Chronic neuroangiostrongyliasis: case study of chronic presentations in Hawaii.

This paper describes chronic features of neuroangiostrongyliasis (NAS), a long-term outcome of the disease that has not been adequately described. Current and past literature is predominantly limited to acute manifestations of NAS, and mention of chronic, ongoing clinical symptoms is usually limited to brief notes in a discussion of severe cases. This study investigated the long-term outcomes in ten individuals who were diagnosed with acute neuroangiostrongyliasis in Hawaii between 2009 and 2017. The study demonstrates a significant number of persons in Hawaii sustain residual symptoms for many years, including troublesome sensory paresthesia (abnormal spontaneous sensations of skin experienced as 'burning, pricking, pins and needles'; also described as allodynia or hyperesthesia) and extremity muscle pains. As a consequence, employment and economic hardships, domestic relocations, and psychological impairments affecting personal relationships occurred. The study summarizes common features of chronic disease, sensory paresthesia and hyperesthesia, diffuse muscular pain, insomnia, and accompanying emotional distress; highlights the frequently unsuccessful endeavours of individuals struggling to find effective treatment; proposes pathogenic mechanisms responsible for prolonged illness including possible reasons for differences in disease presentation in Hawaii compared to Southeast Asia.

Corrosive substances ingestion: a review.

Corrosive chemical substance ingestions are a major problem, especially in developing countries, but also in developed countries such as the United States, France, and Belgium. Ingestions may be deliberate as suicide attempts (mostly in adolescents and adults) or accidental (mostly in children). The results can be devastating in terms of individual suffering and disability, but also in terms of resource utilization and costs. In developing countries, outcomes may be worse because of limited medical/surgical resources. Common sequelae include gastrointestinal (GI) tract (esophagus, stomach, pylorus, and duodenum) stricture formation, GI tract perforation, and hemorrhage. Systemic effects may also occur, such as disseminated intravascular coagulation (DIC), multi-organ system failure, and sepsis. Various interventions in the acute phase to reduce the severity of injury have been attempted, but there are no large controlled clinical trials to demonstrate efficacy. Dilation therapy in various forms is commonly used for the treatment of strictures and a variety of surgical procedures including esophagectomy and delayed replacement may be required in severe corrosive injury cases.

Predictive factors of cochlear implant outcomes in the elderly.

OBJECTIVE: To analyze predictive factors of cochlear implant outcomes and postoperative complications in the elderly. STUDY DESIGN: Prospective, longitudinal study performed in 10 tertiary referral centers. METHODS: Ninety-four patients aged 65-85 years with a profound, postlingual hearing loss were evaluated before implantation, at time of activation, and 6 and 12 months after cochlear implantation. Speech perception and lipreading were measured using disyllabic word recognition in quiet and noise, and lipreading using disyllabic words and sentences. The influence of preoperative factors on speech perception in quiet and noise at 12 months was tested in a multivariate analysis. Complications, presence of tinnitus and of vestibular symptoms were collected at each evaluation. RESULTS: The effect of age was observed only in difficult noisy conditions at SNR 0 dB. Lipreading ability for words and sentences was negatively correlated with speech perception in quiet and noise. Better speech perception scores were observed in patients with shorter duration of hearing deprivation, persistence of residual hearing for the low frequencies, the use of a hearing aid before implantation, the absence of cardiovascular risk factors, and in those with implantation in the right ear. General and surgical complications were very rare, and the percentage of vestibular symptoms remained stable over time. CONCLUSION: This study demonstrates that cochlear implantation in the elderly is a well-tolerated procedure and an effective method to improve communication ability. Advanced age has a low effect on cochlear implant outcome. Analyses of predictive factors in this population provide a convincing argument to recommend treatment with cochlear implantation as early as possible in elderly patients with confirmed diagnosis of a severe-to-profound hearing loss and with only limited benefit from hearing aid use in one ear.

Role of slow temporal modulations in speech identification for cochlear implant users.

OBJECTIVE: This study aimed to assess whether the capacity of cochlear implant (CI) users to identify speech is determined by their capacity to perceive slow (< 20 Hz) temporal modulations. DESIGN: This was achieved by studying the correlation between (1) phoneme identification in quiet and in a steady-state or fluctuating (8 Hz) noises, and (2) amplitude-modulation detection thresholds (MDTs) at 8 Hz (i.e. slow temporal modulations). STUDY SAMPLE: Twenty-one CI users, unilaterally implanted with the same device, were tested in free field with their everyday clinical processor. RESULTS: Extensive variability across subjects was observed for both phoneme identification and MDTs. Vowel and consonant identification scores in quiet were significantly correlated with MDTs at 8 Hz (r = - 0.47 for consonants, r = - 0.44 for vowels; p < 0.05). When the masker was a steady-state noise, only consonant identification scores tended to correlate with MDTs at 8 Hz (r = - 0.4; p = 0.07). When the masker was a fluctuating noise, consonant and vowel identification scores were not significantly correlated with MDTs at 8 Hz. CONCLUSIONS: Sensitivity to slow amplitude modulations is correlated with vowel and consonant perception in CI users. However, reduced sensitivity to slow modulations does not entirely explain the limited capacity of CI recipients to understand speech in noise.

CPAP therapy prevents increase in blood pressure after upper airway surgery for obstructive sleep apnoea.

OBJECTIVE: The aim of this study was to investigate the efficacy of continuous positive airway pressure (CPAP) therapy following uvulopalatopharyngoplasty (UPPP) to prevent blood pressure (BP) elevation during sleep. METHODS: Sixteen normotensive patients with OSA were subjected to UPPP with or without septoplasty. These patients were instrumented for 24 h of ambulatory BP recording, polysomnography, nocturnal urinary catecholamine and pain evaluation using a visual analogue scale in the day prior to surgery (D-1), following the surgery (D+1) and 30 days later (D+30). For the D+1, the patients were divided into two groups: the without CPAP therapy group and the with CPAP therapy group. RESULTS: The apnoea-hypopnoea index (AHI) significantly increased in the patients without CPAP therapy compared with the D-1 (74 ± 23 vs. 35 ± 6 times/h, p < 0.05), and in the CPAP group, there was a significant reduction in the average AHI value to 14 ± 6 times/h, p < 0.01. During D+1, we observed an increase in the nocturnal systolic BP (10 %), diastolic BP (12 %) and heart rate (14 %) in the group without CPAP. These metrics were re-established in the CPAP group to values that were similar to those that were observed on the D-1. The absence of nocturnal dipping in the group without CPAP was followed by a significant increase in nocturnal norepinephrine (42 ± 12 µg/l/12 h) and epinephrine (8 ± 2 µg/l/12 h) levels compared with the D-1 (norepinephrine 17 ± 3; epinephrine 2 ± 0.3 µg/l/12 h, p < 0.001). In the patients who used the CPAP treatment, the nocturnal catecholamine levels were similar to D-1. The effectiveness of intravenous analgesic therapy was verified by a significant decrease in the pain scores in patients both with and without CPAP therapy. CONCLUSION: These data confirm an increase in the AHI on the night following UPPP with or without septoplasty. This increase promotes an absence of nocturnal dipping and a significant increase in urinary catecholamine levels. CPAP therapy was effective to prevent the transitory increase in BP.

Speech performance and sound localization abilities in Neurelec Digisonic® SP binaural cochlear implant users.

In this prospective study the outcome of the Digisonic® SP Binaural cochlear implant (CI), a device enabling electric stimulation of both cochleae by a single receiver, was evaluated in 14 postlingually deafened adults after 12 months of use. Speech perception was tested using French disyllabic words in quiet and in speech-shaped noise at +10 dB signal-to-noise ratio. Horizontal sound localization in quiet was tested using pink noise coming from 5 loudspeakers, from -90 to +90° along the azimuth. Speech scores in quiet were 76% (±19.5 SD) in the bilateral condition, 62% (±24 SD) for the better ear alone and 43.5% (±27 SD) for the poorer ear alone. Speech scores in noise were 60% (±27.5 SD), 46% (±28 SD) and 28% (±25 SD), respectively, in the same conditions. Statistical analysis showed a significant advantage of the bilateral use in quiet and in noise (p < 0.05 compared to the better ear). Significant spatial perception benefits such as summation effect (p < 0.05), head shadow effect (p < 0.0001) and squelch effect (p < 0.0005) were noted. Sound localization accuracy improved significantly when using the device in the bilateral condition with an average root mean square of 35°. Compared with published outcomes of usual bilateral cochlear implantation, this device could be a valuable alternative to two CIs. Prospective controlled trials, comparing the Digisonic SP Binaural CI with a standard bilateral cochlear implantation are mandatory to evaluate their respective advantages and cost-effectiveness.

Cardiovascular and thromboembolic risk factors in idiopathic sudden sensorineural hearing loss: a case-control study.

OBJECTIVE: The pathogenesis of idiopathic sudden sensorineural hearing loss (ISSHL) remains unknown, but vascular involvement is one of the main hypotheses. The main objective of this study was to investigate the association between ISSHL and cardiovascular and thromboembolic risk factors. STUDY DESIGN: Multicentric case-control study. METHODS: Ninety-six Caucasian patients with ISSHL and 179 sex- and age-matched controls were included. Patients were evaluated on the day of the inclusion and 1 week, 3 weeks and 3 months later. Clinical information concerning personal and familial cardiovascular and thromboembolic risk factors and concerning the ISSHL was collected. Blood samples were collected for genetic analysis of factor V Leiden and G20210A polymorphism in the factor II gene. The severity of the hearing loss was classified as mild (21-40 dB), moderate (41-70 dB), severe (71-90 dB) and profound or total (>90 dB). Hearing improvement was calculated as a relative improvement of hearing thresholds using the contralateral ear as baseline. RESULTS: Systolic blood pressure was higher in patients (130 ± 1.7 mm Hg) than in controls (124 ± 1.1 mm Hg, p = 0.003). The personal/familial history of cardiovascular events was also more prevalent in patients (p = 0.023 and p = 0.014, respectively), whereas no difference was found in the prevalence of personal cardiovascular risk factors (hypertension, diabetes mellitus, hyperlipidemia, smoking habits). There was no correlation between the audiogram type, the hearing outcome and the presence of cardiovascular risk factors. No significant difference was observed in the personal/familial history or in the presence of thromboembolic risk factors. The prothrombin and factor V mutations were uncommon in both patients and controls. The final hearing threshold was only correlated with the severity of the initial hearing loss (p < 0.001), but not influenced by the presence of vertigo, audiogram type, time elapsed from onset of ISSHL to hospitalization or failure of a previous oral therapy. Hearing stabilization was obtained at 21 days in 92% of patients. CONCLUSION: These results support the theory of vascular involvement as the etiology of some cases of ISSHL. The sole predictive factor of poor final hearing is the severity of the initial hearing loss.

Effects of spectral smearing and temporal fine structure degradation on speech masking release.

This study assessed the effects of spectral smearing and temporal fine structure (TFS) degradation on masking release (MR) (the improvement in speech identification in amplitude-modulated compared to steady noise observed for normal-hearing listeners). Syllables and noise stimuli were processed using either a spectral-smearing algorithm or a tone-excited vocoder. The two processing schemes simulated broadening of the auditory filters by factors of 2 and 4. Simulations of the early stages of auditory processing showed that the two schemes produced comparable excitation patterns; however, fundamental frequency (F0) information conveyed by TFS was degraded more severely by the vocoder than by the spectral-smearing algorithm. Both schemes reduced MR but, for each amount of spectral smearing, the vocoder produced a greater reduction in MR than the spectral-smearing algorithm, consistent with the effects of each scheme on F0 representation. Moreover, the effects of spectral smearing on MR produced by the two schemes were different for manner and voicing. Finally, MR data for listeners with moderate hearing loss were well matched by MR data obtained for normal-hearing listeners with vocoded stimuli, suggesting that impaired frequency selectivity alone may not be sufficient to account for the reduced MR observed for hearing-impaired listeners.

Middle ear and mastoid obliteration for cochlear implant in adults: indications and anatomical results.

AIM OF THE STUDY: To review indications, anatomical results, and complications of cochlear implant (CI) surgery in adults for which middle ear and mastoid obliterations were performed. PATIENTS AND METHODS: Thirty cases (26 patients, 4 bilaterally implanted) of 837 CI surgeries (3.5%) performed between January 2009 and December 2013 have been included in this retrospective study. The mean follow-up was 21 ± 18 months (mean ± SD, range 3-58). There were 11 males and 15 females. The mean age was 59 ± 19 years (range 35-82). All surgeries were performed with a single-stage technique including a canal wall down mastoidectomy with external auditory canal closure and mastoid obliteration with fat. A postoperative CT scan was performed in all cases. RESULTS: Etiologies of hearing loss were mainly chronic otitis with or without cholesteatoma in 24 cases. Other etiologies were meningitis with cochlear ossification in one case, progressive hearing loss in two cases, enlarged vestibular aqueduct in one case, temporal bone fracture with CSF leak in one case, and congenital aural atresia in one case. Four of those 30 cases were revision CI surgery for electrode array misplacement (one case with cochlear ossification) or extrusion from an open cavity (one case) and recurrent cholesteatomas (two cases). All surgeries were uneventful and performed in a single stage. The electrode array was inserted in the basal turn (29 cases) or in the middle turn (one case) of the cochlea. No complications were observed. Two cases of postoperative abdominal hematoma were drained under local anesthesia. A major failure of the CI device occurred 5 months after surgery. CONCLUSION: CI with mastoid and middle ear obliteration is a safe and effective technique for selected cases of cochlear implantation. Mastoid obliteration prevents from recurrent disease and lowering the facial ridge allows more space to manage extensive cochlear ossification or malformation.

Improvement of cognitive function after cochlear implantation in elderly patients.

IMPORTANCE: The association between hearing impairment and cognitive decline has been established; however, the effect of cochlear implantation on cognition in profoundly deaf elderly patients is not known. OBJECTIVE: To analyze the relationship between cognitive function and hearing restoration with a cochlear implant in elderly patients. DESIGN, SETTING, AND PARTICIPANTS: Prospective longitudinal study performed in 10 tertiary referral centers between September 1, 2006, and June 30, 2009. The participants included 94 patients aged 65 to 85 years with profound, postlingual hearing loss who were evaluated before, 6 months after, and 12 months after cochlear implantation. INTERVENTIONS: Cochlear implantation and aural rehabilitation program. MAIN OUTCOMES AND MEASURES: Speech perception was measured using disyllabic word recognition tests in quiet and in noise settings. Cognitive function was assessed using a battery of 6 tests evaluating attention, memory, orientation, executive function, mental flexibility, and fluency (Mini-Mental State Examination, 5-word test, clock-drawing test, verbal fluency test, d2 test of attention, and Trail Making test parts A and B). Quality of life and depression were evaluated using the Nijmegen Cochlear Implant Questionnaire and the Geriatric Depression Scale-4. RESULTS: Cochlear implantation led to improvements in speech perception in quiet and in noise (at 6 months: in quiet, 42% score increase [95% CI, 35%-49%; P < .001]; in noise, at signal to noise ratio [SNR] +15 dB, 44% [95% CI, 36%-52%, P < .001], at SNR +10 dB, 37% [95% CI 30%-44%; P < .001], and at SNR +5 dB, 27% [95% CI, 20%-33%; P < .001]), quality of life, and Geriatric Depression Scale-4 scores (76% of patients gave responses indicating no depression at 12 months after implantation vs 59% before implantation; P = .02). Before cochlear implantation, 44% of the patients (40 of 91) had abnormal scores on 2 or 3 of 6 cognition tests. One year after implant, 81% of the subgroup (30 of 37) showed improved global cognitive function (no or 1 abnormal test score). Improved mean scores in all cognitive domains were observed as early as 6 months after cochlear implantation. Cognitive performance remained stable in the remaining 19% of the participants (7 of 37). Among patients with the best cognitive performance before implantation (ie, no or 1 abnormal cognitive test score), 24% (12 of 50) displayed a slight decline in cognitive performance. Multivariate analysis to examine the association between cognitive abilities before implantation and the variability in cochlear implant outcomes demonstrated a significant effect only between long-term memory and speech perception in noise at 12 months (SNR +15 dB, P = .01; SNR +10 dB, P < .001; and SNR +5 dB, P = .02). CONCLUSIONS AND RELEVANCE: Rehabilitation of hearing communication through cochlear implantation in elderly patients results in improvements in speech perception and cognitive abilities and positively influences their social activity and quality of life. Further research is needed to assess the long-term effect of cochlear implantation on cognitive decline.

Mandibular advancement titration for obstructive sleep apnea: optimization of the procedure by combining clinical and oximetric parameters.

BACKGROUND: Oral appliances (OAs) have been used for the treatment of obstructive sleep apnea syndrome (OSAS), with different degrees of effectiveness having been shown in previous studies. But, in the absence of a consensual recommendation, the method of the determination of effective mandibular advancement varies from one study to another. STUDY OBJECTIVE: We prospectively evaluated an OA titration protocol based on a combined analysis of symptomatic benefit and oximetric recording to guide the progressive mandibular advancement. SETTING: University hospital sleep disorders center. PATIENTS: Forty patients with OSAS (mean [+/-SD] apnea-hypopnea index [AHI], 46 +/- 21 events per hour) found on baseline polysomnography, who were intolerant of nasal continuous positive airway pressure, completed all aspects of the study. METHODS: Two acrylic appliances connected by Herbst attachments were constructed. The mandible was advanced 1 mm every week until there was a resolution of the symptoms and a reduction in the oxygen desaturation index (ie, the number of desaturations yielding a > 3% fall in pulse oximetric saturation per hour of recording) [ODI] of <10 events per hour of recording or a maximum comfortable limit of advancement was obtained. The final response to OA was evaluated by full polysomnography recording. RESULTS: A complete response (ie, mean AHI, 5 +/- 3 events per hour; mean snoring reduction [SR], 91 +/- 13%; mean Epworth sleepiness scale [ESS] score, 5 +/- 3) was obtained in 63.6% of patients, and a limited response (ie, mean AHI, 21 +/- 11 events per hour; mean SR, 88 +/- 15%; mean ESS, 6 +/- 3) was obtained in 18.2% of patients. Twenty-five percent of mandibular advancements were motivated by an abnormal ODI (ie, 21 +/- 10 events per hour) despite resolution of the symptoms, while 20% were motivated by persistent symptoms with a normal ODI (ie, 6 +/- 2 events per hour). After a mean duration of 17 +/- 4 months, 34 patients declared that they had used the OA 5 +/- 2 days a week for 89 +/- 19% of their sleep time. CONCLUSIONS: A combination of the patient's subjective evaluation and oximetric score improves the effectiveness of the OA titration procedure.

Granular cell tumor of the palate: a case report.

Granular cell tumor (GCT) is an infrequent benign neoplasm, which Abrikosoff accurately described in 1926. GCT probably has a neural crest cell origin. We present the clinical and imaging findings in a 45-year-old woman with a GCT involving the palate. CT and MR imaging revealed perineural tumor spread along the greater and lesser palatine nerves. We emphasize the peculiarity of the palatine location and the perineural spread of GCTs.

Effect of cochlear damage on the detection of complex temporal envelopes.

Recent studies have demonstrated that the detection of complex temporal envelopes relies - at least partially - on the perception of a distortion component generated by a peripheral (cochlear) and/or central (post-cochlear) non-linearity. In the present study, first- and second-order amplitude modulation (AM) detection thresholds were obtained in normally hearing (NH) and hearing-impaired (HI) listeners using a 2-kHz pure-tone carrier. In both groups of listeners, first-order AM detection thresholds were measured for AM rates fm ranging between 4 and 87 Hz, and second-order AM detection thresholds were measured for second-order AM rates fm' ranging between 4 and 23 Hz, using a fixed first-order 'carrier' AM rate fm of 64 Hz. When the sound pressure level was adjusted in order to yield equal detectability in both groups for the 64-Hz first-order carrier modulation, (i) first-order AM detection thresholds for the HI listeners were normal at fm=87 Hz, and better-than-normal at fm=4 and 16 Hz, and (ii) second-order AM detection thresholds were identical at all modulation rates in NH and HI listeners. Similar results were obtained when the audibility of the 2-kHz pure-tone carrier was equated for both groups, i.e. when listeners were tested at the same sensation level. These results demonstrate clearly that cochlear damage has no effect on the detection of complex temporal envelopes, and indicate that the distortion component must be generated by a more central non-linearity than cochlear compression, transduction, or short-term adaptation.

Radiofrequency soft palate procedure in snoring: influence of energy delivered.

OBJECTIVE: We conducted a retrospective study to evaluate the influence of amount of energy delivered during radiofrequency procedure for soft palate reduction in snoring, to improve the cure rate. METHODS: Consecutive patients with chronic disruptive snoring presenting to our department were successively treated in an outpatient procedure. A visual analog scale was used to assess the severity of snoring by the bed partner and the pain by the patient, before treatment and after each treatment session. The soft palate was divided into 3 treatment sites: middle, lateral right, and lateral left. Any mucosal injury of the soft palate was classified as a complication. RESULTS: Forty-3 patients were classified into 2 groups according to energy assignment. The total amount of energy delivered was 1250 J in group 1 (n = 15) and 1500 J in group 2 (n = 28). Energy was predominantly distributed in the middle of the soft palate in group 1 (550 J) and group 2 (800 J). After each treatment session, the 1500-J delivery of radiofrequency energy (total per session) led to a better snoring grading reduction in comparison with the 1250-J delivery with a significant difference after 2 treatment sessions (P < 0.05). The mean pain score and the incidence rate of complications per treatment were not statistically different in comparing both groups. CONCLUSION: Better snoring scores can be expected by increasing radiofrequency energy applied to the soft palate. Further randomized long-term investigations are required to confirm that the cure rate can be improved when increasing energy with a suitable distribution and good clinical tolerance.

Benefits of the HiRes 120 coding strategy combined with the Harmony processor in an adult European multicentre study.

CONCLUSION: The Harmony processor was found to be reliable, comfortable and offered a substantially increased battery life compared with the previous generation processor. No significant improvement in speech understanding with HiRes was demonstrated from objective measures, but the majority of subjects showed a clear subjective preference for the combination HiRes 120/Harmony processor. OBJECTIVES: To evaluate experience with the Harmony™ sound processor, together with the HiRes 120 strategy. METHODS: Postlingually deafened adults implanted with a CII or HiRes 90K were included and divided into three groups: (1) experienced users using the Platinum body-worn processor; (2) experienced users who had been using other processors; (3) new users with the Harmony processor from first fitting. The latter group entered a randomized crossover protocol where half were initially fitted with HiRes and half with HiRes 120. The initial strategy was used for 3 months and the alternative for a further 3 months. Speech perception tests and questionnaires were performed. RESULTS: The study included 65 subjects. Implementing HiRes 120 was straightforward. The speech test group results did not show significant differences between HiRes and HiRes 120. However, the questionnaires showed significantly higher ratings for HiRes 120 in some instances. Subjects were highly satisfied with the Harmony processor.

Clinical evaluation of cochlear implant sound coding taking into account conjectural masking functions, MP3000™.

Efficacy of the SPEAK and ACE coding strategies was compared with that of a new strategy, MP3000™, by 37 European implant centers including 221 subjects. The SPEAK and ACE strategies are based on selection of 8-10 spectral components with the highest levels, while MP3000 is based on the selection of only 4-6 components, with the highest levels relative to an estimate of the spread of masking. The pulse rate per component was fixed. No significant difference was found for the speech scores and for coding preference between the SPEAK/ACE and MP3000 strategies. Battery life was 24% longer for the MP3000 strategy. With MP3000 the best results were found for a selection of six components. In addition, the best results were found for a masking function with a low-frequency slope of 50 dB/Bark and a high-frequency slope of 37 dB/Bark (50/37) as compared to the other combinations examined of 40/30 and 20/15 dB/Bark. The best results found for the steepest slopes do not seem to agree with current estimates of the spread of masking in electrical stimulation. Future research might reveal if performance with respect to SPEAK/ACE can be enhanced by increasing the number of channels in MP3000 beyond 4-6 and it should shed more light on the optimum steepness of the slopes of the masking functions applied in MP3000.

What breaks a melody: perceiving F0 and intensity sequences with a cochlear implant.

Pitch perception has been extensively studied using discrimination tasks on pairs of single sounds. When comparing pitch discrimination performance for normal-hearing (NH) and cochlear implant (CI) listeners, it usually appears that CI users have relatively poor pitch discrimination. Tasks involving pitch sequences, such as melody perception or auditory scene analysis, are also usually difficult for CI users. However, it is unclear whether the issue with pitch sequences is a consequence of sound discriminability, or if an impairment exists for sequence processing per se. Here, we compared sequence processing abilities across stimulus dimensions (fundamental frequency and intensity) and listener groups (NH, CI, and NH listeners presented with noise-vocoded sequences). The sequence elements were firstly matched in discriminability, for each listener and dimension. Participants were then presented with pairs of sequences, constituted by up to four elements varying on a single dimension, and they performed a same/different task. In agreement with a previous study (Cousineau et al., 2009) fundamental frequency sequences were processed more accurately than intensity sequences by NH listeners. However, this was not the case for CI listeners, nor for NH listeners presented with noise-vocoded sequences. Intensity sequence processing was, nonetheless, equally accurate in the three groups. These results show that the reduced pitch cues received by CI listeners do not only elevate thresholds, as previously documented, but also affect pitch sequence processing above threshold. We suggest that efficient sequence processing for pitch requires the resolution of individual harmonics in the auditory periphery, which is not achieved with the current generation of implants.

Intelligibility of interrupted and interleaved speech for normal-hearing listeners and cochlear implantees.

Speech intelligibility is degraded in the presence of a competing talker for cochlear implantees, presumably because of impaired tracking and integration of speech segments glimpsed in the masker valleys. This hypothesis was tested by assessing the intelligibility of periodically-interrupted bisyllables produced by a male and female talker, for normal-hearing listeners and implantees. A 4-Hz square-wave modulator with random phase was used to interrupt bisyllables from each talker. Stimuli were either presented alone (Experiment I) or interleaved (Experiment II: the two talkers were alternated). In Experiment I, the mean identification score for each voice was 88% for normal-hearing listeners and 35% for implantees. In Experiment II, the mean score corresponding to correct identification of both voices was 50% for normal-hearing listeners and 5% for implantees. Implantees identified at least one bisyllable among the two well above chance level but showed difficulties assigning it to the correct talker. This suggests that implantees can make use of partial information, but cannot track and integrate the non-adjacent components of interleaved speech as well as normal-hearing listeners. Additional results obtained with normal-hearing listeners tested with tone-vocoded syllables suggest that impaired tracking/integration for implantees stems from limited reception of spectral and temporal fine structure cues.

Speech perception performance for 100 post-lingually deaf adults fitted with Neurelec cochlear implants: Comparison between Digisonic® Convex and Digisonic® SP devices after a 1-year follow-up.

CONCLUSION: Patients implanted with the Digisonic® SP device showed better identification scores than those implanted with the Convex device, with skills continuing to improve over a longer time period. Technological improvements were beneficial in terms of speech perception in quiet. OBJECTIVE: To compare speech perception skills for post-lingually deaf patients implanted with a previous Neurelec device, the Digisonic® Convex, with those implanted with a more recent one, the Digisonic® SP, which provides more electrodes and a faster stimulation rate. METHODS: This was a retrospective study of 100 implanted patients, 45 with the Digisonic® Convex implant and 55 with the Digisonic® SP. Speech perception (dissyllabic words and sentences, in open set) was evaluated until 1 year after implantation. RESULTS: Patients fitted with the Digisonic® SP implant showed significantly better scores after 3, 6, and 12 months (mean scores: 53%, 62%, and 68% for words; 58%, 69%, and 75% for sentences) than those fitted with the Convex implant (34%, 42%, and 43% for words; 38%, 59%, and 51% for sentences). The improvement in speech perception after implantation for SP patients continued throughout the 12 months for words and 6 months for sentences, versus 6 months for words and 3 months for sentences for Convex patients.