perception of accents and dialects in adults and infants

54 Pages·2014·1.68 MB·English

Joseph Butler
University of Plymouth, UK
PhD thesis
Why accents?


Aims

◦ Examine how our perceptual system processes and
adapts to accents and dialects
◦ Try to understand the developmental origins of
these processes
Infants primary task is to learn the sound system

of their native language

Between birth and the end of the 1st year, infants

move from a universal phonetic sensitivity (e.g.,
Trehub, 1976; Eimas et al., 1971) to the
acquisition of language-specific phonetic
contrasts (e.g., Werker & Tees, 1984; Kuhl et al.,
1992)

Variability is a challenge for infants in the first

year of life
◦ Gender, speaking rate, affect, accent
Infants have been shown to be sensitive to, and able to

adapt to, talker variability in the speech signal

As young as 2 months old, infants are able to deal with

talker variability to a certain extent
◦ Jusczyk et al. (1992) – infants able to detect a change in syllable
across multiple speakers as along as there is no delay between
habituation and testing

Infants at 6 months are able to recognise invariant

acoustic properties of vowel categories across different
speakers and pitch variations (Kuhl et al., 1979)

At 2, 3 and 6 months, infants are able to ignore a change

in speaker if not acompanied by a change in vowel as well
(Marean et al., 1992)
Gender

◦ Infants at 7.5 months only able to segment
continuous speech across speakers of the same
gender, only able to segment across gender at 10.5
months (Houston & Jusczyk, 2000)
Affect

◦ Infants only able to segment across affect at 10.5
months, not at 7.5 months (Singh et al., 2004)
◦ However, when presented with multiple affect
types, infants at 7.5 months displayed more mature
word recognition abilities (Singh, 2008)
What do infants know about languages?


Infants are able to discriminate between languages at birth, if their

native language is present (Melher et al., 1988 – but see Melher &
Christophe (1995) that suggests infants can discriminate regardless of
whether the native language is present or not)

Infants at 5 months can discriminate between languages if they are from

different rhythmic classes (British English vs. Japanese; Italian vs.
Japanese) or within, if their own language was present (British English vs.
Dutch; American English vs. British English), but not within a rhythmic
class if both languages were unfamiliar (German vs. Dutch; Italian vs.
Spanish) – Nazzi et al., 2000

Experience of the native language alters infants phonetic perception –

able to generalise across variations within their own language but not in
an unfamiliar language (Kuhl et al., 1992)

Infants are able to perceive differences between language, and use this

to guide social behaviours, throughout development (Kinzler et al.,
2007)
What do infants know about accents.

◦ Kitamura, Panneton, Notley, & Best (2006)
 Investigated Australian learning and American English
learning infants’ abilities to discriminate these language
 At 6 months, American learning infants showed preference
for their own language, no preference found for Australian
learning infants at 6 months, but there was at 3 months

◦ Diehl, Varga, Panneton, Burnham, & Kitamura (2006)
 Looked at American learning infants preference for native vs.
non-native language sounds
 Infants at 6 months, but not at 8 months, showed a
preference for the native over the non-native (Australian)
language sounds
Extend previous findings to a new population

◦ Infants from the South West of England

Effect of familiarity of the accent


Does accent discrimination ability decline?

HeadTurn Preference Procedure

◦ Used in previous studies looking at infant speech
discrimination (e.g., Nazzi et al., 2000)
Stimuli used was the same as that used in

Nazzi et al. (2000)

Recorded using speakers from:

◦ Plymouth (native accent)
◦ Wales (non-native regional accent)
◦ Scotland (non-native regional accent)

Child directed speech
