Monosyllabic Word Recognition Research Articles

Partial Deafness Treatment with the Nucleus Straight Research Array Cochlear Implant

Introduction: The Nucleus Straight Research Array (SRA) cochlear implant has a new 25-mm electrode carrier designed to minimize insertion trauma, in particular allowing easy insertion via the round window. The aims of this study were to measure preoperative to postoperative benefit in terms of speech recognition in quiet and in noise in three groups of patients (electrical complement, EC; electrical stimulation, ES; electro-acoustic stimulation, EAS) with varying levels of low-frequency hearing, and to evaluate the preservation of residual hearing after implantation with the SRA cochlear implant. Methods: The study design was prospective with sequential enrolment and within-subject comparisons: 23 adult cochlear implant candidates were divided into three groups according to their level of preoperative residual hearing at 500 Hz (EC ≤50 dB; 50 dB < EAS < 80 dB; ES ≧80 dB). Monosyllabic word recognition using the SRA cochlear implant in combination with residual low-frequency hearing was assessed at 4 and 13 months after implantation. Hearing threshold levels were also monitored over time. Results: Subjects across all three groups had significant improvements in speech recognition scores (i.e. >20 percentage points) both for listening in quiet (71% of subjects) and in noise (100% of subjects). The average score at 4 months after operation for words presented in quiet was 61.7%, and in 10 dB SNR noise 46.5%, compared to 34.4 and 10.6% preoperatively (p < 0.001). All subjects retained measurable hearing at 500 Hz in the implanted ear at 4 months after the operation; mean increases were 19, 29 and 1 dB for the EC, EAS and ES groups (n = 21). Across frequencies of 125–1000 Hz, the median increase in thresholds was 15 dB up to 13 months postoperatively (n = 15). Conclusions: Speech recognition performance of subjects with various levels of residual low-frequency hearing was significantly improved with the SRA cochlear implant. A high level and rate of hearing preservation was achieved with the SRA implanted using a round window surgical technique. Subjects with preoperative low-frequency hearing levels between 50 and 80 dB HL (EAS group) tended to lose more hearing than those with either better or worse hearing.

Evaluation of noise reduction technologies in a contemporary cochlear implant system

Evaluation of noise reduction technologies in a contemporary cochlear implant system

Time course of Chinese monosyllabic spoken word recognition: Evidence from ERP analyses

Evidence from event-related potential (ERP) analyses of English spoken words suggests that the time course of English word recognition in monosyllables is cumulative. Different types of phonological competitors (i.e., rhymes and cohorts) modulate the temporal grain of ERP components differentially (Desroches, Newman, & Joanisse, 2009). The time course of Chinese monosyllabic spoken word recognition could be different from that of English due to the differences in syllable structure between the two languages (e.g., lexical tones). The present study investigated the time course of Chinese monosyllabic spoken word recognition using ERPs to record brain responses online while subjects listened to spoken words. During the experiment, participants were asked to compare a target picture with a subsequent picture by judging whether or not these two pictures belonged to the same semantic category. The spoken word was presented between the two pictures, and participants were not required to respond during its presentation. We manipulated phonological competition by presenting spoken words that either matched or mismatched the target picture in one of the following four ways: onset mismatch, rime mismatch, tone mismatch, or syllable mismatch. In contrast to the English findings, our findings showed that the three partial mismatches (onset, rime, and tone mismatches) equally modulated the amplitudes and time courses of the N400 (a negative component that peaks about 400ms after the spoken word), whereas, the syllable mismatched words elicited an earlier and stronger N400 than the three partial mismatched words. The results shed light on the important role of syllable-level awareness in Chinese spoken word recognition and also imply that the recognition of Chinese monosyllabic words might rely more on global similarity of the whole syllable structure or syllable-based holistic processing rather than phonemic segment-based processing. We interpret the differences in spoken word processing between Chinese and English listeners as being due to morphosyllabic structural differences between the two languages.

A comparison of the speech recognition and pitch ranking abilities of children using a unilateral cochlear implant, bimodal stimulation or bilateral hearing aids

ObjectiveThe present study compared the speech recognition and pitch ranking abilities of normally hearing children (n=15) to children using a cochlear implant (CI) alone (n=8), bilateral hearing aids (HAs) (n=6), or bimodal stimulation (BMS) (n=9). It was hypothesised that users of BMS would score higher on tasks of speech and pitch perception than children using a CI alone, but not children using HAs. MethodsParticipants were assessed on tasks of monosyllabic word recognition in quiet, sentence recognition in quiet and noise (10dB signal-to-noise ratio), and a pitch ranking task using pairs of sung vowels one, half, and a quarter of an octave apart. ResultsThere were no significant differences between the mean percentage-correct scores of the four participant groups for either words in quiet or sentences in quiet and noise. However, the proportion of bimodal users who scored >80% correct (80%) was significantly greater than the proportion of high-scoring unilateral CI (25%) or bilateral HA users (17%). Contrary to expectations, there was also no significant difference between the pitch ranking scores of users of BMS and users of a CI alone for all three interval sizes (p<0.05, RM-ANOVA). However participants using only acoustic hearing (i.e. the NH and HA groups) scored significantly higher than participants using electrical stimulation (i.e. the CI and BMS groups) on the pitch ranking task (p<0.05; RM-ANOVA). ConclusionsContrary to findings in postlingually deafened adults, we found no significant bimodal advantage for pitch perception in prelingually deafened children. However, the performance of children using electrical stimulation was significantly poorer than children using only acoustic stimulation. Further research is required to investigate the contribution of the non-implanted ears of users of BMS to pitch perception, and the effect of hearing loss on the development of pitch perception in children.

Percepção da fala em deficientes auditivos pré-linguais usuários de implante coclear

cochlear implant is a rather processing electronic device in terms of its benefits, as it provides the deaf child with the appropriation of incidental oral language. to evaluate the hearing performance of the first 60 children with pre-lingual sensorineural hearing loss who were implanted at the Audiologic Research Centre of the Hospital de Reabilitação de Anomalias Craniofaciais of the University of São Paulo (CPA-HRAC/USP), 16 years after the implementation of the cochlear implant programme. 57 children aged between 9 and 18 years were evaluated using the following speech perception tests: lists of monosyllabic and disyllabic word recognition; lists of meaningless syllables recognition - Consonant Confusion Study - Confuse Program (presented in the System to Deploy Cochlear Nucleus software in its programming unit - version 6.90); lists of sentence recognition and list of words used for the assessment of speech sound perception for children with hearing impairment. all children achieved satisfactory results with the cochlear implant. In the tests involving the index of phoneme and word recognition, the results were statistically significant for the type of cochlear implant Med-El when compared to the other types of implants. the study indicates that the cochlear implant has brought real benefits for the group of studied children, as it allowed the maximum development of the auditory skills.

Evidence for the Expansion of Adult Cochlear Implant Candidacy

The primary objective of this study was to determine whether a revision and/or expansion of current audiologic cochlear implant candidacy criteria is warranted. The study design was a retrospective review of postoperative speech perception performance for 22 adult cochlear implant recipients who demonstrated preoperative Consonant Nucleus Consonant word recognition scores of 30% or higher in the best-aided condition. This criterion was chosen to exceed that specified by the North American clinical trial of the Nucleus Freedom cochlear implant system. The mean preoperative best-aided monosyllabic word score for the 22 patients was 41% correct. The degree of postoperative benefit for the best postoperative condition (electric only or bimodal) ranged from 10 to 68 percentage points with a mean benefit of 27 percentage points for the electric-only condition and 40 percentage points for the bimodal condition. Statistical analyses revealed highly significant differences between preoperative-aided, implant-only, and bimodal performance on Consonant Nucleus Consonant monosyllabic word recognition performance. That is, both postoperative scores--electric only and bimodal--were significantly different from one another and from the preoperative best-aided performance. The current results suggest that a large-scale reassessment of manufacturer and Medicare preoperative audiologic candidacy criteria for adults is warranted to allow more hearing-impaired individuals to take advantage of the benefits offered by cochlear implantation.

Short-term hearing aid benefit in a large group.

Short-term benefit in a very large group (N = 4,584) following hearing aid treatment was estimated using a revised version of the Self-Assessment of Communication (SAC-Hx). A total of 4,584 veterans with adult-onset hearing loss and mean audiometric findings consistent with a mild to severe, sloping, symmetrical, sensorineural hearing impairment were fitted with hearing aids. Responses to the SAC-Hx were gathered prior to and then 6 weeks following hearing aid fitting. Benefit was defined as the difference between the baseline and the posttreatment SAC-Hx scores. Hearing aid treatment resulted in robust and statistically significant benefit in each category of self-perceived communication consequences. Prior experience influenced benefit: New hearing aid users demonstrated the greatest magnitude of benefit, but even previously satisfied and dissatisfied users obtained significant benefit after new hearing aid fitting. Duration of experience did not have a remarkable effect on the magnitude of benefit: All groups with various durations of experience obtained comparable benefit. Severity of the baseline scores paralleled degree of hearing impairment when impairment was defined using a better ear pure tone average at 1,000, 2,000, 3,000, and 4,000 Hz. Also, severity of perceived communication consequences paralleled poorer monosyllabic word recognition. Hearing aid treatment provided a functional, robust, and statistically significant benefit to individuals in all categories of hearing impairment (normal, mild, moderate, severe, and profound). This report demonstrates the feasibility of the SAC-Hx as a tool to efficiently assess outcome domains in hearing aid fitting.

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.

Role of Electrode Placement as a Contributor to Variability in Cochlear Implant Outcomes

Suboptimal cochlear implant (CI) electrode array placement may reduce presentation of coded information to the central nervous system and, consequently, limit speech recognition. Generally, mean speech reception scores for CI recipients are similar across different CI systems, yet large outcome variation is observed among recipients implanted with the same device. These observations suggest significant recipient-dependent factors influence speech reception performance. This study examines electrode array insertion depth and scalar placement as recipient-dependent factors affecting outcome. Scalar location and depth of insertion of intracochlear electrodes were measured in 14 patients implanted with Advanced Bionics electrode arrays and whose word recognition scores varied broadly. Electrode position was measured using computed tomographic images of the cochlea and correlated with stable monosyllabic word recognition scores. Electrode placement, primarily in terms of depth of insertion and scala tympani versus scala vestibuli location, varies widely across subjects. Lower outcome scores are associated with greater insertion depth and greater number of contacts being located in scala vestibuli. Three patterns of scalar placement are observed suggesting variability in insertion dynamics arising from surgical technique. A significant portion of variability in word recognition scores across a broad range of performance levels of CI subjects is explained by variability in scalar location and insertion depth of the electrode array. We suggest that this variability in electrode placement can be reduced and average speech reception improved by better selection of cochleostomy sites, revised insertion approaches, and control of insertion depth during surgical placement of the array.

A Novel Implantable Hearing System with Direct Acoustic Cochlear Stimulation

A new implantable hearing system, the direct acoustic cochlear stimulator (DACS) is presented. This system is based on the principle of a power-driven stapes prosthesis and intended for the treatment of severe mixed hearing loss due to advanced otosclerosis. It consists of an implantable electromagnetic transducer, which transfers acoustic energy directly to the inner ear, and an audio processor worn externally behind the implanted ear. The device is implanted using a specially developed retromeatal microsurgical approach. After removal of the stapes, a conventional stapes prosthesis is attached to the transducer and placed in the oval window to allow direct acoustical coupling to the perilymph of the inner ear. In order to restore the natural sound transmission of the ossicular chain, a second stapes prosthesis is placed in parallel to the first one into the oval window and attached to the patient’s own incus, as in a conventional stapedectomy. Four patients were implanted with an investigational DACS device. The hearing threshold of the implanted ears before implantation ranged from 78 to 101 dB (air conduction, pure tone average, 0.5–4 kHz) with air-bone gaps of 33–44 dB in the same frequency range. Postoperatively, substantial improvements in sound field thresholds, speech intelligibility as well as in the subjective assessment of everyday situations were found in all patients. Two years after the implantations, monosyllabic word recognition scores in quiet at 75 dB improved by 45–100 percent points when using the DACS. Furthermore, hearing thresholds were already improved by the second stapes prosthesis alone by 14–28 dB (pure tone average 0.5–4 kHz, DACS switched off). No device-related serious medical complications occurred and all patients have continued to use their device on a daily basis for over 2 years.

Speech Recognition Materials and Ceiling Effects: Considerations for Cochlear Implant Programs

Cochlear implant recipients have demonstrated remarkable increases in speech perception since US FDA approval was granted in 1984. Improved performance is due to a number of factors including improved cochlear implant technology, evolving speech coding strategies, and individuals with increasingly more residual hearing receiving implants. Despite this evolution, the same recommendations for pre- and postimplant speech recognition testing have been in place for over 10 years in the United States. To determine whether new recommendations are warranted, speech perception performance was assessed for 156 adult, postlingually deafened implant recipients as well as 50 hearing aid users on monosyllabic word recognition (CNC) and sentence recognition in quiet (HINT and AzBio sentences) and in noise (BKB-SIN). Results demonstrated that for HINT sentences in quiet, 28% of the subjects tested achieved maximum performance of 100% correct and that scores did not agree well with monosyllables (CNC) or sentence recognition in noise (BKB-SIN). For a more difficult sentence recognition material (AzBio), only 0.7% of the subjects achieved 100% performance and scores were in much better agreement with monosyllables and sentence recognition in noise. These results suggest that more difficult materials are needed to assess speech perception performance of postimplant patients – and perhaps also for determining implant candidacy.

Hearing Preservation in Patients With a Cochlear Implant

Hearing Preservation in Patients With a Cochlear Implant

Contribution of High Frequencies to Speech Recognition in Quiet and Noise in Listeners With Varying Degrees of High-Frequency Sensorineural Hearing Loss

The contribution of audible high-frequency information to speech-understanding performance in listeners with varying degrees of high-frequency sensorineural hearing loss was examined. Thirty-six elderly hearing-impaired (EHI) and 24 young normal-hearing (YNH) listeners were tested in quiet (+20 dB speech-to-noise ratio [SNR]) and noise (+5 dB SNR) and under different bandpass conditions (narrow, 200-1600 Hz; midband, 200-3200 Hz; broadband, 200-6400 Hz), both without and with spectral shaping of the stimuli. Monosyllabic word-recognition performance was examined through use of both whole-word scoring and phoneme scoring. The 36 EHI listeners were divided into 3 groups of 12 listeners each, with the groups differing in the amount of high-frequency hearing loss. The 24 YNH participants were separated into 2 groups, each serving as a reference group for either the unshaped or spectrally shaped speech listening conditions. Results for spectrally shaped speech, in both quiet and noise, revealed that the 3 EHI groups performed equivalently in the different bandwidth conditions and demonstrated no change (increase or decrease) in word-recognition performance between the midband and broadband conditions. The YNH groups, however, demonstrated improved speech understanding attributable to the higher frequencies for the broadband condition in both the unshaped and shaped conditions. Data from the EHI listeners revealed that performance for unshaped speech was correlated moderately and negatively with degree of high-frequency hearing loss. Alternatively, recognition performance for shaped speech was related to neither the performance for unshaped speech nor the amount of high-frequency hearing loss.

Effects of Word Difficulty and Talkers on Monosyllabic Word Recognition Tests

청각의 역할 중 중요시되는 것은 어음이 포함된 소리를 뇌로 전달하여 의사소통을 가능하게 하는 것이다. 청각 기능이 저하될 경우에 순음을 이용한 청력평가도 실시하는데, 가장완벽한 자극은 어음이라고 보고되고 있다.15) 어음평가 중에 흔히 사용되는 것으로 어음명료도를 제시 할 수 있는데, 한 보고에 의하면 미국 청각사들 가운데 응답자의 56%가 한 쪽귀에 25개의 일음절만 제시하여 결과를 얻는다고 하였다.9)이러한 평가 방식은 객관적인 논리와 원리를 중요시하는 일부 청각 연구자들에 의해 비평을 받지만, 평가 소요 시간과 피검자의 피로를 줄일 수 있기 때문에 미국의 많은 임상 현 장에서 빈번히 사용되고 있다. 국내에서도 25개로 이루어진 half list나 어려운 10개의 일음절 목록이 표준화되어 널리 상용된다면 평가 진행뿐만 아니라 결과의 표준화에도 도움이 될 것이다. 이러한 축소된 어음목록의 개발에 있어서 중요한 기준 중에 한 가지가 리스트 간 어음의 난이도이다. 어떤 어 음 목록은 너무 쉬워서 청력 손실 정도를 구별하지 못하고 정확한 명료도평가 결과를 얻는데 효과적이지 못하다.9) 따라서 본 연구에서는 어음검사에 영향을 미치는 자극 난이도 및 화자변수와 관련된 자료 들을 살펴보고, 한국어 일음절 250개에 대한 인지도 평가를 실시하여 각 어음의 난이도를 분석한 후에 남·녀 성별에 의한 차이가 있는지 알아보고자 하였다.

Effects of bilingualism, noise, and reverberation on speech perception by listeners with normal hearing

This study compared monosyllabic word recognition in quiet, noise, and noise with reverberation for 15 monolingual American English speakers and 12 Spanish–English bilinguals who had learned English prior to 6 years of age and spoke English without a noticeable foreign accent. Significantly poorer word recognition scores were obtained for the bilingual listeners than for the monolingual listeners under conditions of noise and noise with reverberation, but not in quiet. Although bilinguals with little or no foreign accent in their second language are often assumed by their peers, or their clinicians in the case of hearing loss, to be identical in perceptual abilities to monolinguals, the present data suggest that they may have greater difficulty in recognizing words in noisy or reverberant listening environments.

Speech perception in elderly patients following cochlear implantation

Conclusions. Elderly patients benefit from cochlear implantation in terms of speech perception and quality of life. Age alone should be no contraindication for implantation. Objective. There have been concerns whether elderly patients may perform poorly after cochlear implantation due to degenerative processes in the central and peripheral auditory systems. The purpose of this study was to analyze the benefits of cochlear implantation in elderly patients in comparison to younger recipients. Material and methods. We examined 26 postlingually deafened adults aged > 65 years who received a cochlear implant at our center regarding preoperative findings, comorbidities, postoperative complications and quality of life. Speech perception was assessed by means of multi- and monosyllabic word recognition and compared to the results obtained by younger patients. Results. The surgical procedure was well tolerated by all patients without notable perioperative complications. In terms of speech perception, no significant differences between the elderly patients and younger recipients were noted. All patients found that cochlear implantation had a positive impact on their quality of life.

Choice of ear for cochlear implantation: the effect of history and residual hearing on predicted postoperative performance.

This study used mathematical formulas predicting cochlear implant outcomes to investigate the effects of implantation in the poorer ear on postoperative speech recognition. Retrospective cohort study with mathematical and statistical analyses. This study used the University of Iowa formula for predicting outcomes derived from implantation of the better ear on the basis of duration of deafness and preoperative speech understanding, applying this predictive model to a cohort of patients undergoing implantation in the poorer ear at The Johns Hopkins Medical Center. Tertiary referral center with active cochlear implant program. Postlingually deafened adults (n = 58) with preoperative Central Institute for the Deaf sentence scores less than or equal to 40%. Cochlear implantation with all three Food and Drug Administration-approved devices. Postoperative monosyllabic word recognition scores and correlations between actual and predicted results. There was good statistical correlation between the predicted postoperative performance using the University of Iowa formula and the actual performance of our cohort of patients undergoing implantation in the poorer ear (r = 0.50, p < 0.0001). In addition, as a population, our cohort had a mean postoperative consonant-nucleus-consonant word score of 41.8%, which was statistically the same as that predicted by the University of Iowa formula (43.6%). The postoperative performance of cochlear implant patients is most closely correlated with duration of deafness. However, our results indicate that this measure may not be ear specific and is more reflective of the total auditory receptivity of the patient. These observations help to form guidelines for choice of ear for implantation.

Conversion from the Body-worn Spectra to the Ear-level ESPrit22 in Children

A multi-centre study was conducted involving 93 children, aged 5.7 to 18.0 years, who approached their cochlear implant centres for conversion from the body-worn Spectra to the ear-level ESPrit22 processor. Eighty-seven per cent of the children attending the centres could be fitted with the ESPrit22 without any program adjustment, 9% required some adjustment and 4% were unable to be fitted with the ESPrit22 because of high power requirements in the speech processor program. For subjects requiring significant adjustment to stimulation mode for ESPrit22 fitting an initial decrease in word recognition was observed, with progressive improvement over time. For those subjects where direct conversion from the Spectra to the ESPrit22 was possible (n = 60) mean monosyllabic open-set word recognition at initial fitting was equivalent between the two processors. However after using the ESPrit22 for a period of 4 weeks there was a significant improvement in performance from 46.5% with the Spectra to 54.4% with the ESPrit22. A similar pattern was observed for BKB sentence recognition in noise with a smaller group of 8 subjects. The majority of children reported immediate adjustment to the ESPrit22 and chose to use the ESPrit22 for most of the time in a range of listening environments.

Cochlear implant performance in senior citizens

Cochlear implants are indicated for elderly patients with severe-to-profound hearing loss (sensorineural hearing loss ≥70 dB). Their use has been limited, possibly by the misconception that elderly patients will perform poorly. To document the performance of older adults (≥65 years old), we undertook a retrospective analysis of our postlingually deafened adult patients who underwent implantation with the CLARION Multi-Strategy Cochlear Implant and underwent formal audiologic analysis (sentence recognition [Central Institute for the Deaf, CID] and monosyllabic word recognition (consonant-noun-consonant, CNC)). Both younger (n = 20; mean age = 46.9 years) and older (n = 16; mean age = 71.5 years) adults showed statistically significant increases in CID and CNC scores after cochlear implantation. No statistically significant difference could be detected in operative time, anesthesia time, length of hospitalization, or CID or CNC scores between the two age groups. We conclude that age should not be a criterion for deciding who should receive cochlear implants. (Otolaryngol Head Neck Surg 2000;123:419-24.)

Erratum: “Monosyllabic word recognition at higher-than-normal speech and noise levels” [J. Acoust. Soc. Am. 105, 2431–2444 (1999)

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