Author: David B. Pisoni, Mario Svirsky, Karen I. Kirk, and Richard T. Miyamoto
Abstract:
It is now well-established in the field of pediatric cochlear
implantation that some prelingually deaf children perform significantly
better on standardized tests of speech perception and spoken word
recognition than other prelingually deaf children. The differences are
seen most clearly on very difficult open-set tests of spoken word
recognition such as the PBK test. The children who do well on this
particular test are frequently referred to as the "Stars," and their
extraordinarily good performance is typically reported at scientific
meetings and highlighted in journal publications. Unfortunately, very
little is actually known about the basis for the superior performance of
these children or the audiological and psychological factors that
predict which children will become "Stars" and which ones will perform
closer to the mean. In this paper, we report the initial results of a
correlational analysis of a small group of exceptionally good cochlear
implant users, the so-called "Stars." Our goal was to identify the
primary factors that underlie their exceptionally good performance on
open-set tests of speech perception and spoken word recognition. Speech
perception, intelligibility and language scores were examined for a
group of children who scored in the top 20% on the PBK test two years
post-implant and a "control" group of children who scored in the bottom
20% on the PBK test. Separate correlational analyses were then carried
out on the test scores for these subjects 1 year post-implant in order
to examine the relations among these dependent measures. The results of
our analyses revealed that the "Stars" not only display superior
performance on the criterial PBK test but also show very high levels of
performance on several other speech perception and language tests. Most
notable were the unusually high correlations among several different
measures of spoken word recognition and scores on the Reynell receptive
and expressive language scales. This suggests that one common underlying
factor in these children may be the acquisition of language,
specifically, the development of the lexicon, which serves as the
"interface" between the initial sensory input and the phonological
representation of the sound patterns of words in lexical memory. In
addition, word recognition performance was also highly correlated with
speech intelligibility scores and open-set measures of language
comprehension that required children to interpret spoken language in
meaningful ways. Taken together, our analyses of these exceptionally
good cochlear implant users suggest that the "Stars" are the children
who have been able to begin the normal process of language acquisition.
The pattern of intercorrelations among several measures of speech
perception, intelligibility, and language development suggests that
these children are receiving sufficient sound input through their
cochlear implants to map sound patterns onto meanings and build a
lexicon of words, two necessary prerequisites for constructing a grammar
of the target language from the ambient language spoken in their
environment.