, movements in a forest), the animal that notices danger first, stops moving, stops producing sounds, remains silent and looks in the direction of the danger sign. Other animals quickly follow suit and very soon all the group is silent and is scanning the environment for possible danger.

Charles Darwin Charles Robert Darwin ( ; 12 February 1809 – 19 April 1882) was an English naturalist, geologist, and biologist, widely known for his contributions to evolutionary biology. His proposition that all species of life have descended ...

was the first to notice this phenomenon on the example of the wild horses and the cattle.

suggested that for humans, as for many social animals, silence can be a sign of danger, and that's why gentle humming and musical sounds relax humans (see the use of gentle music in

music therapy Music therapy, an allied health profession, "is the clinical and evidence-based use of music interventions to accomplish individualized goals within a therapeutic relationship by a credentialed professional who has completed an approved music t ...

, lullabies).

Humming in language

In Pirahã, the only surviving dialect of the Mura language, there is a special register of speech which uses solely humming, with

no audible release A stop with no audible release, also known as an unreleased stop or an applosive, is a stop consonant with no release burst: no audible indication of the end of its occlusion (hold). In the International Phonetic Alphabet, lack of an audible rele ...

Music

Humming is often used in music of genres, from classical (for example, the famous chorus at the end of Act 2 of

Giacomo Puccini Giacomo Puccini ( Lucca, 22 December 1858Bruxelles, 29 November 1924) was an Italian composer known primarily for his operas. Regarded as the greatest and most successful proponent of Italian opera after Verdi, he was descended from a long ...

's ''

Madama Butterfly ''Madama Butterfly'' (; ''Madame Butterfly'') is an opera in three acts (originally two) by Giacomo Puccini, with an Italian libretto by Luigi Illica and Giuseppe Giacosa. It is based on the short story " Madame Butterfly" (1898) by John Lu ...

'') to jazz to R&B. Another form of music derived from basic humming is the humwhistle. Folk art, also known as "whistle-hum," produces a high pitch and low pitch simultaneously. The two-tone sound is related to

field holler The field holler or field call is mostly a historical type of vocal work song sung by field slaves in the United States (and later by African American forced laborers accused of violating vagrancy laws) to accompany their tasked work, to commun ...

, overtone singing, and

yodeling Yodeling (also jodeling) is a form of singing which involves repeated and rapid changes of pitch between the low-pitch chest register (or "chest voice") and the high-pitch head register or falsetto. The English word ''yodel'' is derived from the ...

the music.

References

External links