Speech timing and working memory in profoundly deaf children after cochlear implantation

Abstract

Thirty-seven profoundly deaf children between 8-and 9-years-old with cochlear implants and a comparison group of normal-hearing children were studied to measure speaking rates, digit spans, and speech timing during digit span recall. The deaf children displayed longer sentence durations and pauses during recall and shorter digit spans compared to the normal-hearing children. Articulation rates, measured from sentence durations, were strongly correlated with immediate memory span in both normal-hearing and deaf children, indicating that both slower subvocal rehearsal and scanning processes may be factors that contribute to the deaf children's shorter digit spans. These findings demonstrate that subvocal verbal rehearsal speed and memory scanning processes are not only dependent on chronological age as suggested in earlier research by Cowan and colleagues (1998). Instead, in this clinical population the absence of early auditory experience and phonological processing activities before implantation appears to produce measurable effects on the working memory processes that rely on verbal rehearsal and serial scanning of phonological information in short-term memory.

Relationship between Working Memory, Auditory Perception and Speech Intelligibility in Cochlear Implanted Children of Elementary School

“…Also, there was a positive and significant relationship between speech intelligibility and working and short-term memories of cochlear-implanted children. These findings are compatible with the results of Ibertson et al [10], Philips et al [12], Dawson et al [13], and Burkhoder et al [17]. It can be said that although the growth levels of auditory skills in cochlearimplanted children are different, there is a background for creation of production patterns.…”

Speech Perception in Deaf Children with Cochlear Implants

“…In addition to our recent studies on verbal rehearsal speed, we have also obtained several new measures of memory scanning during the digit recall task from a group of deaf children with cochlear implants and a group of typically-developing age-matched normal-hearing children (see Burkholder & Pisoni, 2003). Our interest in studying speech timing in these children was motivated by several recent findings reported by Cowan and his colleagues who have carefully measured the response latencies and interword durations during recall tasks in children of different ages.…”

“…Recently, we obtained several measures of speech-timing during immediate recall from a group of deaf children who use cochlear implants (see Burkholder & Pisoni, 2003). Measures of speaking rate and speech timing were also obtained from an age-matched control group of normal-hearing, typically developing children.…”

“…The effects of early auditory and linguistic experience found by Burkholder and Pisoni (2003) suggest that the development of subvocal verbal rehearsal and serial scanning processes may not only be related to maturationally-based milestones that are cognitively or metacognitively centered, such as the ability to effectively organize and utilize these two processes in tasks requiring immediate recall. Rather, efficient subvocal verbal rehearsal strategies and scanning abilities also appear to be experience-and activity-dependent reflecting the development of neural mechanisms used in speech perception and speech production.…”

“…Because the group of deaf children examined in the Burkholder and Pisoni (2003) study fell within a normal range of intelligence, the most likely developmental factor responsible for producing slower verbal rehearsal speeds, scanning rates, and shorter digit spans is an early period of auditory and linguistic deprivation prior to receiving a cochlear implant. Sensory deprivation may result in widespread developmental brain plasticity and neural reorganization, further differentiating deaf children's perceptual and cognitive development from the development of normal-hearing children (Kaas, Merzenich & Killackey, 1983;Shepard & Hardie, 2001).…”