Babies learn to communicate through eye contact, gestures, and affectionate touch. But when it comes to grabbing a baby’s attention — and helping a baby “crack the code” of spoken language — one particular mode of communication may be especially effective.
How to babies learn language? You might argue that they simply have a knack for it. After all, babies perform some truly amazing feats.
- They listen to a sea of confused sound, and figure out that certain segments of sound are words.
- They teach themselves to reproduce the speech sounds they hear — by listening, babbling, making corrections, and babbling again.
- They infer the meanings of words by interacting with conversation partners and observing contingencies (noticing, for example, that you consistently say the word “water” when you give your baby a sippy cup of H2O).
However you look at it, it’s impressive. Without textbooks or dictionaries or explicit instruction, babies acquire language. But that doesn’t mean that babies work everything out on their own, without any help.
If you’ve ever struggled to understand a new language, you know that not every speaker is equally easy to understand. Some folks, noticing your difficulties, alter their normal speech patterns to make their meanings more obvious. Does the same thing happen for infants?
Enter Exhibit A: “infant-directed speech.”
What is infant-directed speech?
Also called “IDS,” “parentese,” or “motherese,” it’s a speech register that people seem to adopt naturally when they interact with a baby.
Suddenly their vocal pitch goes up. They speak more musically — using a wider pitch range, and a more exaggerated emotional tone. They may change the timbre of their voices, too, so they sound smoother, less rough.
In addition, they may repeat phrases, speak more slowly, and take extra care in pronunciation — hyper-articulating their vowels. They may also use shorter, simpler sentence structure, and emphasize certain words by uttering them in isolation. For example, instead of saying “Look at the teddy bear!” a parent might simply call out “Bear!” (Christia and Siedl 2013; Fernald 2000).
Do babies like infant-directed speech?
They do. In fact, when researchers have done experiments using audio playbacks, they’ve found that babies actually prefer IDS to regular, “adult-directed speech” (or “ADS”).
The effect has been documented in a wide range of age groups — from newborns all the way up children 18-21 months old (Cooper and Aslin 1990; Hayashi et al 2001; Schachner and Hannon 2011; Byers-Heinlein et al 2021). In fact, babies prefer infant-directed speech even in cases when the language itself is totally unfamiliar — a foreign language they have never heard before (Werker et al 1994).
And the thing is, this isn’t simply a question of putting a smile on your baby’s face. Experimental research also indicates suggests that babies’ brains pay more attention to infant-directed speech — processing it, or tracking it, more intensively than they do with adult-directed speech (Saito et al 2006; Zaigl and Mills 2007; Räsänen et al 2018; Kalashnikova et al 2018; Menn et al 2022).
Why is infant-directed speech so good at grabbing a baby’s attention?
In part, it’s because of the raised pitch. High-pitched vocalizations are used as attention-getters by many nonhuman animals, including monkeys (Koda and Masataka 2003). And it’s interesting to note that baby dogs really love it when we address them with high-pitched voices (Ben-Aderet et al 2017)! So maybe our infants are simply following that trend!
In addition, clever experients have confirmed that babies prefer infantile voices — voices that sound a lot like them (Massapollo et al 2016; Polka et al 2022). Is this because such voices sound less threatening (Kalashnikova et al 2017)? Maybe. But it’s probably also about learning to talk. Babies need to tune into their own voices, so they can practice making speech sounds, listen to their progress, and make the necessary tweaks to improve accuracy. So being more attracted to baby voices makes sense. It helps ensure that they will pay close attention to their own, developing, vocal skills.
Finally, it’s likely that babies are attracted to the musical, emotional tone of IDS. Given the choice, babies prefer listening to voices infused with emotion — especially happy emotion (Kao et al 2022). And a recent study suggests that it’s the musical rhythms of IDS that encourage the brain to engage in deeper processing (Menn 2022).
So how does infant-directed speech help babies understand our meanings?
We’ve already seen part of the answer: You are more likely to engage your baby’s attention when you use infant-directed speech. That’s a crucial prerequisite for all communication. But there’s more.
1. Infant-directed speech makes emotional intentions more obvious
Babies are in the process of learning language, so they don’t understand many of our words. But infant-directed speech comes with a kind of metaphorical megaphone — we tend to pump up the intensity of our emotional communication. And this helps get our message across.
For example, suppose I asked you to listen to a stranger speaking a language you don’t understand. Would you be able to make out his intentions, based on tone of voice alone? When researchers have performed tests like this, they’ve found that the speaker’s style matters. Infant-directed speech makes the emotional intentions more transparent and easier to grasp — for both babies (Fernald 1993) and adults (Bryant and Barret 2007; Bryant et al 2012).
2. Infant-directed speech helps babies decode spoken language
Experiments suggest that IDS can help babies develop crucial speech perception skills, including
- the ability to discriminate between different speech sounds;
- the ability to detect the boundaries between words in a stream of speech;
- the ability to recognize distinct clauses in a stream of speech; and
- the ability to “read lips,” or match visual cues to their corresponding speech sounds.
Does this imply that infant-directed speech is a kind of “tutorial” mode of baby communication? It seems to. In fact, there is even evidence suggesting that babies learn speech faster when their parents use particularly expressive forms of infant-directed speech.
For instance, in families where parents use infant-directed speech, babies who spend more time in one-on-one conversation develop better language skills (Ramírez-Esparza et al 2017). Moreover, toddlers tend to amass larger vocabularies — and learn new words more easily — if their mothers address them with a higher pitch (Han et al 2023; Han et al 2022).
Read more about it in my article, “Baby talk 101: How infant-directed speech helps babies learn language.”
Who uses infant-directed speech? Does everybody do it?
Well, no. Some adults don’t make any of the modifications we’ve mentioned. But it’s very common for people to adopt at least one of the characteristics of infant-directed speech, and in that sense, it’s the “normal” thing to do.
For example, in a recent international study, researchers asked volunteers from over 180 different countries to listen to a series of audio clips — brief monologues of unidentified adults speaking briefly in their native languages.
In some cases, the speakers had been addressing another adult. In others, they had been talking to a “fussy infant.” Could the volunteers tell which was which? People were quite accurate, even when they didn’t understand the speaker’s native language. When they heard speakers raising their pitch — or hyper-articulating their vowels — they tended to assume that they were listening to infant-directed speech (Hilton et al 2022).
Is infant-directed speech a human universal?
Not in the literal sense. As we’ve alread noted, infant-directed speech isn’t practiced absolutely everywhere by everyone. Parents who are depressed or self-conscious aren’t so good at ID speech (e.g., Kaplan et al 2007). And some parents may be discouraged by cultural attitudes.
For instance, anthropologists have reported that the Kaluli of New Guinea don’t engage their babies in conversation (Sheiffelin and Ochs 1996). It’s also been reported that the Quiché Mayan speak to their babies in the same pitch that they use to address adults (Ratner and Pye 1984).
Yet it’s clear that infant-directed speech is a widespread, cross-cultural phenomenon (Das 1989; Dil 1971, Ferguson 1964; Fernald et al 1989; Fernald and O’Neill 1993; Kelkar 1965; Meegaskumbura 1980; Saint-Georges et al 2013; Sulpizio et al 2017). It’s been documented in a wide range of languages, including languages indigenous to
- Africa and the Middle East (Arabic and Xhosa, a Bantu language)
- The Americas (Comanche)
- Australia (Warlpiri)
- East Asia (Cantonese, Mandarin, Korean, Japanese, and Gilyak, a Siberian language)
- South Asia (Bengali, Hindi, Marathi, and Sinhala, a Sri Lankan language)
- Europe (English, French, German, Italian, Latvian, and Swedish)
Moreover, when researchers recently analyzed speech samples in 21 different societies (including 4 small-scale societies lacking access to modern media) they found evidence everywhere that people tend to use a higher pitch when soothing an unhappy infant. And the researchers found that — in most societies — people addressed babies with a greater range of pitch and with more sharply-contrasting vowels (Hilton et al 2022).
So some researchers think of infant-directed speech as reflection of certain innate biases of our species. It isn’t universal, but it’s very common because humans everywhere possess similar perceptual systems and learning abilities. And this prompts us to address our babies in somewhat similar ways (Fernald 1992; Monnot 1998; Schick et al 2022).
Learning about language acquisition and how to support it
When do babies speak their first words? It depends a lot on how we define “word,” and whether we trust in the observations of everyday parents. I discuss the issues — and a fascinating experiment — in this article.
If you’re interested in what science tells us about the best ways to help babies learn language, see my article, “How to support language development in babies.” It summarizes the most important points in a series of practical parenting tips.
Learning about other modes of baby communication
Speech isn’t the only way that parents can talk with babies. As deaf parents know, babies are also receptive to learning sign language. Even babies of hearing parents may benefit from using gestures during speech. For more information, see this article on the science of baby signs.
What about teaching your baby to understand visual signs? I talk about this in my articles, “Baby sign language: A guide for the science-minded parent” and “Can babies sign before they speak?”
References: Better baby communication
Ben-Aderet T, Gallego-Abenza M, Reby D, Mathevon N. 2017. Dog-directed speech: why do we use it and do dogs pay attention to it? Proc Biol Sci. 284(1846):20162429.
Broesch T and Bryant GA. 2017. Fathers’ Infant-Directed Speech in a Small-Scale Society. Child Dev. 89(2):e29-e41.
Bryant G A, Liénard P, and Barrett HC. 2012. Recognizing infant-directed speech across distant cultures Journal of Evolutionary Psychology 10: 47-59.
Bryant GA and Barrett HC. 2007. Recognizing intentions in infant-directed speech: evidence for universals: Psychol Sci. 18(8):746-51.
Burnham D, Kitamura C, and Vollmer-Conna U. 2002. What’s new, pussycat? On talking to babies and animals. Science 296(5572):1435.
Byers-Heinlein K, Tsui ASM, Bergmann C, Black AK, Brown A, Carbajal MJ, Durrant S, Fennell CT, Fiévet AC, Frank MC, Gampe A, Gervain J, Gonzalez-Gomez N, Hamlin JK, Havron N, Hernik M, Kerr S, Killam H, Klassen K, Kosie JE, Kovács ÁM, Lew-Williams C, Liu L, Mani N, Marino C, Mastroberardino M, Mateu V, Noble C, Orena AJ, Polka L, Potter CE, Schreiner M, Singh L, Soderstrom M, Sundara M, Waddell C, Werker JF, Wermelinger S. 2021. A multi-lab study of bilingual infants: Exploring the preference for infant-directed speech. Adv Methods Pract Psychol Sci. 4(1):10.
Cristia A and Seidl A. 2013. The hyperarticulation hypothesis of infant-directed speech. J Child Lang. 13:1-22.
Cooper RP and Aslin RN. 1994. Developmental differences in infant attention to the spectral properties of infant-directed speech. Child Dev. 65(6):1663-77.
Das, V. 1989. Voices of children. Daedalus 118: 263-294.
Dil A. 1971. Bengali baby talk. Word 27:11-27.
D’Odorico L and Jacob V. 2006. Prosodic and lexical aspects of maternal linguistic input to late-talking toddlers. Int J Lang Commun Disord. 41(3):293-311.
Golinkoff RM and Alioto A. 1995. Infant-directed speech facilitates lexical learning in adults hearing Chinese: implications for language acquisition. J Child Lang. 22(3):703-26.
Ferguson CA. 1964. Baby talk in six languages. American Anthropologist 66: 103-114.
Fernald A. 2000. Speech to infants as hyperspeech: Knowledge-driven processes in early word recognition. Phonetic 57: 242-254.
Fernald A. 1993. Approval and disapproval: Infant responsiveness to vocal affect in familiar and unfamiliar languages Child development 64 (3): 657-674
Fernald A. 1992. Human maternal vocalizations to infants as biologically relevant signals: An evolutionary perspective. In: JH Barkow, L Cosmides and J Tooby (eds), The Adapted Mind: Evolutionary psychology and the generation of culture (pp. 391-428). New York: Oxford University Press
Fernald A, McRoberts GW, and Swingley D. 2001. Infants’ developing competence in recognizing and understanding words in fluent speech. In J. Weissenborn and B. Hohle (eds.) Approaches to bootstrapping: Phonological, lexical, syntactic and neurophysiological aspects of early language acquisition, Vol. I. Amsterdam: John Benjamins.
Fernald A and O’Neill DK. 1993. Peekaboo across cultures: how mothers and infants play with voices, faces, and expectations. In K. MacDonald & D. Pelligrini (Eds.), Parent-child play: Descriptions and Implications, (p. 259 – 286). New York: SUNY.
Fernald A, Taeschner T, Dunn J, Papousek M, de Boysson-Bardies B, Fukui I. 1989. A cross-language study of prosodic modifications in mothers’ and fathers’ speech to preverbal infants. J Child Lang. 1989.16(3):477-501.
Hampson J and Nelson K. 1993. The relation of maternal language to variation in rate and style of language acquisition. J Child Lang. 20(2):313-42.
Han M, DE Jong NH, Kager R. 2023. Relating the prosody of infant-directed speech to children’s vocabulary size. J Child Lang. 2023 Feb 9:1-17. Published online ahead of print.
Han M, De Jong NH, Kager R. 2022. Prosodic input and children’s word learning in infant- and adult-directed speech. Infant Behav Dev. 68:101728.
Hayashi A, Tamekawa Y, and Kiritani S. 2001. Developmental change in auditory preferences for speech stimuli in Japanese infants. Journal of Speech, Language, and Hearing Research, 44(6): 1189–1200.
Hilton CB, Moser CJ, Bertolo M, Lee-Rubin H, Amir D, Bainbridge CM, Simson J, Knox D, Glowacki L, Alemu E, Galbarczyk A, Jasienska G, Ross CT, Neff MB, Martin A, Cirelli LK, Trehub SE, Song J, Kim M, Schachner A, Vardy TA, Atkinson QD, Salenius A, Andelin J, Antfolk J, Madhivanan P, Siddaiah A, Placek CD, Salali GD, Keestra S, Singh M, Collins SA, Patton JQ, Scaff C, Stieglitz J, Cutipa SC, Moya C, Sagar RR, Anyawire M, Mabulla A, Wood BM, Krasnow MM, Mehr SA. 2022. Acoustic regularities in infant-directed speech and song across cultures. Nat Hum Behav. 6(11):1545-1556.
Jacobson JL, Boersma DC, Fields RB and Olson KL. 1983 Paralinguistic Features of Adult Speech to Infants and Small Children. Child development 54: 436-442.
Kalashnikova M, Carignan C, Burnham D. 2017. The origins of babytalk: smiling, teaching or social convergence? R Soc Open Sci. 4(8):170306.
Kalashnikova M, Peter V, Di Liberto GM, Lalor EC, Burnham D. 2018. Infant-directed speech facilitates seven-month-old infants’ cortical tracking of speech. Sci Rep. 8(1):13745
Kao C, Sera MD, Zhang Y. 2022. Emotional Speech Processing in 3- to 12-Month-Old Infants: Influences of Emotion Categories and Acoustic Parameters. J Speech Lang Hear Res. 65(2):487-500.
Kaplan PS, Sliter JK, and Burgess AP. 2007.Infant-directed speech produced by fathers with symptoms of depression: effects on infant associative learning in a conditioned-attention paradigm. Infant Behav Dev. 30(4):535-45.
Kelkar A. 1965. Marathi baby talk. Word 20: 40-54.
Kemler-Nelson DG, Hirsh-Pasek K, Jusczyk PW, Cassidy KW. 1989. How the prosodic cues in motherese might assist language learning. J Child Lang. 16(1):55-68.
Koda H and Masataka N. 2002. A pattern of common acoustic modification by human mothers to gain attention of a child and by macaques of others in their group. Psychol Rep. 91(2):421-2.
Laughren M. 1984. Warlpiri baby talk. Australian Journal of Linguistics 4(1): 73-88.
Masapollo M, Polka L, Ménard L. 2016. When infants talk, infants listen: pre-babbling infants prefer listening to speech with infant vocal properties. Dev Sci. 19(2):318-28.
Meegaskumbura PB. 1980. Tondol: Sinhala baby talk. Word, 31(3), 287-309.
Menn KH, Michel C, Meyer L, Hoehl S, Männel C. 2022. Natural infant-directed speech facilitates neural tracking of prosody. Neuroimage. 251:118991.
Mitchell, R.W. 2001. Americans’ talk to dogs: Similarities and differences with talk to infants. Research on Language and Social Interaction, 34(2), 183-210.
Monnot M. 1998. Function of infant-directed speech. Human Nature 10(4): 1045-6767.
Niwano K and Sugai K. 2003. Maternal accommodation in infant-directed speech during mother’s and twin-infants’ vocal interactions. Psychol Rep. 92(2):481-7.
Piazza EA, Iordan MC, Lew-Williams C. 2017. Mothers Consistently Alter Their Unique Vocal Fingerprints When Communicating with Infants. Curr Biol. 27(20):3162-3167.e3.
Polka L, Masapollo M, Ménard L. 2022. Setting the Stage for Speech Production: Infants Prefer Listening to Speech Sounds With Infant Vocal Resonances. J Speech Lang Hear Res. 65(1):109-120.
Räsänen O, Kakouros S, Soderstrom M. 2018. Is infant-directed speech interesting because it is surprising? – Linking properties of IDS to statistical learning and attention at the prosodic level. Cognition. 178:193-206.
Ratner NB and Pye C. 1984. Higher pitch in BT is not universal: acoustic evidence from Quiche Mayan. J Child Lang. 11(3):515-22.
Ramírez-Esparza N, García-Sierra A, Kuhl PK. 2017. Look Who’s Talking NOW! Parentese Speech, Social Context, and Language Development Across Time. Front Psychol. 8:1008.
Saint-Georges C, Chetouani M, Cassel R, Apicella F, Mahdhaoui A, Muratori F, Laznik MC, Cohen D. 2013. Motherese in interaction: at the cross-road of emotion and cognition? (A systematic review). PLoS One. 8(10):e78103.
Saito Y, Aoyama S, Kondo T, Fukumoto R, Konishi N, Nakamura K, Kobayashi M, and Toshima T. 2007. Frontal cerebral blood flow change associated with infant-directed speech. Arch Dis Child Fetal Neonatal Ed. 92(2):F113-6.
Schachner A and Hannon EE. 2011. Infant-directed speech drives social preferences in 5-month-old infants. Dev Psychol. 47(1):19-25.
Schick J, Fryns C, Wegdell F, Laporte M, Zuberbühler K, van Schaik CP, Townsend SW, Stoll S. 2022. The function and evolution of child-directed communication. PLoS Biol. 20(5):e3001630.
Shieffelin B and Ochs E. 1996. The microgenesis of competence: Methodology of language socialization. In D.I. Slobin, J. Gerhardt, A. Kyratziz, and J. Guo (eds.): Social interaction, social context and language: Essays in honor of Susan Ervin-Tripp. Lawrence Erlbaum Associates, pp.251-264.
Spinelli M, Fasolo M, Mesman J. 2017. Does prosody make the difference? A meta-analysis on relations between prosodic aspects of infant-directed speech and infant outcomes. Dev. Rev. 44: 1-18.
Sulpizio S, Kuroda K, Dalsasso M, Asakawa T, Bornstein MH, Doi H, Esposito G, Shinohara K. 2017. Discriminating between mothers’ infant- and adult-directed speech: Cross-linguistic generalizability from Japanese to Italian and German. Neurosci Res. pii: S0168-0102(17)30166-9.
Swanson LA and Leonard LB. 1994. Duration of function-word vowels in mothers’ speech to young children. J Speech Hear Res 37: 1394-1405.
Thiessen ED, Hill EA and Saffran JR. 2005. Infant-directed speech facilitates word segmentation. Infancy 1(1): 53-71.
Trainor LJ, Austin CM, Desjardins RN. 2000. Is infant-directed speech prosody a result of the vocal expression of emotion? Psychol Sci. 11(3):188-95.
Werker JF, Pegg JE, and McLeod PJ. 1994. A cross-language investigation of infant preference for infant-directed communication. Infant behavior and development. 17: 323-333.
Zangl and Mills. 2007. Increased Brain Activity to Infant-Directed Speech in 6- and 13-Month-Old Infants. Infancy 11: 1 – 62.
Photo credits for “Baby Communication”:
image of mother and baby in park, talking on the grass, by TeodorLazarev / shutterstock
Content of “Baby Communication” last modified 4/2023
Portions of this text derive from an earlier version of the article, written by the same author.