Lombard effect
The Lombard effect or Lombard reflex is the involuntary tendency of speakers to increase their vocal effort when speaking in loud noise to enhance the audibility of their voice.[5] This change includes not only loudness but also other acoustic features such as pitch, rate, and duration of syllables.[6][7] This compensation effect maintains the auditory signal-to-noise 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.[5] Since the effect is involuntary it is used as a means to detect malingering in those simulating hearing loss. Research on birds[8][9] and monkeys[10] find that the effect also occurs in the vocalizations of animals.
The effect was discovered in 1909 by Étienne Lombard, a French otolaryngologist.[5][11]
- ^ Slabbekoorn H, Peet M (July 2003). "Ecology: Birds sing at a higher pitch in urban noise". Nature. 424 (6946): 267. Bibcode:2003Natur.424..267S. doi:10.1038/424267a. PMID 12867967. S2CID 4348883.
- ^ Halfwerk, W; Slabbekoorn (2009). "A behavioural mechanism explaining noise-dependent pitch shift in urban birdsong". Animal Behaviour. 78 (6): 1301–1307. doi:10.1016/j.anbehav.2009.09.015. S2CID 53191082.
- ^ Nemeth E., E; Brumm H. (2010). "Birds and Anthropogenic Noise: Are Urban Songs Adaptive?". American Naturalist. 176 (4): 465–475. doi:10.1086/656275. PMID 20712517. S2CID 39427649.
- ^ Derryberry, Elizabeth P.; Phillips, Jennifer N.; Derryberry, Graham E.; Blum, Michael J.; Luther, David (2020-10-30). "Singing in a silent spring: Birds respond to a half-century soundscape reversion during the COVID-19 shutdown". Science. 370 (6516): 575–579. doi:10.1126/science.abd5777. ISSN 0036-8075. PMID 32972991. S2CID 221914406.
- ^ a b c Lane H, Tranel B (1971). "The Lombard sign and the role of hearing in speech". J Speech Hear Res. 14 (4): 677–709. doi:10.1044/jshr.1404.677.
- ^ Junqua JC (January 1993). "The Lombard reflex and its role on human listeners and automatic speech recognizers". J. Acoust. Soc. Am. 93 (1): 510–24. Bibcode:1993ASAJ...93..510J. doi:10.1121/1.405631. PMID 8423266. Archived from the original on 2013-02-23.
- ^ Summers WV, Pisoni DB, Bernacki RH, Pedlow RI, Stokes MA (September 1988). "Effects of noise on speech production: acoustic and perceptual analyses". J. Acoust. Soc. Am. 84 (3): 917–28. Bibcode:1988ASAJ...84..917S. doi:10.1121/1.396660. PMC 3507387. PMID 3183209. Archived from the original on 2013-02-23.
- ^ Manabe K, Sadr EI, Dooling RJ (February 1998). "Control of vocal intensity in budgerigars (Melopsittacus undulatus): differential reinforcement of vocal intensity and the Lombard effect". J. Acoust. Soc. Am. 103 (2): 1190–8. Bibcode:1998ASAJ..103.1190M. doi:10.1121/1.421227. PMID 9479771.
- ^ Brumm H (June 2004). "Causes and consequences of song amplitude adjustment in a territorial bird: a case study in nightingales". An. Acad. Bras. Ciênc. 76 (2): 289–95. doi:10.1590/s0001-37652004000200017. PMID 15258642.
- ^ Sinnott JM, Stebbins WC, Moody DB (August 1975). "Regulation of voice amplitude by the monkey". J. Acoust. Soc. Am. 58 (2): 412–4. Bibcode:1975ASAJ...58..412S. doi:10.1121/1.380685. PMID 810506. Archived from the original on 2013-02-23.
- ^ Lombard É (1911). "Le signe de l'élévation de la voix". Annales des Maladies de l'Oreille et du Larynx. XXXVII (2): 101–9.