ABSTRACT
Many studies have addressed the effect of neighborhood density (phonological similarity among words) on word learning in quiet listening conditions. We explored how noise influences the effect of neighborhood density on children's word learning. One-hundred-and-two preschoolers learned nonwords varied in neighborhood density in one of four listening conditions: quiet, +15 dB signal-to-noise ratio (SNR), +6 dB SNR, and 0 dB SNR. Results showed that a high-density advantage for children under quiet listening condition was significantly reduced as noise increased. This finding implies an adverse impact of noise on long-term outcomes of word learning.
Subject(s)
Learning , Noise , Speech Perception , Auditory Perception , Child, Preschool , Female , Humans , Linguistics , Male , Signal-To-Noise RatioABSTRACT
Purpose: Noisy conditions make auditory processing difficult. This study explores whether noisy conditions influence the effects of phonotactic probability (the likelihood of occurrence of a sound sequence) and neighborhood density (phonological similarity among words) on adults' word learning. Method: Fifty-eight adults learned nonwords varying in phonotactic probability and neighborhood density in either an unfavorable (0-dB signal-to-noise ratio [SNR]) or a favorable (+8-dB SNR) listening condition. Word learning was assessed using a picture naming task by scoring the proportion of phonemes named correctly. Results: The unfavorable 0-dB SNR condition showed a significant interaction between phonotactic probability and neighborhood density in the absence of main effects. In particular, adults learned more words when phonotactic probability and neighborhood density were both low or both high. The +8-dB SNR condition did not show this interaction. These results are inconsistent with those from a prior adult word learning study conducted under quiet listening conditions that showed main effects of word characteristics. Conclusions: As the listening condition worsens, adult word learning benefits from a convergence of phonotactic probability and neighborhood density. Clinical implications are discussed for potential populations who experience difficulty with auditory perception or processing, making them more vulnerable to noise.
Subject(s)
Phonetics , Probability , Verbal Learning , Vocabulary , Adult , Female , Humans , Learning , Male , Speech PerceptionABSTRACT
The goal of this study was to explore the effects of phonotactic probability, word length, word frequency, and neighborhood density on the words known by children with cochlear implants (CIs) varying in vocabulary outcomes in a retrospective analysis of a subset of data from a longitudinal study of hearing loss. Generalized linear mixed modeling was used to examine the effects of these word characteristics at 3 time points: preimplant, postimplant, and longitudinal follow-up. Results showed a robust effect of neighborhood density across group and time, whereas the effect of frequency varied by time. Significant effects of phonotactic probability or word length were not detected. Taken together, these findings suggest that children with CIs may be able to use spoken language structure in a manner similar to their normal hearing counterparts, despite the differences in the quality of the input. The differences in the effects of phonotactic probability and word length imply a difficulty in initiating word learning and limited working memory ability in children with CIs.
