HOME

TheInfoList

Click Here for Items Related To - Lombard Effect

OR:

Lombard Effect on: [Wikipedia] [Google] [Amazon]

250 px, noise polluted urban surroundings than quieter ones to help overcome the auditory masking">noise_pollution.html" ;"title="Great tits sing at a higher frequency in noise pollution">noise polluted urban surroundings than quieter ones to help overcome the auditory masking that would otherwise impair other birds hearing their bird vocalization">song A song is a musical composition performed by the human voice. The voice often carries the melody (a series of distinct and fixed pitches) using patterns of sound and silence. Songs have a structure, such as the common ABA form, and are usu ...

. Although great tits achieve a change in song frequency by switching song types, in other urban birds the change in frequency might be related to the Lombard effect. For instance, in humans, the Lombard effect results in speakers adjusting frequency The Lombard effect or Lombard reflex is the Volition (psychology), involuntary tendency of speakers to increase their vocal effort when speaking in loudness, loud noise to enhance the audibility of their

voice The human voice consists of sound made by a human being using the vocal tract, including talking, singing, laughing, crying, screaming, shouting, humming or yelling. The human voice frequency is specifically a part of human sound produ ...

. This change includes not only loudness but also other acoustic features such as pitch, rate, and duration of

syllable A syllable is a basic unit of organization within a sequence of speech sounds, such as within a word, typically defined by linguists as a ''nucleus'' (most often a vowel) with optional sounds before or after that nucleus (''margins'', which are ...

s. This compensation effect maintains the auditory

signal-to-noise ratio Signal-to-noise ratio (SNR or S/N) is a measure used in science and engineering that compares the level of a desired signal to the level of background noise. SNR is defined as the ratio of signal power to noise power, often expressed in deci ...

of the speaker's

spoken words Language is a structured system of communication that consists of grammar and vocabulary. It is the primary means by which humans convey meaning, both in spoken and signed forms, and may also be conveyed through writing. Human language is ch ...

. The effect links to the needs of effective communication, as there is a reduced effect when words are repeated or lists are read where communication intelligibility is not important. Since the effect is involuntary it is used as a means to detect

malingering Malingering is the fabrication, feigning, or exaggeration of physical or psychological symptoms designed to achieve a desired outcome, such as personal gain, relief from duty or work, avoiding arrest, receiving medication, or mitigating prison se ...

in those simulating

hearing loss Hearing loss is a partial or total inability to hear. Hearing loss may be present at birth or acquired at any time afterwards. Hearing loss may occur in one or both ears. In children, hearing problems can affect the ability to acquire spo ...

. Research on birds and monkeys find that the effect also occurs in the vocalizations of animals. The effect was discovered in 1909 by Étienne Lombard, a French

otolaryngologist Otorhinolaryngology ( , abbreviated ORL and also known as otolaryngology, otolaryngology–head and neck surgery (ORL–H&N or OHNS), or ear, nose, and throat (ENT)) is a surgical subspecialty within medicine that deals with the surgical an ...

Lombard speech

Listeners hear a speech recorded with background noise better than they hear a speech which has been recorded in quiet with masking noise applied afterwards. This is because changes between normal and Lombard speech include: * increase in phonetic

fundamental frequencies The fundamental frequency, often referred to simply as the ''fundamental'' (abbreviated as 0 or 1 ), is defined as the lowest frequency of a periodic waveform. In music, the fundamental is the musical pitch of a note that is perceived as the l ...

* shift in energy from low frequency bands to middle or high bands * increase in

sound intensity Sound intensity, also known as acoustic intensity, is defined as the power carried by sound waves per unit area in a direction perpendicular to that area, also called the sound power density and the sound energy flux density. The SI unit of inte ...

* increase in

vowel A vowel is a speech sound pronounced without any stricture in the vocal tract, forming the nucleus of a syllable. Vowels are one of the two principal classes of speech sounds, the other being the consonant. Vowels vary in quality, in loudness a ...

duration * spectral tilting (or flattening): In normal speech, the spectral power at lower frequencies is much higher than the spectral power at higher frequencies. In Lombard speech, the spectral power at lower frequencies is not much higher than the spectral power at higher frequencies. * shift in

formant In speech science and phonetics, a formant is the broad spectral maximum that results from an acoustic resonance of the human vocal tract. In acoustics, a formant is usually defined as a broad peak, or local maximum, in the spectrum. For harmo ...

center frequencies for F1 (mainly) and F2 * the duration of

content word Content words, in linguistics, are words that possess semantic content and contribute to the meaning of the sentence in which they occur. In a traditional approach, nouns were said to name objects and other entities, lexical verbs to indicate acti ...

s are prolonged to a greater degree in noise than

function word In linguistics, function words (also called functors) are words that have little lexical meaning or have ambiguous meaning and express grammatical relationships among other words within a sentence, or specify the attitude or mood of the speak ...

s * greater lung volumes are used, * it is accompanied by larger facial movements, though these do not aid as much as sound changes Though sometimes called the Lombard "reflex", it can be deliberately controlled in humans. These changes cannot be controlled by instructing a person to speak as they would in silence, though people can learn control with feedback. The Lombard effect also occurs following

laryngectomy Laryngectomy is the removal of the larynx. In a total laryngectomy, the entire larynx is removed (including the vocal folds, hyoid bone, epiglottis, thyroid and cricoid cartilage and a few tracheal cartilage rings) with the separation of the a ...

when people following

speech therapy Speech is the use of the human voice as a medium for language. Spoken language combines vowel and consonant sounds to form units of meaning like words, which belong to a language's lexicon. There are many different intentional speech acts, suc ...

talk with

esophageal speech Esophageal speech, also known as esophageal voice, is an airstream mechanism for speech that involves oscillation of the esophagus. This contrasts with traditional laryngeal speech, which involves oscillation of the vocal folds. In esophageal s ...

Mechanisms

The intelligibility of an individual's own vocalization can be adjusted with audio-vocal reflexes using their own hearing (private loop), or it can be adjusted indirectly in terms of how well listeners can hear the vocalization (public loop). Both processes are involved in the Lombard effect.

Private loop

A speaker can regulate their vocalizations, particularly their amplitude relative to background noise, with reflexive auditory feedback. Such auditory feedback is known to maintain the production of vocalization since deafness affects the vocal acoustics of both humans and songbirds Changing the auditory feedback also changes vocalization in human speech or bird song. Neural circuits have been found in the

brainstem The brainstem (or brain stem) is the posterior stalk-like part of the brain that connects the cerebrum with the spinal cord. In the human brain the brainstem is composed of the midbrain, the pons, and the medulla oblongata. The midbrain is conti ...

that enable such reflex adjustment.

Public loop

A speaker can regulate their vocalizations at higher cognitive level in terms of observing its consequences on their audience's ability to hear it. This auditory self-monitoring adjusts vocalizations in terms of learnt associations of what features of their vocalization, when made in noise, create effective and efficient communication. The Lombard effect has been found to be greatest upon those words that are important to the listener to understand a speaker suggesting such cognitive effects are important.

Development

Both private and public loop processes exist in children. There is a

development Development or developing may refer to: Arts *Development (music), the process by which thematic material is reshaped * Photographic development *Filmmaking, development phase, including finance and budgeting * Development hell, when a proje ...

shift however from the Lombard effect being linked to acoustic self-monitoring in young children to the adjustment of vocalizations to aid its intelligibility for others in adults.

Neurology

The Lombard effect depends upon audio-vocal neurons in the periolivary region of the

superior olivary complex The superior olivary complex (SOC) or superior olive is a collection of brainstem nuclei that is located in pons, functions in multiple aspects of hearing and is an important component of the ascending and descending auditory pathways of the aud ...

and the adjacent pontine

reticular formation The reticular formation is a set of interconnected nuclei in the brainstem that spans from the lower end of the medulla oblongata to the upper end of the midbrain. The neurons of the reticular formation make up a complex set of neural networks ...

. It has been suggested that the Lombard effect might also involve the higher cortical areas that control these lower brainstem areas.

Choral singing

Choral singers experience reduced

feedback Feedback occurs when outputs of a system are routed back as inputs as part of a chain of cause and effect that forms a circuit or loop. The system can then be said to ''feed back'' into itself. The notion of cause-and-effect has to be handle ...

due to the sound of other singers upon their own voice. This results in a tendency for people in choruses to sing at a louder level if it is not controlled by a

conductor Conductor or conduction may refer to: Biology and medicine * Bone conduction, the conduction of sound to the inner ear * Conduction aphasia, a language disorder Mathematics * Conductor (ring theory) * Conductor of an abelian variety * Cond ...

. Trained singers can resist this effect but it has been suggested that after a concert they might speak more loudly in noisy surroundings, such as after-concert parties. The Lombard effect also occurs to those playing instruments such as the

guitar The guitar is a stringed musical instrument that is usually fretted (with Fretless guitar, some exceptions) and typically has six or Twelve-string guitar, twelve strings. It is usually held flat against the player's body and played by strumming ...

Animal vocalization

Noise has been found to affect the vocalizations of animals that vocalize against a background of human

noise pollution Noise pollution, or sound pollution, is the propagation of noise or sound with potential harmful effects on humans and animals. The source of outdoor noise worldwide is mainly caused by machines, transport and propagation systems.Senate Publi ...

. Outside of humans, it was first demonstrated in 1972 on Japanese quails. Some of the animals for which the Lombard effect has also been found in the vocalization are: *

Budgerigar The budgerigar ( ; ''Melopsittacus undulatus''), also known as the common parakeet, shell parakeet or budgie ( ), is a small, long-tailed, seed-eating parrot native to Australia. Naturally the species is green and yellow with black, scallop ...

s * Canaries *

Cat The cat (''Felis catus''), also referred to as the domestic cat or house cat, is a small domesticated carnivorous mammal. It is the only domesticated species of the family Felidae. Advances in archaeology and genetics have shown that the ...

s *

Chicken The chicken (''Gallus gallus domesticus'') is a domesticated subspecies of the red junglefowl (''Gallus gallus''), originally native to Southeast Asia. It was first domesticated around 8,000 years ago and is now one of the most common and w ...

s *

Common marmoset The common marmoset (''Callithrix jacchus''), also called white-tufted marmoset or white-tufted-ear marmoset, is a New World monkey. It originally lived on the northeastern coast of Brazil, in the states of Piauí, Paraíba, Ceará, Rio Grande d ...

s *

Cottontop tamarin The cotton-top tamarin (''Saguinus oedipus'') is a small New World monkey weighing less than . This New World monkey can live up to 24 years, but most of them die by 13 years. One of the smallest primates, the cotton-top tamarin is easily recog ...

s * Japanese quail *

Nightingale The common nightingale, rufous nightingale or simply nightingale (''Luscinia megarhynchos''), is a small passerine bird which is best known for its powerful and beautiful song. It was formerly classed as a member of the thrush family Turdidae, ...

s *

Rhesus macaque The rhesus macaque (''Macaca mulatta''), colloquially rhesus monkey, is a species of Old World monkey. There are between six and nine recognised subspecies split between two groups, the Chinese-derived and the Indian-derived. Generally brown or g ...

s *

Squirrel monkey Squirrel monkeys are New World monkeys of the genus ''Saimiri''. ''Saimiri'' is the only genus in the subfamily Saimiriinae. The name of the genus is of Tupi origin (''sai-mirím'' or ''çai-mbirín'', with ''sai'' meaning 'monkey' and ''mirím' ...

Zebra finch The zebra finches are two species of estrildid finch in the genus ''Taeniopygia'' found in Australia and Indonesia. They are seed-eaters that travel in large flocks. Species The species are: Previously, both species were classified as ...

es * Beluga whales * Pale spear-nosed bats * Túngara frogs *

Bat Bats are flying mammals of the order Chiroptera (). With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most birds, flying with their very long spread-out ...

s Some frogs can vary their call amplitude, but do not use this capacity for communication in noise. For example, in the presence of noise, Cope's gray treefrogs raise call duration and rate, but not amplitude. When echolocating in broadband noise, ''

Tadarida brasiliensis The Mexican free-tailed bat or Brazilian free-tailed bat (''Tadarida brasiliensis'') is a medium-sized bat native to North, Central, and South America and the Caribbean, so named because its tail can be almost half its total length and is not a ...

'' increase their call amplitude, duration and bandwidth simultaneously. Similarly for human speech, monkey calls and bird vocalizations.

References

{{DEFAULTSORT:Lombard Effect Phonetics Human voice Animal communication Human communication Noise pollution