Speech Perception Scores Research Articles

Auditory cortical N100 in pre- and post-synaptic auditory neuropathy to frequency or intensity changes of continuous tones

ObjectivesAuditory cortical N100s were examined in ten auditory neuropathy (AN) subjects as objective measures of impaired hearing. MethodsLatencies and amplitudes of N100 in AN to increases of frequency (4–50%) or intensity (4–8dB) of low (250Hz) or high (4000Hz) frequency tones were compared with results from normal-hearing controls. The sites of auditory nerve dysfunction were pre-synaptic (n=3) due to otoferlin mutations causing temperature sensitive deafness, post-synaptic (n=4) affecting other cranial and/or peripheral neuropathies, and undefined (n=3). ResultsAN consistently had N100s only to the largest changes of frequency or intensity whereas controls consistently had N100s to all but the smallest frequency and intensity changes. N100 latency in AN was significantly delayed compared to controls, more so for 250 than for 4000Hz and more so for changes of intensity compared to frequency. N100 amplitudes to frequency change were significantly reduced in ANs compared to controls, except for pre-synaptic AN in whom amplitudes were greater than controls. N100 latency to frequency change of 250 but not of 4000Hz was significantly related to speech perception scores. ConclusionsAs a group, AN subjects’ N100 potentials were abnormally delayed and smaller, particularly for low frequency. The extent of these abnormalities differed between pre- and post-synaptic forms of the disorder. SignificanceAbnormalities of auditory cortical N100 in AN reflect disorders of both temporal processing (low frequency) and neural adaptation (high frequency). Auditory N100 latency to the low frequency provides an objective measure of the degree of impaired speech perception in AN.

Preliminary Results of Electric and Acoustic Stimulation Using the MED-EL Sonata Flex EAS Electrode Array

Electric Acoustic Stimulation is the combination of acoustic stimulation (via a hearing aid) and electric stimulation (via a cochlear implant) in the implanted ear. This paper summarises the preliminary speech perception scores and hearing preservation in adult patients (n = 9) implanted with the Sonata FlexEAS electrode array. Subjects were adult candidates who met the national guidelines for cochlear implantation yet had some usable low frequency hearing. The surgical procedure aimed to preserve this residual hearing in the ear to be implanted. Patients retaining this usable hearing post operatively were issued with the DUET speech processor which provides a combination of acoustic and electric stimulation. Patients whose residual hearing was not preserved used the OPUS 2 processor in conjunction with the FlexEAS electrode array. The aim of the study was to investigate the speech perception scores of these two patient groups in comparison to patients using the standard Sonata Flex Soft electrode array. We aim to analyse whether patients whose residual hearing was not preserved perform as well as those for whom hearing preservation was not attempted. Results show that hearing preservation is possible in this patient group and the outcomes in terms of aided speech discrimination are potentially excellent. Therefore, it may be prudent to review the criteria for implant candidature in this patient group in the future.

How Internet Telephony Could Improve Communication for Hearing-Impaired Individuals

To test, whether modern Internet telephony with a broadband transmission (0.1-8 kHz) of speech improves speech perception in comparison to conventional telephony (0.3-3.5 kHz) in hearing-impaired and normal-hearing adults. Experimental clinical study. Audiologic laboratory in a tertiary referral center in Bern, Switzerland. Twenty-one adult hearing-impaired patients consisting of 11 users of cochlear implants and 10 users of hearing aids were selected from the institution's database based on pure tone audiograms, speech perception scores, and device settings. Ten normal-hearing adults served as controls. Superiority trial of speech perception assessed with Internet versus conventional telephone quality and noninferiority trial of Internet telephone versus frequency restricted, uncompressed audio CD quality. A modern broadband codec was chosen to simulate Internet telephone quality, and ideal network conditions without packet loss were assumed. Speech perception scores of a monosyllabic word test in quiet and a sentence test in background noise assessed in different audio qualities. : Test scores were, on average, 15% (4-33) higher in the monosyllabic word and 25% (8-51) higher in the sentence test using Internet versus conventional telephone quality across all subject groups. Speech perception was not significantly different when Internet telephone quality was compared with high-cut CD quality. Internet telephony offers significantly improved speech perception to hearing-impaired and normal-hearing adults under ideal laboratory conditions through doubling the frequency range and through conserving audio quality during digital sound processing.

Electric acoustic stimulation of the auditory system: experience and results of ten patients using MED‐EL’s M and FlexEAS electrodes

To evaluate the hearing preservation rate and speech perception scores in patients with profound high frequency hearing loss and acoustically aidable low frequency hearing, managed with the MED-EL electric acoustic stimulation system referenced to the insertion depth of the electrode array. Retrospective data analysis. Ten patients implanted at the Auditory Implant Centre, Guy's and St Thomas's Hospital, London, UK. Pure tone audiometry, speech perception tests and electrode insertion depth angle. Postoperatively, functional hearing preservation allowing electric acoustic stimulation was achieved in eight patients and total preservation of residual hearing in five patients with follow-up periods of more than 12 months. Three of four (75%) patients with an insertion depth of >360 degrees had a threshold shift of >25 dB, and all four patients had a threshold shift of >10 dB. All patients with total hearing preservation had the electrode inserted up to 360 degrees at maximum. Overall, speech perception outcomes increased significantly and hearing impairment was significantly reduced after electric acoustic stimulation or electric stimulation alone as compared with the preoperative scores. Electric acoustic stimulation provides significant benefit to individuals with profound high frequency hearing loss. Studies with larger number of patients are needed to establish the optimal electrode insertion angle as well as to further analyse the benefit of electric acoustic stimulation.

A primer on classroom acoustics.

Research involving quantitative and qualitative evaluation of classroom activities has shown that speech perception and intelligibility in elementary, middle, and high schools can be measured, modeled, and simulated based on an impulse response‐based theory. The theory combines the vocal production of the speaker, the hearing abilities of the listeners, the strength of the direct sound and early sound reflections from room surfaces, duration of longer term reverberation, and the level, type, information content, and frequency content of intruding sounds. Regression models relating measured intelligibility in classrooms to measured, modeled, and simulated sounds show model r2 > 0.90. A model relating speech perception score to the level, type, information content, and frequency content of typical classroom noise reaches r2 > 0.90 as well. The impulse response based measures are reduced to a series of architectural systems that can be implemented using alternate construction systems to meet budget requirements.

Cochlear Implantation in Neurofibromatosis Type 2 After Radiation Therapy

To investigate the results of cochlear implantation in patients with neurofibromatosis Type 2 (NF2) who have previously been treated with radiation therapy to the vestibular schwannoma (VS) in their only hearing ear. A retrospective review of the Melbourne Cochlear implant database was undertaken to identify patients with NF2 undergoing cochlear implantation in whom previous radiation therapy had been performed to control their VS (ipsilateral tumor). Three patients were identified. A case note review was undertaken and data collected on preoperative and postoperative speech perception testing. Melbourne Cochlear implant center. All 3 patients were daily cochlear implant users. There was improvement in speech perception scores in 2 cases, with the 3rd case unable, for unrelated medical reasons, to complete postoperative testing. Subjectively, the third patient reported a dramatic improvement in communication and is a daily user of his implant. Cochlear implantation results in improved hearing in a select group of NF2 patients who have undergone radiation treatment to control their VS.

Longitudinal Study of Speech Perception, Speech, and Language for Children with Hearing Loss in an Auditory-Verbal Therapy Program

This study examined the speech perception, speech, and language developmental progress of 25 children with hearing loss (mean Pure-Tone Average [PTA] 79.37 dB HL) in an auditory-verbal therapy program. Children were tested initially and then 21 months later on a battery of assessments. The speech and language results over time were compared with those for a control group of children with typical hearing who were matched for initial language age, receptive vocabulary, gender, and socioeconomic level. Speech perception scores for the children with hearing loss showed significant improvement (p 0.05). At the 21-month test point, 84% of the children with hearing loss scored within the typical range for total language age, compared to 58.6% at the initial assessment. Receptive vocabulary scores were an exception, with the children with typical hearing showing significantly more gain than the children with hearing loss (p < 0.05). Nevertheless, the group with hearing loss scored within the typical range for receptive vocabulary. Overall, the results show that the children with hearing loss had improved speech perception skills over time and that their rate of progress for speech and language skills was similar to that of children with typical hearing.

Cochlear implantation in children with cognitive impairments

Cochlear implantation in children with cognitive impairments

Auditory performance after cochlear implantation in late septuagenarians and octogenarians.

Previous studies have demonstrated consistent benefit in older adults undergoing cochlear implantation as compared with younger control groups, with age category thresholds between 60 and 70 years. The objective of this study is to report auditory performance in implant recipients older than 75 years, a cohort for which few data have been reported. Retrospective chart review. Academic cochlear implant program in a tertiary-care hospital. : Twenty-eight cochlear implant recipients were subdivided into implant users older than 80 years (Group 1) and recipients currently older than 75 years (Group 2). Cochlear implantation. Open-set speech perception scores. : Postoperative open-set speech perception scores were compared with preoperative scores in the best-aided condition. Criteria were developed to define situations where the implant was considered to be nonbeneficial or less beneficial than amplification, and those data were then subjected to Kaplan-Meier analysis. Group 1 included 13 patients with mean age of 80.7 years at the time of implantation. Group 2 included 15 patients with a mean age of 71.6 years. Scores were significantly better postoperatively at 6 months (p < 0.01) for Group 2 and at 12 months (p < 0.01) for both Groups 1 and 2. Kaplan-Meier curves were constructed for both groups. Cochlear implantation in patients older than 75 years is beneficial, and Kaplan-Meier analysis demonstrates that the clinical benefit is durable over time. Patients older than 80 years obtain similar benefit, although auditory performance was less robust.

Speech Perception after Cochlear Implantation in 53 Patients with Otosclerosis: Multicentre Results

Objectives: To analyse the speech perception performance of 53 cochlear implant recipients with otosclerosis and to evaluate which factors influenced patient performance in this group. The factors included disease-related data such as demographics, pre-operative audiological characteristics, the results of CT scanning and device-related factors. Methods: Data were reviewed on 53 patients with otosclerosis from 4 cochlear implant centres in the United Kingdom and the Netherlands. Comparison of demographics, pre-operative CT scans and audiological data revealed that the patients from the 4 different centres could be considered as one group. Speech perception scores had been obtained with the English AB monosyllable tests and Dutch NVA monosyllable tests. Based on the speech perception scores, the patients were classified as poor or good performers. The characteristics of these subgroups were compared. Results: There was wide variability in the speech perception results. Similar patterns were seen in the phoneme scores and BKB sentence scores between the poor and good performers. The two groups did not differ in age at onset of hearing loss, duration of hearing loss, progression, age at onset of deafness, or duration of deafness. Conclusions: The clinical presentation of the otosclerosis (rapid or slow progression) did not influence speech perception. Better performance was related to less severe signs of otosclerosis on CT scan, full insertion of the electrode array, little or no facial nerve stimulation and little or no need to switch off electrodes.

Categorical speech perception deficits distinguish language and reading impairments in children

We examined categorical speech perception in school-age children with developmental dyslexia or Specific Language Impairment (SLI), compared to age-matched and younger controls. Stimuli consisted of synthetic speech tokens in which place of articulation varied from 'b' to 'd'. Children were tested on categorization, categorization in noise, and discrimination. Phonological awareness skills were also assessed to examine whether these correlated with speech perception measures. We observed similarly good baseline categorization rates across all groups; however, when noise was added, the SLI group showed impaired categorization relative to controls, whereas dyslexic children showed an intact profile. The SLI group showed poorer than expected between-category discrimination rates, whereas this pattern was only marginal in the dyslexic group. Impaired phonological awareness profiles were observed in both the SLI and dyslexic groups; however, correlations between phonological awareness and speech perception scores were not significant. The results of the study suggest that in children with language and reading impairments, there is a significant relationship between receptive language and speech perception, there is at best a weak relationship between reading and speech perception, and indeed the relationship between phonological and speech perception deficits is highly complex.

Cochlear Reimplantation after Surgery for Electric-Acoustic Stimulation

Background/Aims: Combined electric-acoustic stimulation (EAS) of the auditory system usually results in better speech understanding than electric stimulation only, assuming low-frequency hearing can be preserved. Treatment options and outcomes for 4 subjects experiencing compromised hearing after EAS surgery are discussed. Methods: Each subject underwent revision surgery to replace the original 21-mm electrode arrays used in EAS surgery with cochlear implants (CIs) with 31-mm arrays. Our aims were: (1) to investigate whether deeper insertion is possible, and (2) to evaluate the influence of electrode insertion angle by comparing speech perception scores before and after revision surgery. Results: Deeper insertion was feasible in all subjects. Speech understanding scores after reimplantation were comparable to those seen after the first intervention. Conclusion: A 360-degree insertion under EAS conditions provides sufficient speech understanding, even in cases of additional hearing loss. Reimplantation with a longer electrode array is feasible in former EAS patients.

Psychometric validity of the Cochlear Implant Function Index (CIFI): a quality of life assessment tool for adult cochlear implant users

Objective The Cochlear Implant Function Index (CIFI) is created to assess adult cochlear implant (CI) auditory effectiveness in real world situations. Our objective is to evaluate the CIFI as a reliable psychometric tool to assess 1) reliance on visual assistance, 2) telephone use, 3) communication at work, 4) ‘hearing’ in noise, 5) in groups, and 6) in large room settings. Study Design Based upon Guttman scaling properties, the CIFI elicits implanted respondent's functional level with auditory independence from Level 1 (still requiring signing) to level 4 (without any help beyond CI). A blinded, retrospective questionnaire is anonymously answered by cochlear implant recipients. Setting CI centers of tertiary care medical centers, CI support group, and an interactive web page of a hearing and speech center in a large metropolitan region. Subjects 245 respondents from a varied adult CI population implanted for one month to 19 years prior to answering the questionnaire. Intervention An assessment tool of CI function. Main Outcome Measure A coefficient of reproducibility (CR) for the Guttman scale format equal or greater than 0.90, indicating good scalability. Results CR in the CIFI was above 0.90. Effective scalability and mean scores from 2.5 to 3.5 for the six areas examined (1.00−4.00) were achieved. Conclusion The psychometric properties of this user friendly survey demonstrate consistently good scalability. Based on these findings, the CIFI provides a validated tool that can be used for systematic comparisons between groups of patients or for follow-up outcomes in patients who use cochlear implants. Further study is indicated to correlate CIFI scores with sound and speech perception scores. Copyright © 2009 John Wiley & Sons, Ltd.

Speech coding with traveling wave delays: Desynchronizing cochlear implant frequency bands with cochlea-like group delays

Traveling wave delays are the frequency-dependent delays for sounds along the cochlear partition. In this study, a set of suitable delays was calibrated to cochlear implant users’ pitch perception along the implanted electrode array. These delays were then explicitly coded in a cochlear implant speech processing strategy as frequency specific group delays. The envelopes of low frequency filter bands were delayed relative to high frequencies, with amplitude and fine structure unmodified. Incorporating such delays into subjects’ own processing strategies in this way produced a significant improvement in speech perception scores in noise. A subsequent investigation indicated that perceptual sensitivity to changes in delay size was low and so accurate delay calibration may not be necessary. It is proposed that contention between broadband envelope cues is reduced when frequency bands are de-synchronized.

Understanding vocoded speech in steady and amplitude modulated bandpass noise.

Vocoded speech perception was investigated in amplitude-modulated bandpass noise to assess normal-hearing listeners’ speech understanding through cochlear implant simulations with temporal and spectral interference. Sixteen vocoder bands were applied to IEEE sentences and white noise [Fu and Nogaki (2004)]. The lower 10 bands were maintained for speech, eliminating the upper bands. The spectra of vocoded noises were set to be completely overlapping, partially overlapping, and completely separate from the speech bands. Amplitude modulations (AMs) were imposed on the noises, varying from 25–300 Hz. AM detection thresholds were measured for 80-ms white noise carriers, with rates of 25, 100, and 300 Hz. Preliminary data showed that: (1) vocoded speech perception scores were significantly different between listeners, ranging from 53–80% in quiet and from 10–54% in overlapping noise; (2) the spectra of the noise bands affected vocoder speech perception, with greater overlap causing reduced scores; (3) the noise AM rate did not significantly affect speech scores; however, vocoded speech perception in noise was significantly correlated with AM detection thresholds at 25 Hz. Results suggest that the spectral overlap of noise and speech causes reduced performance even when the noise is modulated. [Research supported by the Univ. of Minnesota.]

The use of intra-operative electrical auditory brainstem responses to predict the speech perception outcome after cochlear implantation

Electrically evoked auditory brainstem responses (EABR) were obtained intra-operatively from children receiving full insertion of Cochlear CI24 implant. The EABR waveform was quantified according to the presence or absence of waves (eII-eV). Each trace was scored from 0–3 providing a maximum score for all 22 electrodes of 66 in the monopolar mode. Speech perception scores were measured after one year in 245 children and after two years of cochlear implant use in 148 children. Significant differences in the EABR waveforms were found between those recipients who achieved scores of 4 or greater on the Melbourne scale and those recipients who only had a modest outcome. After two years, the outcome showed even greater differences. The group of 103 children who had outcomes of 4 or greater at one year improved from a mean score of 4.7 to 5.7. The group of 45 children who had outcomes of 3 or less at one year only improved from a mean score of 2.9 to 3.15. In this latter group, only four children showed any significant improvement. Copyright © 2009 John Wiley & Sons, Ltd.

The Effects of Cochlear Implant Electrode Deactivation on Speech Perception and in Predicting Device Failure

To examine speech perception outcomes as related to a reduction in the number of functional electrodes postimplantation and to determine the effect of electrode reduction on subsequent device failure. Retrospective review. Tertiary academic referral center. Of 1,520 children and adults with full insertions of the Advanced Bionics, Med El, and Nucleus devices, 15 (1%) were patients. Patients were included in the study if all electrodes were functional at initial stimulation, but the number of electrodes in use was subsequently reduced at follow-up programming sessions. Exclusion criteria included partial and split-array electrode insertions. Patients with bilateral severe to profound sensorineural hearing loss underwent either unilateral or bilateral cochlear implantation. Postimplantation speech perception tests obtained with a full complement of functional electrodes were performed and the results compared to those obtained with 1 or more electrodes removed from the user program. Electrode deactivation was also correlated with device failure. The results of this study indicate that deactivation of cochlear implant electrodes is relatively uncommon, and although the deactivation does not have a direct influence on speech performance outcomes, the loss of 5 or more electrodes can suggest impending device failure. Additionally, those patients with electrode deactivation coupled with a decline in speech perception scores should also be considered at risk for device failure.

Effect of Bimodal Hearing in Speech Perception Under Noisy Environment According to Residual Hearing

Background and Objectives：In this study, we evaluated the effect of bimodal hearing in the speech perception test and the increasing level of bimodal hearing over cochlear implantation in speech perception score regarding residual hearing. Subjects and Method：Nineteen prelingually deaf patients, who had used bimodal hearing over a period of 8 months, were divided in two groups in accordance to their low frequency residual hearing. The children were tested in open-set speech perception under +10 SNR and +20 SNR. The scores of bimodal hearing and unilateral cochlear implantation were compared by the Wilcoxon signed-rank test. Also, the increased level of speech perception scores of bimodal hearing over cochlear implantation alone were calculated using the formula, [bimodal score (%) - unilateral cochlear implantation (%)], and was compared between groups. Results：In pure tone audiometry under silent condition, the result of bimodal hearing was similar to unilateral cochlear implantation in magnitude in both groups. Under the noisy condition, both groups had better result in bimodal hearing in terms of speech perception. Also, the increased level was higher in bimodal hearing over unilateral cochlear implantation in the better residual hearing group. However, since the sample size was small enough, it is considered that there was no statistical significance. Conclusion：Cochlear implanted patients with residual hearing are expected to get better speech perception in noisy environment with bimodal hearing regardless of the level of residual hearing. (Korean J Otorhinolaryngol-Head Neck Surg 2009;52:29-35)

電極のトラブルに対して人工内耳入れ替え手術を行った２例

We report two cases of cochlear reimplantation due to electrode problems. Case 1: A 76-year-old woman, complaining right-ear tinnitus in the 8 years following CI22 cochlear implantation in the right ear, was found in an X-ray examination to have the electrode array bending near the cochlear stoma. In cochlear reimplantation using a CI22 device upgraded to CI24RCS, fibrous tissue around the stoma and in the cochlear basal turn was removed and the electrode was replaced. Her speech perception score improved thereafter and tinnitus was reduced. Case 2: A 6-year-old boy with bilateral inner ear malformation presented with right facial spasm and decreased speech recognition 2 years and 4 months after right-ear cochlear implantation. An X-ray examination showed slight electrode slipout, so we inserted a CI24M device upgraded to CI24RCS, after which his speech perception score improved. Cochlear reimplantation was thus proved to be safe and effective in cases of electrode problems.

Open-Set Monosyllabic Speech Perception Test for Preschool Children

Background and Objectives：An open-set monosyllabic speech perception test is necessary, not only to devise habilitation programs but to select candidates and estimate performance in pediatric cochlear implant program. The purpose of this study is to develop a validated open-set monosyllabic speech perception test for preschool children. Subjects and Method：Qualitative test development was based on vocabulary familiarity, syllabic and phonemic frequency, and phonetic balancing between the lists. The devised test lists were applied to 138 normal hearing children and 46 children with cochlear implant to examine the validity and reliability. Results：The final two test lists were made up of 100 items with 260 phonemics. The consequential validity of this devised test was proven by the applied results that the speech perception score of children with implanted devices was significantly lower than that of normal children, when controlling for the length of auditory experience. Conclusion：The developed monosyllabic speech perception test is the validated instrument for preschool children. It is sensitive to perceptual characteristics of articulatory function in cochlear implanted children. The validity of this test needs to be enhanced by clinical application and further item analysis. (Korean J Otorhinolaryngol-Head Neck Surg 2009;52:312-21)