Speech sound confusions in wellperforming adults and children with cochlear implants, measured by repetition of mono- and bisyllabic nonsense words

Abstract

This PhD project aimed to investigate typical consonant and vowel confusions in well-performing, pre- and postlingually deaf children and adults with cochlear implants (CIs), and compare this data to reference groups of normal-hearing children and adults. Consonants and vowels were presented in the context of mono- and bisyllabic nonsense words in a nonsense syllable repetition test. The mainly prelingually deaf children with CIs obtained overall higher scores than the mainly postlingually deaf adult CI users on the tests. For both groups, consonants were mostly confused with consonants with the same voicing and manner. Voiced consonants were less well perceived than unvoiced consonants, and there was a devoicing bias for the stops. A high confusion rate of nasals with other nasals was revealed, and [y:] was perceived as [i:] twice as often as [y:] was repeated correctly. The study outcomes indicate that there still are limitations in today’s CI technology for the transmission of low-frequency sounds and may be useful for the development of new CI technology. The outcomes may also be useful for CI programming and for planning of auditory training and speech therapy for implantees.