Speech Perception Laboratory
Department of Speech
and Hearing Sciences, Indiana University
Children's perception of foreign-accented speech
In the real world, children hear speech that contains an enormous
amount of variability. Variability in speech includes factors such
as a talker’s dialect, gender, native language, age, and
emotional state. However, language acquisition, performance in school,
and social interactions all require the ability to compensate for this
substantial variability. The long-term goal of the research in the lab
is to increase our understanding of how children develop the ability to
accurately understand the speech of talkers that can sound very
different from one another and can sound radically different from the
child's own speech. We are focusing on the variability introduced by
differences in native language background of the talker. As one in five
people in the US speaks a language other than English at home,
foreign-accented speech represents an extremely common, real-world
source of speech variability. To understand a foreign-accented word,
listeners need to map a potentially novel, unfamiliar production of a
word to their own internal representation of the word. We are planning
to test how children perceive foreign-accented speech compared to
native-accented speech and to assess the cognitive-linguistic skills
that may underlie the ability to compensate for variability. We will
test such factors as vocabulary knowledge (are children who know more
words better at perceiving foreign-accented speech?) and phonological
memory (are children with better short-term memory abilities better at
perceiving foreign-accented speech?).
Database
We are currently developing a database of audio recordings of native
and non-native speakers of English. The database has 28 speakers
including four speakers each (2 females) from the following language
backgrounds: English, Spanish, German, French, Mandarin, Japanese, and
Korean. The speakers in this database were recorded reading words,
sentences, and paragraphs in English that
are appropriate for testing children. Each word, sentence or paragraph
has been segmented into an individual wave file. Additionally, we have
perceptual data regarding the intelligibility of all the words in the
database. We are currently working on phonetically transcribing all the
words in the database and obtaining intelligibility scores for all the sentences in the database.
This database will be made
publicly available and we anticipate will be useful to a wide
range of teachers, researchers, and clinicians for such purposes as the
assessment of speech, language and hearing problems, intervention for
children and adults with speech and language disorders, training of
English as a Second Language (ESL) teachers, and research on the
perception of foreign-accented speech by adults and children with and
without speech and language disorders or hearing loss.
Clinical applications
Although speech in the real world is highly variable, much experimental
and clinical testing of children has been conducted with
low-variability tasks (e.g., one talker with a "general American"
dialect). Children may do well on these standard hearing or speech
perception assessments, but may have difficulty with everyday
communication. Children with hearing loss are one population who may
have difficulty in understanding high variability speech. Testing how
these children perform on speech perception tests that include
foreign-accented speech, a frequent source of variability, will more
closely simulate real world situations. Thus, these tests will provide
more accurate measures of children's performance outside the clinic or
research laboratory.
Available equipment
- Handheld microphone (Sennheiser E845s Dynamic Supercardioid)
- Headset microphone (Shure Dynamic WH20XLR)
- Digital recorder (Marantz PDM670)
- Five PC based computers for data entry, data analysis, acoustic analysis, statistical analysis, sound file segmentation, etc.
- Eight sets of headphones (4 - Sony MDR7506; 4 - Sennheiser HD280 Pro)
- Four Mac Minis used for perceptual testing