PSY393 Essay: Infant-Directed Speech (IDS) vs Adult-Directed Speech

This essay explores the impact of infant-directed speech (IDS) compared to adult-directed speech (ADS) on language acquisition in infants. It delves into the characteristics of both speech styles, highlighting that IDS, with its higher pitch, simpler sentences, and slower pace, is often preferred by infants. The essay discusses how IDS aids in capturing attention, facilitating word segmentation, and promoting cognitive development. It also evaluates evidence from various studies, including research on prosodic cues and the influence of IDS on the perception of multisensory gender coherence. The essay concludes that infants learn language more effectively from IDS due to its tailored features, which support their social and cognitive development, while also acknowledging some potential limitations in its role in certain aspects of infant perception.

Running head: PSYCHOLOGY: THE DEVELOPING MIND
Psychology: The Developing Mind
Name of the Student:
Name of the University:
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1PSYCHOLOGY: THE DEVELOPING MIND
The early multisensory perceptual experiences of children shape their abilities of
performing the socially-relevant visual categorisation like that of the extraction of emotion,
age, and gender from the faces. The language acquisition of infants proceeds at an amazing
speed despite the inherent difficulties in the process of discovering some linguistic units like
words and phonemes from a continuous speech. Interactions with infants often involve a
different style of speaking (Richoz et al., 2017). During interacting with them, their
caregivers typically adopt a very unique speech register. It is referred to as the infant-direct
speech. It is different from the register that is used in the exchanges or interactions between
adults, which is known as adult-directed speech. Notwithstanding this fact, there has been
very little known regarding the role or importance of infant-direct speech in the processing of
rhythmic structures among the infants. This paper shall elaborate on presenting an essay
discussing whether infants learn language better from the infant-direct speech (IDS) than
from the adult-direct speech (ADS). It shall also highlight the different elements of IDS that
are proposed to be helpful in such scenarios and would evaluate the available evidences on
the same.
Infant-direct speech (IDS) and its characteristics
During birth, infants are able to differentiate between the rhythms of their native
language. In the first year of life, they get attune to the different sounds that they hear of their
native language and during the second year of their life, they start to produce some of their
first words. IDS refers to the speech register that adults make use of while addressing the
young infants (Hartman, Ratner & Newman, 2017). It is to mention that IDS is characterised
by wider range of pitch, simpler sentences, longer pauses, shorter utterances, higher pitch and
slower rate of speaking. According to many researchers, IDS plays a critical part in the
regulation of the interaction in between infant and the caregiver and at the same time, in the
assistance of cognitive, language and speech development (Lee et al., 2014). Richoz et al.

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(2017) too have claimed that IDS is characterised by shorter utterances, better articulation,
higher pitch, longer pauses and slower tempo. It is a very powerful tool that parents use
instinctively for aiding the language development during the first months of the infants and
their years of life. Walle and Campos (2014) have suggested that it was only once that the
human language emerged that IDS acquired a second purpose- facilitating the language
learning among infants.
Adult-direct speech (ADS) and its characteristics
ADS on the other hand refer to the speech register that is characterised by narrow
range of pitch, complicated sentences, shorter pauses, longer utterances, faster rate of
speaking and lower pitch. It is completely the opposite of IDS that is characterised by high-
pitched voices. In other words, it is the register that is used in the adult to adult exchanges.
According to Richoz et al. (2017), the normal fundamental frequency of male voice differs
from 90 to 140 Hz, while that of a female one is between 170 Hz to 290 Hz for the ADS. On
the other hand, for the IDS, this frequency range from 120 to 190 Hz for the voices of males
and it is 250 to 450 Hz for that of females. It is this higher pitches in the IDS that bring the
voices of the male closer to the usual day to day frequencies of the female Ads that have the
possibility of creating some possible basis for why the younger infants face more difficulty in
matching the gender when they are presented with an IDS utterance that is corresponding to
the face of the female or male.
IDS over ADS
It is to mention that the manner of speech, be it infant direct or adult directed,
influenced the perception of the multisensory gender coherence. In day to day life, siblings or
parents interact with the children by means of using the infant-direct speech (IDS), which
further varies at both the linguistic and prosodic levels (Goncalves, Cardoso-Martins &

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Echols, 2016). It is to note that the melodic contours and the exaggerated prosodic features of
the IDS are known to present the language-independent sources of details and information
that reflect the global parental behaviour- to express the positive impact of the caregivers and
to maintain the attention of the infants. With the same, the typically-developing infants are
very sensitive to the different prosodic properties in the speech and they usually prefer IDS
over the ADS as it is characterised by higher pitch, usage of special words, slower rhythm,
better articulation and many breaks.
As compared to the ADS, it has been argued that IDS is very effective for attracting
and holding the attention of the infants. It is linked with high level of social responsiveness
than that of the ADS (Li, Huang & Bente, 2016). With the same, it is also to mention that one
might expect that high level of attention is likely to result in stronger perception of the multi-
sensory gender coherence among the infants. Notwithstanding this fact, as the IDS promote
language acquisition and learning among infants. Furthermore, it is also worth noting that one
did not observe any differences in between the ADS and the IDS conditions for the infants
belonging from the age range of nine to twelve years old.
There are many studies that have concluded that the type or manner of speech has a
great impact on the social and cognitive development of the infants. IDS promote the
language acquisition, lexical comprehension and the word segmentation knowledge among
the infants (Morningstar et al., 2019). On the basis of the earlier evidence, it can be reasoned
that the IDS might also ease the removal of the gender information right from voice and face.
Notwithstanding this fact, even though IDS is known to ease the word segmentation and the
lexical learning, its easing role in the perceiving of the multisensory gender coherence may
be non-existent or minimal. Furthermore, according to Walle and Campos (2014), the high
pitch of the IDS that brings the voices of the male closer to the regular frequencies of the

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voices of female, even impede the potential of the infants to perceive some multisensory
gender coherence.
In the study conducted by Marno et al. (2015), it has been discovered that six month
old infants were much more attracted towards their own patterns of speech as compared to
those of the adults. In the study, the infants listened to repeating vowel sound that mimicked
the ones that made by a women or those by an infant using synthesis tool. On an average, the
infants in the study listened to the vowels of a fellow baby about 40% longer than that of the
vowels of the adult women. It is very important to mention that according to Galazka et al.
(2014) too, “infant-like vowel sounds that they heard were not yet part of their everyday
listening experience”. This means that the infants were not partial to their own type of simply
out of the familiarity. Knowing about the speech preferences of the infant can help in
designing more effective tools for the development and improvement of their speech. IDS is
one among them. It is a very powerful tool that parents use instinctively for aiding the
language development during the first months of the infants and their years of life. According
to many researchers, infants respond greatly to the high-pitched voices.
Another study conducted by Gergely et al. (2017) revealed that infants reacted
productively and positively to the voices of their mothers when they spoke in higher pitch
than in normal one. This means- the infant-directed speech, that is, unlike ADS, characterised
by higher pitch, simpler sentences, longer pauses, shorter utterances and slower rate of
speaking. The authors have also theorised that infants help in guiding their parents by means
of providing positive and productive feedback when they like what they hear. Similar to
listening to the other infants, the IDS aids in keeping the attention of the infants. The reason
behind this as suggested by Laing, Vihman and Keren-Portnoy (2017) is that perhaps when
adults use a high pitched voice for speaking with the infants, they actually tend to prepare
them to perceive their own voices. Studies demonstrated that when infants babble among

5PSYCHOLOGY: THE DEVELOPING MIND
themselves, they do not just babble, they in fact communicate with one another. The higher
pitch of the IDS has the possibility of affecting the perception of the multisensory gender
coherence in the infants.
Many researchers are also of the opinion that IDS ease the process of word learning
among the infants. There are many reasons why IDS might facilitate the word learning. The
most obvious perhaps has to do with the familiarity when infants are addressed directly; it is
more often in the IDS than it is in the ADS. According to Petrone et al. (2017), prosodic cues
like that of intonation, pre-boundary lengthening and pausing are very important for the
segmentation of speech among the four to six months infants who learn English. Perhaps,
children readily encode the phonological details and information from the IDS as compared
to the ADS and it is likely to be due to the fact that IDS involve expanded vowel space. On
the basis of the earlier evidence, it can be reasoned that the IDS might also ease the removal
of the gender information right from voice and face. Notwithstanding this fact, even though
IDS is known to ease the word segmentation and the lexical learning, its easing role in the
perceiving of the multisensory gender coherence may be non-existent or minimal.
Elements of IDS
IDS is characterised by wider range of pitch, simpler sentences, longer pauses, shorter
utterances, higher pitch and slower rate of speaking. Its main purpose is to capture the
attention of the infants and make it easier for them to grasp to acquire the emotional
intentions of the speech that they hear (Narayan & McDermott, 2016). It is to mention that
the IDS comprises of several modifications that seem to be tailor made for the learners of
language (infants). It is slower, more repetitive than ADS and is more likely to exaggerate the
pronunciation of the vowels. With the same, it is also to mention that people who make use of

6PSYCHOLOGY: THE DEVELOPING MIND
IDS are more likely speak in simpler and shorter utterances. Research studies suggest that all
these modifications help in developing the key abilities among the infants and they include:
a) The ability of discriminating the different types of speech sounds.
b) The ability of detecting the boundaries prevailing in between different words in a long
stream of speech.
c) The ability of recognising the different clauses in a stream of speech.
It is even possible that the individual differences in the way in which parents make use of
IDS an influence how quickly the infants learn speaking. IDS also help the infants in tuning
into the sounds of their native language () and at the same it, it also makes it easier for the
infants to learn about different words, which is a key problem for any language learner.
Hence, it is to conclude that infants do learn language better from IDS compared to
ADS. The elements like the high pitch voice, simpler sentences, longer pauses, shorter
utterances and slower rate of speaking in IDS compared to ADS are proposed to be helpful
for the infants in their social and cognitive development. A range of studies have provided
detailed evidences on the same. There are many differences in between the ADS and IDS that
aid to the developmentally earlier matching of the visible and the audible cues among the
infants who are listening to the ADS. The evidences and studies demonstrated that the IDS
tool influence the cognitive development of the infants while promoting the language
acquisition, word recognition, word segmentation in the sentences and lexical
comprehension. All these characteristics suggest that IDS ease all the different aspects of
language acquisition.

7PSYCHOLOGY: THE DEVELOPING MIND
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