Speech-evoked cortical potentials recognition in cochlear implant users and speech

Abstract

Processing in the auditory cortex may play a role in the unexplained variability in cochlear implant benefit. P300 and N1/P2 were elicited in post-lingually deaf cochlear implant users wearing a Nucleus multichannel cochlear implant. Four sound contrasts were presented (500-1,000 Hz, /ba/-/da/, /ba/-/pa/ and /i/-/a/). N1 and P2 were present in all subjects for all conditions. Prolonged N1, P2 and P300 latencies were found in the cochlear implant group compared to a control group of subjects with normal hearing. Cochlear implant users show smaller amplitudes of N1 for all the speech signals as well as smaller amplitudes of P2 for the consonants compared to the controls. P300 results of the cochlear implant users were compared to behavioural results of speech recognition testing. A relation was found between P300 amplitude and magnitude for the 500-1,000 Hz and /i/-/a/ contrasts and behavioural speech recognition in cochlear implant users. The results suggest that P300 measurements are useful and have additional value to speech recognition evaluations in cochlear implant users.

On the relationship between auditory cognition and speech intelligibility in cochlear implant users: An ERP study

“…In contrast to previous studies (Beynon et al, 2005;Groenen et al, 2009), our participants could not rely on perceptual discrimination alone but had to identify the meaning of the two-syllabic words. Our results revealed poorer speech intelligibility in CI users than in NH listeners and group-specific modulation effects of ERPs as a function of background noise.…”

“…Central auditory and cognitive processing in CI users has been usually examined by means of the oddball paradigm (Beynon et al, 2005;Groenen et al, 2009;Henkin et al, 2009). Here, the participants are presented with infrequent stimuli deviating in some physical or higher-order feature from regular standard sounds (Donchin and Coles, 1998;Polich, 2007).…”

“…Despite providing important insights into central auditory processing, most of the EEG studies with CI users have been limited in that they used simple stimuli such as tones and syllables (Beynon et al, 2005;Groenen et al, 2009;Okusa et al, 1999;Soshi et al, 2014). More complex stimuli have been used only recently in a study with a limited stimulus set consisting of two words (Henkin et al, 2014).…”

Cortical Neural Activity Underlying Speech Perception in Postlingual Adult Cochlear Implant Recipients

“…The potentials were elicited by pairs of stimuli, that differed by a vowel contrast (/da/ vs. /di/) [Micco et al, 1995] or by a consonant contrast (/da/ vs. /ta/) [Kraus et al, 1993]. Groenen et al [2001] and Beynon et al [2005] recorded the P3 potential in adult CI recipients and showed that while a vowel discrimination task (/i/ vs. /a/) elicited P3 potentials similar to those of NH subjects, consonant discrimination tasks (/ba/ vs. /pa/, /ba/ vs. /da/) yielded a smaller, prolonged, or absent P3. The fact that P3 of CI recipients was similar to that recorded from NH subjects in the easier vowel discrimination task suggests that these stimuli may not be sensitive to the differences in central auditory processing between the two groups.…”

The Effects of Noise on Auditory Cortical P300 Potential in Normal Hearing People

“…4,5 Kortekste bilinç seviyesinde oluşan bu potansiyel, dikkat, hafıza gibi bilişsel fonksiyonlardan etkilenmektedir. 6,7 Üst seviyede bilişsel işlemi yansıtan P300 yanıtı, normal işiten ve işitme cihazı/koklear implant kullanan kişilerin işitsel hafıza, işitsel ayırt etme becerilerinin ve konuşma performanslarının değerlendirilmesinde önemli bir yer tutmaktadır. 8 Odyolojide, farklı "sinyal/gürültü oran (SGO)'larında farklı tipte gürültü verilerek santral işitme sisteminin fonksiyonları değerlendirilmek-tedir.…”