Variation in speech perception scores among children with cochlear implants

OBJECTIVE: The objective of this study was to identify common factors affecting speech perception scores in children with cochlear implants. DESIGN: Speech perception data for 167 implanted children were collected at two cochlear implant centres in Melbourne and Sydney. The data comprised audition-alone scores on open-set word and sentence tests. Children were selected on the basis that they had a Nucleus 22-electrode cochlear implant. The average age of the children was 5 yr. Information was also collected about 12 factors that may have influenced speech perception scores for each child. Analysis of covariance was used to identify factors that significantly affected speech perception scores. Pearson pairwise correlation coefficients were also calculated for all factors analyzed. RESULTS: The analyses in this study identified factors that accounted for 51%, 34%, and 45% of the variance in phoneme, word and sentence perception scores. Scores decreased by 1.4 to 2.4% per year of profound deafness prior to implantation. Children who normally use oral communication scored significantly higher than children normally using sign or simultaneous oral and sign communication. Children implanted in Sydney scored higher on average than children implanted in Melbourne. CONCLUSIONS: The results show that a significant part of the variation in speech perception scores is systematically related to audiological and environmental factors for each child. The reasons for significant differences between children using different communication modes or from different clinics were not identified.     

Electrode discrimination and speech perception in young children using cochlear implants

OBJECTIVE: The aim was to determine the efficacy of a child-appropriate procedure to assess electrode discrimination ability in young children using cochlear implants and to investigate the relationship of electrode discrimination ability and speech perception performance in children implanted at a young age. DESIGN: An adaptation of the play audiometry procedure was used to assess electrode discrimination in seventeen 4- to 10-yr-old children. The children were required to respond with a game-like motor response when a repeating stimulation on a reference electrode "changed" to a different electrode. They were also assessed on a speech feature discrimination test, a closed-set word recognition test and a nonverbal intelligence task. RESULTS: Sixty-five percent of subjects demonstrated ability to discriminate adjacent electrodes in mid and apical regions of the cochlea, whilst the remaining subjects needed electrode separations of between two and nine electrodes for successful discrimination. In a forward stepwise regression analysis electrode discrimination ability was found to be the strongest factor in accounting for variance in the speech perception scores. Subject variables such as duration of deafness, nonverbal intelligence and implant experience did not significantly account for further variance in the speech perception scores for this group of children. CONCLUSIONS: Electrode discrimination ability was the strongest factor in predicting performance on speech perception measures in a group of children using cochlear implants.     

Psychoacoustic performance and music and speech perception in prelingually deafened children with cochlear implants

The number of pediatric cochlear implant (CI) recipients has increased substantially over the past 10 years, and it has become more important to understand the underlying mechanisms of the variable outcomes in this population. In this study, psychoacoustic measures of spectral-ripple and Schroeder-phase discrimination, the Clinical Assessment of Music Perception, and consonant-nucleus-consonant (CNC) word recognition in quiet and spondee reception threshold (SRT) in noise tests have been presented to 11 prelingually deafened CI users, aged 8-16 years with at least 5 years of CI experience. The children's performance was compared to the previously reported results of postlingually deafened adult CI users. The average spectral-ripple threshold (n = 10) was 2.08 ripples/octave. The average Schroeder-phase discrimination was 67.3% for 50 Hz and 56.5% for 200 Hz (n = 9). The Clinical Assessment of Music Perception test showed that the average complex pitch direction discrimination was 2.98 semitones. The mean melody score was at a chance level, and the mean timbre score was 34.1% correct. The mean CNC word recognition score was 68.6%, and the mean SRT in steady noise was -8.5 dB SNR. The children's spectral-ripple resolution, CNC word recognition, and SRT in noise performances were, within statistical bounds, the same as in a population of postlingually deafened adult CI users. However, Schroeder-phase discrimination and music perception were generally poorer than in the adults. It is possible then that this poorer performance seen in the children might be partly accounted for by the delayed maturation in their temporal processing ability, and because of this, the children's performance may have been driven more by their spectral sensitivity.     

Auditory, speech and language development in young children with cochlear implants compared with children with normal hearing

Objective

This study had two aims: (1) to document the auditory and lexical development of children who are deaf and received the first cochlear implant (CI) by the age of 16 months and the second CI by the age of 31 months and (2) to compare these children's results with those of children with normal hearing (NH).

Methods

This longitudinal study included five children with NH and five with sensorineural deafness. All children of the second group were observed for 36 months after the first fitting of the device (cochlear implant). The auditory development of the CI group was documented every 3 months up to the age of two years in hearing age and chronological age and for the NH group in chronological age. The language development of each NH child was assessed at 12, 18, 24 and 36 months of chronological age. Children with CIs were examined at the same age intervals at chronological and hearing age.

Results

In both groups, children showed individual patterns of auditory and language development. The children with CIs developed differently in the amount of receptive and expressive vocabulary compared with the NH control group. Three children in the CI group needed almost 6 months to make gains in speech development that were consistent with what would be expected for their chronological age. Overall, the receptive and expressive development in all children of the implanted group increased with their hearing age.

Conclusion

These results indicate that early identification and early implantation is advisable to give children with sensorineural hearing loss a realistic chance to develop satisfactory expressive and receptive vocabulary and also to develop stable phonological, morphological and syntactical skills for school life. On the basis of these longitudinal data, we will be able to develop new diagnostic tools that enable clinicians to assess child's progress in hearing and speech development.     

Language and speech perception of young children with bimodal fitting or bilateral cochlear implants

Abstract

Objectives

This paper compares language development and speech perception of children with bimodal fitting (a cochlear implant in one ear and a hearing aid in the opposite ear) or bilateral cochlear implantation.

Methods

Participants were children enrolled in the Longitudinal Outcomes of Children with Hearing Impairment study. Language development was assessed at 3 years of age using standardized tests. Speech perception was evaluated at 5 years of age. Speech was presented from a frontal loudspeaker, and babble noise was presented either from the front or from both sides.

Results

On average, there was no significant difference in language outcomes between 44 children with bimodal fitting and 49 children with bilateral cochlear implants; after controlling for a range of demographic variables. Earlier age at cochlear implant activation was associated with better outcomes. Speech perception in noise was not significantly different between children with bimodal fitting and those with bilateral cochlear implants. Compared to normal-hearing children, children with cochlear implants required a better signal-to-noise ratio to perform at the same level, but demonstrated spatial release from masking of a similar magnitude.

Conclusions

This population-based study found that language scores for children with bilateral implants were higher than those with bimodal fitting or those with unilateral implants, but neither reached significance level.     

Rate-of-processing ability in children using cochlear implants and its relevance to speech perception

The aim was to assess the ability of young children using cochlear implants to process a change in place of stimulation under conditions of shortened stimulus duration and shortened interstimulus interval. The study investigated whether or not this ability accounted for a significant amount of the variance in the speech performance of the children additional to the variance accounted for by electrode discrimination ability (measured in a previous study). An adaptation of the play audiometry procedure was used to assess 'rate-of-processing' ability in 17 children aged between 4 and 10 years. Initially the child was required to respond with a game-like motor response when a repeating stimulation on a reference electrode 'changed' to a different electrode in relatively 'slow' conditions. The child was then required to respond to the 'change', when the duration of the stimuli and the time interval between the stimuli were decreased. All but one of the children using cochlear implants scored significantly above chance for all conditions of stimulus duration and interstimulus interval assessed. That is, they were able to discriminate place pitch changes when these changes occurred more rapidly in time. A stepwise regression was computed to determine the relative contributions of a number of variables, including rate-of-processing ability, in accounting for variance in the children's speech perception performance (measured in a previous study). Rate-of-processing ability did not account for any variance additional to that accounted for by electrode discrimination ability, which was found to be the most significant predictor of speech perception performance for this group of children in the previous study.     

Rate-of-processing ability in children using cochlear implants and its relevance to speech perception

Abstract

The aim was to assess the ability of young children using cochlear implants to process a change in place of stimulation under conditions of shortened stimulus duration and shortened interstimulus interval. The study investigated whether or not this ability accounted for a significant amount of the variance in the speech performance of the children additional to the variance accounted for by electrode discrimination ability (measured in a previous study). An adaptation of the play audiometry procedure was used to assess ‘rate-of-processing’ ability in 17 children aged between 4 and 10 years. Initially the child was required to respond with a gamelike motor response when a repeating stimulation on a reference electrode ‘changed’ to a different electrode in relatively ‘slow’ conditions. The child was then required to respond to the ‘change’, when the duration of the stimuli and the time interval between the stimuli were decreased. All but one of the children using cochlear implants scored significantly above chance for all conditions of stimulus duration and interstimulus interval assessed. That is, they were able to discriminate place pitch changes when these changes occurred more rapidly in time. A stepwise regression was computed to determine the relative contributions of a number of variables, including rate-of-processing ability, in accounting for variance in the children's speech perception performance (measured in a previous study). Rate-of-processing ability did not account for any variance additional to that accounted for by electrode discrimination ability, which was found to be the most significant predictor of speech perception performance for this group of children in the previous study.     

Tone perception in Mandarin-speaking children with cochlear implants

Abstract

Objective: To evaluate the effects of implant age and duration of implantation on development of Mandarin tone perception in paediatric cochlear implant recipients. Design: Retrospective cross-sectional evaluation of tone perception, as assessed with the Mandarin Early Speech Perception test at 3, 6, 12, 24, 36 and 48 months after activation. Study sample: A total of 143 subjects, 60 girls and 83 boys unilaterally implanted at 1–4 years of age comprised the sample. All the subjects were implanted with devices from one of three manufacturers. Results: Regardless of implant age, approximately 80% of the subjects obtained overall tone discrimination scores significantly above chance by 4 years after implantation, and average discrimination accuracy increased from approximately 68% to 79%. Acoustically distinct tones 1 and 4 were discriminated and recognised more accurately, while less distinct tones 2 and 3 were discriminated and recognised less accurately. Large individual differences in performance were evident. Conclusions: Most Mandarin-speaking paediatric CI recipients discriminate tones above chance at 5 years of age with accuracy comparable to that of children with normal hearing at 2 years of age. Modest benefits of early implantation are evident.     

Auditory cortical activation and speech perception in cochlear implant users

Cochlear implantation is generally accepted as a successful means of restoring auditory sensation to profoundly deaf individuals. Although most patients can expect a satisfactory outcome following implantation, some have poor speech perception outcomes. This investigation used [18F]-fluorodeoxyglucose positron emission tomography to measure cortical activity resulting from auditory stimulation in seven 'good' and four 'poor' cochlear implant recipients. Activations were significantly greater in both the primary and association cortices in the good compared with the poor implant users. We suggest that the ability to access the more specialised speech processing abilities of the auditory association cortices helps determine outcome following cochlear implantation.     

The effect of pre-operative developmental delays on the speech perception of children with cochlear implants

Objective

The objective of this study was to evaluate the relationship between developmental delays and speech perception in pre-lingually deafened cochlear implant recipients.

Methods

This study was a retrospective review of patient charts conducted at a tertiary referral center. Thirty-five pre-lingually deafened children underwent multichannel cochlear implantation and habilitation at the Kyoto University Hospital Department of Otolaryngology-Head and Neck Surgery. A pre-operative cognitive–adaptive developmental quotient was evaluated using the Kyoto scale of psychological development. Post-operative speech performance was evaluated with speech perception tests two years after cochlear implantation. We computed partial correlation coefficients (controlled for age at the time of implantation and the average pre-operative aided hearing level) between the cognitive–adaptive developmental quotient and speech performance.

Results

A developmental delay in the cognitive–adaptive area was weakly correlated with speech perception (partial correlation coefficients for consonant–vowel syllables and phrases were 0.38 and 0.36, respectively).

Conclusion

A pre-operative developmental delay was only weakly associated with poor post-operative speech perception in pre-lingually deafened cochlear implant recipients.     

Auditory and speech performance in cochlear implanted ANSD children

Background: Auditory neuropathy spectrum disorder (ANSD) is a distinct type of SNHL that is characterized by the presence of otoacoustic emissions and/or cochlear microphonics. Cochlear implantation was initially not recommended for ANSD children, later studies showed variable outcomes among those subjects.

Objective: To assess the auditory and speech performance of cochlear implanted children with auditory neuropathy spectrum disorder (ANSD) and to compare these results to those obtained from cochlear implanted children with sensorineural hearing loss (SNHL)

Material and methods: 18 cochlear implanted children with ANSD and 40 cochlear implanted children with SNHL were included in this study. Auditory and speech performance results were compared across both subject groups using the Category of Auditory Performance (CAP) and Speech Intelligibility Rate (SIR) tests, with measurements recorded one year post implantation.

Results: Cochlear implanted children with ANSD showed clinically significant improvements that were comparable to those observed from cochlear implanted subjects without ANSD.

Conclusions: Children with ANSD benefit from early cochlear implantation and can reach similar auditory and speech performance results as that achieved by children without ANSD.     

Electrical stimulation rate effects on speech perception in cochlear implants

The objective of this study was to explore cochlear implant users’ speech perception performance in quiet and in noise for low to moderate stimulation rates. Eight postlingually deaf adult users of the Nucleus CI24 cochlear implant (contour electrode array) using the ESPrit 3G speech processor participated in this study. Monosyllabic word recognition in quiet and sentence perception in noise was evaluated for low to moderate stimulation rates of 275, 350, 500, and 900 pulses-per-second/channel (pps/ch). All four stimulation rate programs were balanced for loudness. A repeated ABCD experimental design was employed. Take home practice was provided with each stimulation rate. Subjects also responded to a comparative questionnaire to examine their rate preference for a variety of listening situations. Results for six of the eight subjects showed no significant effect of rate for monosyllables in quiet. However, results for the sentence test in noise demonstrated improvements with 500 or 900 pps/ch stimulation rates in seven out of the eight subjects. Although there was not a close relationship between each subject's subjective preference and the rate program that provided best speech perception, most subjects indicated a preference for 500 pps/ch rate in noise.     

Assessment of auditory skills in 140 cochlear implant children using the EARS protocol

Auditory performance of cochlear implant (CI) children was assessed with the Listening Progress Profile (LiP) and the Monosyllabic-Trochee-Polysyllabic-Word Test (MTP) following the EARS protocol. Additionally, the 'initial drop' phenomenon, a recently reported decrease of auditory performance occurring immediately after first fitting, was investigated. Patients were 140 prelingually deafened children from various clinics and centers worldwide implanted with a MEDEL COMBI 40/40+. Analysis of LiP data showed a significant increase after 1 month of CI use compared to preoperative scores (p < 0.01). No initial decrease was observed with this test. Analysis of MTP data revealed a significant improvement of word recognition after 6 months (p < 0.01), with a significant temporary decrease after initial fitting (p < 0.01). With both tests, children's auditory skills improved up to 2 years. Amount of improvement was negatively correlated with age at implantation.