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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.html" "title="auditory_masking.html" ;"title="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">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 intended to be performed by the human voice. This is often done at distinct and fixed pitches (melodies) using patterns of sound and silence. Songs contain various forms, such as those including the repetitio ...

. 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 production in ...

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

syllable A syllable is a unit of organization for a sequence of speech sounds typically made up of a syllable nucleus (most often a vowel) with optional initial and final margins (typically, consonants). Syllables are often considered the phonological "bu ...

s. This compensation effect maintains the auditory

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

ratio of the speaker's spoken words. 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 relief from duty or work. Malingering is not a medical diagnosis, but may be recorded as a "focus of c ...

in those simulating

hearing loss Hearing loss is a partial or total inability to Hearing, 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 Language ...

. 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 subspeciality within medicine that deals with the surgical a ...

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'', is defined as the lowest frequency of a Periodic signal, periodic waveform. In music, the fundamental is the musical pitch (music), pitch of a note that is perceived as ...

* 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. The SI unit of intensity, which includes sound intensity, is the watt per square meter (W/m2 ...

* increase in

vowel A vowel is a syllabic speech sound pronounced without any stricture in the vocal tract. Vowels are one of the two principal classes of speech sounds, the other being the consonant. Vowels vary in quality, in loudness and also in quantity (leng ...

duration * spectral tilting * 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 harmoni ...

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 words * greater lung volumes are used, * it is accompanied by larger facial movements, though these do not aid as much as sound changes 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 and separation of the airway from the mouth, nose and esophagus. In a total laryngectomy, the entire larynx is removed (including the vocal folds, hyoid bone, epiglottis, Thyroid cartilage, thyroid and cr ...

when people following

speech therapy Speech is a human vocal communication using language. Each language uses phonetic combinations of vowel and consonant sounds that form the sound of its words (that is, all English words sound different from all French words, even if they are th ...

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 sp ...

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 cont ...

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. In 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 hell, when a project is stuck in development *Filmmaking, development phase, including finance and budgeting *Development (music), the process thematic material is reshaped * Photograph ...

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 functions in multiple aspects of hearing and is an important component of the ascending and descending auditory pathways of the auditory system. The SO ...

and the adjacent pontine

reticular formation The reticular formation is a set of interconnected nuclei that are located throughout the brainstem. It is not anatomically well defined, because it includes neurons located in different parts of the brain. The neurons of the reticular formation ...

. 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 handled ...

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. Trained soloists can control 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 fretted musical instrument that typically has six strings. It is usually held flat against the player's body and played by strumming or plucking the strings with the dominant hand, while simultaneously pressing selected stri ...

Animal vocalization

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

noise pollution Noise pollution, also known as environmental noise or sound pollution, is the propagation of noise with ranging impacts on the activity of human or animal life, most of them are harmful to a degree. The source of outdoor noise worldwide is main ...

. Experimentally, the Lombard effect has also been found in the vocalization of: *

Budgerigar The budgerigar ( ; ''Melopsittacus undulatus''), also known as the common parakeet or shell parakeet, is a small, long-tailed, seed-eating parrot usually nicknamed the budgie ( ), or in American English, the parakeet. Budgies are the only spe ...

s * Canaries *

Cat The cat (''Felis catus'') is a domestic species of small carnivorous mammal. It is the only domesticated species in the family Felidae and is commonly referred to as the domestic cat or house cat to distinguish it from the wild members of ...

s *

Chicken The chicken (''Gallus gallus domesticus'') is a domesticated junglefowl species, with attributes of wild species such as the grey and the Ceylon junglefowl that are originally from Southeastern Asia. Rooster or cock is a term for an adult m ...

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 Piaui, Paraiba, Ceará, Rio Grande do ...

s * Cottontop tamarins *

Japanese quail The Japanese quail (''Coturnix japonica''), also known as the coturnix quail, is a species of Old World quail found in East Asia. First considered a subspecies of the common quail, it is now considered as a separate species. The Japanese quail ...

Nightingale The common nightingale, rufous nightingale or simply nightingale (''Luscinia megarhynchos''), is a small passerine bird best known for its powerful and beautiful song. It was formerly classed as a member of the thrush family Turdidae, but is no ...

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 that are split between two groups, the Chinese-derived and the Indian-derived. Generally b ...

s *

Squirrel monkey Squirrel monkeys are New World monkeys of the genus ''Saimiri''. ''Saimiri'' is the only genus in the subfamily Saimirinae. 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. The species are: Previously, both species were classified as a single species ...

es *

Beluga whale The beluga whale () (''Delphinapterus leucas'') is an Arctic and sub-Arctic cetacean. It is one of two members of the family Monodontidae, along with the narwhal, and the only member of the genus ''Delphinapterus''. It is also known as the whi ...

s * Pale spear-nosed bats *

Túngara frog The Túngara frog (''Engystomops pustulosus'') is a species of frog in the family Leptodactylidae. It is a small nocturnal terrestrial frog found in Mexico, Central America, and the northeastern regions of South America. The tungara frog exhib ...

References

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