Auditory Speech Discrimination Research Articles

The duration of intrauterine development influences discrimination of speech prosody in infants.

Auditory speech discrimination is essential for normal language development. Children born preterm are at greater risk of language developmental delays. Using functional near-infrared spectroscopy at term-equivalent age, the present study investigated early discrimination of speech prosody in 62 neonates born between week 23 and 41 of gestational age (GA). We found a significant positive correlation between GA at birth and neural discrimination of forward versus backward speech at term-equivalent age. Cluster analysis identified a critical threshold at around week 32 of GA, pointing out the existence of subgroups. Infants born before week 32 of GA exhibited a significantly different pattern of hemodynamic response to speech stimuli compared to infants born at or after week 32 of GA. Thus, children born before the GA of 32weeks are especially vulnerable to early speech discrimination deficits. To support their early language development, we therefore suggest a close follow-up and additional speech and language therapy especially in the group of children born before week 32 of GA.

Asymmetry of Auditory-Motor Speech Processing is Determined by Language Experience.

Speech processing relies on interactions between auditory and motor systems and is asymmetrically organized in the human brain. The left auditory system is specialized for processing of phonemes, whereas the right is specialized for processing of pitch changes in speech affecting prosody. In speakers of tonal languages, however, processing of pitch (i.e., tone) changes that alter word meaning is left-lateralized indicating that linguistic function and language experience shape speech processing asymmetries. Here, we investigated the asymmetry of motor contributions to auditory speech processing in male and female speakers of tonal and non-tonal languages. We temporarily disrupted the right or left speech motor cortex using transcranial magnetic stimulation (TMS) and measured the impact of these disruptions on auditory discrimination (mismatch negativity; MMN) responses to phoneme and tone changes in sequences of syllables using electroencephalography (EEG). We found that the effect of motor disruptions on processing of tone changes differed between language groups: disruption of the right speech motor cortex suppressed responses to tone changes in non-tonal language speakers, whereas disruption of the left speech motor cortex suppressed responses to tone changes in tonal language speakers. In non-tonal language speakers, the effects of disruption of left speech motor cortex on responses to tone changes were inconclusive. For phoneme changes, disruption of left but not right speech motor cortex suppressed responses in both language groups. We conclude that the contributions of the right and left speech motor cortex to auditory speech processing are determined by the functional roles of acoustic cues in the listener's native language.SIGNIFICANCE STATEMENT The principles underlying hemispheric asymmetries of auditory speech processing remain debated. The asymmetry of processing of speech sounds is affected by low-level acoustic cues, but also by their linguistic function. By combining transcranial magnetic stimulation (TMS) and electroencephalography (EEG), we investigated the asymmetry of motor contributions to auditory speech processing in tonal and non-tonal language speakers. We provide causal evidence that the functional role of the acoustic cues in the listener's native language affects the asymmetry of motor influences on auditory speech discrimination ability [indexed by mismatch negativity (MMN) responses]. Lateralized top-down motor influences can affect asymmetry of speech processing in the auditory system.

Binaural Hearing Rehabilitation Improves Speech Perception, Quality of Life, Tinnitus Distress, and Psychological Comorbidities.

To determine and compare the benefit of binaural hearing rehabilitation via cochlear implantation (CI) on speech perception, assessment of auditory abilities, tinnitus distress, health-related quality of life (HRQoL) and psychological comorbidities in patients suffering from asymmetric hearing loss (AHL) as well as bilaterally-deafened and sequentially bilaterally-implanted patients. 53 patients were implanted between 2011 and 2016. 24 AHL patients were implanted unilaterally, using a hearing aid on the other side. 29 bilaterally-deafened patients were sequentially implanted bilaterally. Speech perception, subjective hearing quality, HRQoL, tinnitus distress, anxiety, depressiveness, perceived stress level and coping abilities were evaluated before implantation, as well as 6 and 24 months postoperatively. Before CI, AHL and bilaterally-deaf patients showed significant differences regarding assessment of auditory abilities, speech discrimination, tinnitus distress and HRQoL. 24 months after CI both groups significantly improved in those scales. We could not find a significant difference between the groups after 2 years. Tinnitus distress significantly decreased 6 and 24 months postoperatively in both groups. This study demonstrates the long-term benefit of binaural hearing rehabilitation in AHL and bilaterally-deaf patients not only regarding speech perception but also HRQoL, tinnitus distress and subjective hearing quality. Bilaterally-deafened patients present lower scores preoperatively, but they did not differ from AHL patients 2 years after CI. Up to now, this is the first study evaluating the outcome of CI in AHL patients compared to bilaterally-implanted patients and demonstrating the benefit of binaural hearing rehabilitation in these specific groups.

Absence of neural speech discrimination in preterm infants at term-equivalent age

Children born preterm are at higher risk to develop language deficits. Auditory speech discrimination deficits may be early signs for language developmental problems. The present study used functional near-infrared spectroscopy to investigate neural speech discrimination in 15 preterm infants at term-equivalent age compared to 15 full term neonates. The full term group revealed a significantly greater hemodynamic response to forward compared to backward speech within the left hemisphere extending from superior temporal to inferior parietal and middle and inferior frontal areas. In contrast, the preterm group did not show differences in their hemodynamic responses during forward versus backward speech, thus, they did not discriminate speech from non-speech. Groups differed significantly in their responses to forward speech, whereas they did not differ in their responses to backward speech. The significant differences between groups point to an altered development of the functional network underlying language acquisition in preterm infants as early as in term-equivalent age.

Hearing improvement with softband and implanted bone-anchored hearing devices and modified implantation surgery in patients with bilateral microtia-atresia

ObjectiveTo evaluate auditory development and hearing improvement in patients with bilateral microtia-atresia using softband and implanted bone-anchored hearing devices and to modify the implantation surgery. MethodsThe subjects were divided into two groups: the softband group (40 infants, 3 months to 2 years old, Ponto softband) and the implanted group (6 patients, 6–28 years old, Ponto). The Infant-Toddler Meaning Auditory Integration Scale was used conducted to evaluate auditory development at baseline and after 3, 6, 12, and 24 months, and visual reinforcement audiometry was used to assess the auditory threshold in the softband group. In the implanted group, bone-anchored hearing devices were implanted combined with the auricular reconstruction surgery, and high-resolution CT was used to assess the deformity preoperatively. Auditory threshold and speech discrimination scores of the patients with implants were measured under the unaided, softband, and implanted conditions. ResultsTotal Infant-Toddler Meaning Auditory Integration Scale scores in the softband group improved significantly and approached normal levels. The average visual reinforcement audiometry values under the unaided and softband conditions were 76.75 ± 6.05 dB HL and 32.25 ± 6.20 dB HL (P < 0.01), respectively. In the implanted group, the auditory thresholds under the unaided, softband, and implanted conditions were 59.17 ± 3.76 dB HL, 32.5 ± 2.74 dB HL, and 17.5 ± 5.24 dB HL (P < 0.01), respectively. The respective speech discrimination scores were 23.33 ± 14.72%, 77.17 ± 6.46%, and 96.50 ± 2.66% (P < 0.01). ConclusionsUsing softband bone-anchored hearing devices is effective for auditory development and hearing improvement in infants with bilateral microtia-atresia. Wearing softband bone-anchored hearing devices before auricle reconstruction and combining bone-anchored hearing device implantation with auricular reconstruction surgery may bethe optimal clinical choice for these patients, and results in more significant hearing improvement and minimal surgical and anesthetic injury.

Revisiting the "enigma" of musicians with dyslexia: Auditory sequencing and speech abilities.

Previous research has suggested a link between musical training and auditory processing skills. Musicians have shown enhanced perception of auditory features critical to both music and speech, suggesting that this link extends beyond basic auditory processing. It remains unclear to what extent musicians who also have dyslexia show these specialized abilities, considering often-observed persistent deficits that coincide with reading impairments. The present study evaluated auditory sequencing and speech discrimination in 52 adults comprised of musicians with dyslexia, nonmusicians with dyslexia, and typical musicians. An auditory sequencing task measuring perceptual acuity for tone sequences of increasing length was administered. Furthermore, subjects were asked to discriminate synthesized syllable continua varying in acoustic components of speech necessary for intraphonemic discrimination, which included spectral (formant frequency) and temporal (voice onset time [VOT] and amplitude envelope) features. Results indicate that musicians with dyslexia did not significantly differ from typical musicians and performed better than nonmusicians with dyslexia for auditory sequencing as well as discrimination of spectral and VOT cues within syllable continua. However, typical musicians demonstrated superior performance relative to both groups with dyslexia for discrimination of syllables varying in amplitude information. These findings suggest a distinct profile of speech processing abilities in musicians with dyslexia, with specific weaknesses in discerning amplitude cues within speech. Because these difficulties seem to remain persistent in adults with dyslexia despite musical training, this study only partly supports the potential for musical training to enhance the auditory processing skills known to be crucial for literacy in individuals with dyslexia. (PsycINFO Database Record

Relación entre audición, alcoholismo y consumo de drogas en adultos jóvenes

There are research showing consequences for drug use or alcohol in auditory perception and speech discrimination. Even decreases were observed in some frequencies andauditory discrimination tasks. Despite this, there is no research involving the two variables. The aim is to analyze the relationship between alcohol and drug use, with thelevel of hearing and speech discrimination in young adults.It was a comparative–descriptive study, where 48 young people from 18 to 25 years (M = 21.5 years) from the city of Temuco (Chile) were selected for a deliberate sample; 72.9%women, organized into 3 subgroups, control group of 17 subjects without associated pathologies, group 1 consists of 13 alcoholic subjects finally composed of 18 individualdrug consumers group 2–alcoholism. Hearing evaluation instruments were applied as: otoscopy, tympanometry, audiometry and speech audiometry.The alcohol group showed decrease in the low frequencies of the left ear, however the alcohol-drug group, a sharp decrease in frequency. Logoaudiometry were inconclusive. Hearing decline observed in alcoholism and alcoholism groups– drugs, being the left ear in the altered group of alcoholics.

Infant auditory and audiovisual speech discrimination

Although infants are sensitive to the correspondence between auditory and visual speech cues, previous studies have not investigated whether infants can use this correspondence to improve speech perception in noise. This experiment used a modified observer-based psychoacoustic procedure to measure audiovisual benefit to speech discrimination in 6- to 8-month-old infants. Infants heard a single standard CV syllable repeatedly in a 65 dB A steady-state speech spectrum noise at 17 dB nHL (re: adult thresholds). Infants were trained to respond when they heard a new CV syllable. Some infants were tested with a vowel contrast; others were tested with a consonant contrast. Each infant completed either the auditory-only or audiovisual condition; when possible, they completed both conditions. In the auditory-only condition, a still image of the female talker remained on the screen throughout testing. In the audiovisual condition, a synchronous, congruent video of the talker played throughout testing. Preliminary results from 30 infants show a trend for better discrimination of audiovisual syllables than auditory-only syllables, suggesting visual speech improves infants’ perception of speech in noise and could be useful in speech and language learning. Differences in results for vowel contrasts, consonant contrasts, between-subjects analysis, and within-subjects analysis will be discussed.

Present and past: Can writing abilities in school children be associated with their auditory discrimination capacities in infancy?

Literacy acquisition is highly associated with auditory processing abilities, such as auditory discrimination. The event-related potential Mismatch Response (MMR) is an indicator for cortical auditory discrimination abilities and it has been found to be reduced in individuals with reading and writing impairments and also in infants at risk for these impairments. The goal of the present study was to analyze the relationship between auditory speech discrimination in infancy and writing abilities at school age within subjects, and to determine when auditory speech discrimination differences, relevant for later writing abilities, start to develop. We analyzed the MMR registered in response to natural syllables in German children with and without writing problems at two points during development, that is, at school age and at infancy, namely at age 1 month and 5 months. We observed MMR related auditory discrimination differences between infants with and without later writing problems, starting to develop at age 5 months–an age when infants begin to establish language-specific phoneme representations. At school age, these children with and without writing problems also showed auditory discrimination differences, reflected in the MMR, confirming a relationship between writing and auditory speech processing skills. Thus, writing problems at school age are, at least, partly grounded in auditory discrimination problems developing already during the first months of life.

MS-27 * THE IMPACT OF HYPOFRACTIONATED LINAC-BASED STEREOTACTIC RADIOSURGERY UPON EARLY AUDITORY FUNCTIONS IN THE TREATMENT OF VESTIBULAR SCHWANNOMAS

PURPOSE: To determine the impact of hypofractionated stereotactic radiotherapy (fSRT) scheme upon early auditory functions in the treatment of vestibular schwannomas (VSs). MATERIALS AND METHODS: 21 VS patients treated with a Linac-based frameless fSRT to 25 Gy in 5 daily fractions were retrospectively reviewed. Serial audiometry tests including auditory thresholds and speech discrimination (SD) were conducted prior to fSRT and then at regular intervals post-fSRT to determine the impact of our fSRT scheme on the patient's hearing function. Radiation doses to tumor (conformity index) and cochlea (dose to modiolus, maximal dose and V10) were measured for their impact on the auditory function. RESULTS: There was no tumor recurrence with a median follow-up of 17 months (range, 4-34 mos.). Gross tumor volume ranged from 0.15 to 6.1 cm3 with a mean of 1.47 cm3. Average conformity index (CI) of fSRT was 1.29 ± 0.32. The mean dose to the modiolus of the cochlea, mean of maximal dose and mean of V10 of the cochlea (volume of cochlea received 10 Gy or more) were 16.28 Gy, 23.52 Gy and 87.62%, respectively. There was 7- 8 dBs increase of pure tone average on lower (200, 500 and 1000 Hz) and higher frequency (4000 and 8000 Hz) after fSRT. The average of SD was decreased from 62% to 51% after treatment, which was not statistically significant. A weak correlation between the cochlea dose (modiolus dose and cochlea maximal dose) and the change of higher frequency pure tone average (4000 and 8000 Hz) was observed with a coefficient of 0.48. CONCLUSION: In contrast to literature report of a significant change of pure tone average in the first 12 months after Gamma knife treatment, we observed no significant pure tone average decline but SD decline after fSRT on VS patients.

Neurofibromatosis 2 invasion of the internal auditory canal wall: clinical significance.

To describe the infiltration of severe phenotype ("Wishart") neurofibromatosis type 2 (NF2)-related vestibular nerve schwannomas (VSs) into the internal auditory canal wall in contrast to sporadic VS and the milder ("Gardner") phenotype NF2-related VS. Retrospective case series involving microscopic examination and review of clinical history. Temporal bone laboratory, harboring 849 documented pairs of decalcified, formalin-fixed, celloidin-embedded, sectioned human temporal bones (hTBs) with clinical history. Histologic sections from 56 patients who had been treated by the House Clinic for VS and who had pledged their temporal bones were identified in the data base of the laboratory. Twenty-four hTBs were from individuals with NF2.Each series of sections was examined microscopically for evidence of invasion of the walls of the internal auditory canal (IAC), hearing thresholds, speech discrimination, score (SDS), and tumor recurrence. Infiltration of the walls of the IAC by small buds of VS was found in 17 of the 24 NF2 hTBs. The only 2 NF2 without invasion were from an elderly patient with the milder (Gardner) form of NF2. Ten of the 12 NF2 patients had undergone surgery for the removal of their tumor, but residual tumor remained in the bone surrounding the IAC. Invasive VS were associated with poorer hearing thresholds at 250, 500, 1,000, and 2,000 Hz and lower SDS score. A relationship between invasion and recurrence was not statistically significant. The majority of IAC tumors associated with the severe "Wishart" phenotype demonstrate bone invasion within the IAC. Invasion of bone was associated with poorer hearing. The invasive nature of NF2-associated tumors may partially explain their higher recurrence rate after resection. Surgeons managing NF2-related VS should be aware of the small infiltrations of the wall of the IAC when removing these tumors to minimize recurrence.

Tecnologías auditivas actuales y desarrollo gramatical infantil

The new auditory technologies provide deaf children with auditory speech discrimination that was unthinkable a few years ago. The aim of this study was to analyze grammatical development in deaf children using new auditory technologies, and to confirm which variables account for intersubject differences.We evaluated 32 children (aged 3-7 years) with bilateral and congenital or pre-speech deafness and hearing loss greater than 70dB, who used digital hearing aids or cochlear implants. The Reynell Developmental Language Scales III was administered in each child. The results showed that only 30% of the participants demonstrated age-appropriate language skills.In language comprehension, sentences connecting more than 2 elements caused difficulties, which were greater when these sentences were passive and subordinate. In expressive language, a grammatical level equivalent to that in 3-year-olds caused the most difficulty for most of the participants. Expressive language related to inflections of past tense and third person verbs, and plural noun construction also caused difficulties. The most explanatory variable was age at implantation and at prosthesis fitting in deaf children. The family's sociocultural level was also important.

SIG 7 Perspectives Vol. 18, No. 1, October 2011

SIG 7 Perspectives Vol. 18, No. 1, October 2011

Auditory discrimination as a condition for E-learning based Speech Therapy: A proposal for an auditory discrimination test (ADT) for adult dysarthric speakers

Background Web based speech training for dysarthric speakers, such as E-learning based Speech Therapy (EST), puts considerable demands on auditory discrimination abilities. Aims To discuss the development and the evaluation of an auditory discrimination test (ADT) for the assessment of auditory speech discrimination skills in Dutch adult dysarthric speakers as a prelude to EST. Method Five ADT subtests were developed, each addressing a vital speech dimension in speech therapy: articulation (segmental elements), intensity, overall pitch, speech rate and intonation. A healthy control group of 36 participants performed a ‘same-different task’ in each subtest. ADT items yielding scores of at least 80% but below 100% correctly responding healthy controls were considered sensitive to diminished auditory discrimination. Subsequently, the ADT was carried out by 14 neurological patients with dysarthric speech and 14 matched healthy controls. Score percentages, sensitivity indices and reaction times (ms) on only sensitive items were compared. Results The majority of the ADT items met the ‘minimal 80% to below 100% criterion’ in the healthy control group. The neurological participants performed lower on all outcome measures across all subtests than the healthy controls, although not all of these differences achieved statistical significance. Conclusions The results of the healthy control group show that the majority of the ADT items meet our criterion for sensitivity to diminished auditory discrimination. The poorer performance of dysarthric patients across all subtests supports the sensitivity of the ADT. However, further research involving larger and more homogeneous groups of neurological patients is required. Learning outcomes: Readers will be encouraged to (1) identify potential factors that may hinder web based speech training and (2) estimate the value of assessing auditory discrimination skills as a vital condition for (web based) speech training in dysarthric patients.

Auditory Training and Adult Rehabilitation: A Critical Review of the Evidence

Auditory Training (AT) describes a regimen of varied listening exercises designed to improve an individual’sability to perceive speech. The theory of AT is based on brain plasticity (the capacity of neurones in the centralauditory system to alter their structure and function) in response to auditory stimulation. The practice ofrepeatedly listening to the speech sounds included in AT exercises is believed to drive the development of moreefficient neuronal pathways, thereby improving auditory processing and speech discrimination. This criticalreview aims to assess whether auditory training can improve speech discrimination in adults with mild-moderateSNHL. The majority of patients attending Audiology services are adults with presbyacusis and it is thereforeimportant to evaluate evidence of any treatment effect of AT in aural rehabilitation. Ideally this review wouldseek to appraise evidence of neurophysiological effects of AT so as to verify whether it does induce change inthe CAS. However, due to the absence of such studies on this particular patient group, the outcome measure ofspeech discrimination, as a behavioural indicator of treatment effect is used instead. A review of availableresearch was used to inform an argument for or against using AT in rehabilitative clinical practice. Six studieswere identified and although the preliminary evidence indicates an improvement gained from a range of ATparadigms, the treatment effect size was modest and there remains a lack of large-sample RCTs. Futureinvestigation into the efficacy of AT needs to employ neurophysiological studies using auditory evokedpotentials in hearing-impaired adults in order to explore effects of AT on the CAS.

Auditory Training and Adult Rehabilitation: A Critical Review of the Evidence

Auditory Training (AT) describes a regimen of varied listening exercises designed to improve an individual’sability to perceive speech. The theory of AT is based on brain plasticity (the capacity of neurones in the centralauditory system to alter their structure and function) in response to auditory stimulation. The practice ofrepeatedly listening to the speech sounds included in AT exercises is believed to drive the development of moreefficient neuronal pathways, thereby improving auditory processing and speech discrimination. This criticalreview aims to assess whether auditory training can improve speech discrimination in adults with mild-moderateSNHL. The majority of patients attending Audiology services are adults with presbyacusis and it is thereforeimportant to evaluate evidence of any treatment effect of AT in aural rehabilitation. Ideally this review wouldseek to appraise evidence of neurophysiological effects of AT so as to verify whether it does induce change inthe CAS. However, due to the absence of such studies on this particular patient group, the outcome measure ofspeech discrimination, as a behavioural indicator of treatment effect is used instead. A review of availableresearch was used to inform an argument for or against using AT in rehabilitative clinical practice. Six studieswere identified and although the preliminary evidence indicates an improvement gained from a range of ATparadigms, the treatment effect size was modest and there remains a lack of large-sample RCTs. Futureinvestigation into the efficacy of AT needs to employ neurophysiological studies using auditory evokedpotentials in hearing-impaired adults in order to explore effects of AT on the CAS.

Gamma Knife Surgery of Vestibular Schwannomas

Determine which variables are correlated with early hearing changes after gamma knife surgery of vestibular schwannomas (VSs). Prospective clinical study of hearing outcomes, radiation dosimetry, conformity, and tumor size of all sporadic unilateral VS patients treated between June 2000 and July 2009. Tertiary referral center. : Fifty-nine VS patients with at least 6 months of follow-up data were studied. Audiometry and imaging were performed to determine auditory thresholds, speech discrimination, and tumor size. Radiation doses to 5 volumes were measured. Pretreatment and posttreatment comparisons were performed with regard to change in tumor size; radiation dose to specific volumes including the internal auditory canal, cochlea, basal turn of the cochlea, and modiolus; and conformity of the treatment. The mean follow-up was 63.76 months (standard deviation, ±29.02 mo; range, 9-109 mo). The median follow-up was 65.5 months. A statistically significant association between maximum radiation dose to the cochlea volume and 3-frequency pure-tone average in patients starting with 50 dB or lesser PTA3 was demonstrated using linear regression analysis. Longitudinal changes in hearing occur over time, with the largest changes seen in the first 12 months after treatment. With our study outcomes as basis, limiting the dose of radiation to the cochlea to no more than 4 Gy would likely reduce vascular injury to the stria vascularis and improve hearing outcomes. Shielding the cochlea during the treatment planning process would be one mechanism to accomplish this goal.

Otosclerosis: Mid-Term Results of Cochlear Implantation

Introduction: Constant histological changes in otosclerosis lead to progressive hearing loss which may end up in a profound hearing loss and then be treated by means of cochlear implants. These progressive changes could be followed by changes in cochlear implants fitting and speech discrimination results over the years. Objectives: The aim of the study is to correlate the progressive histological changes to the cochlear implant clinical outcomes (fitting and speech discrimination results). Also main complications (facial nerve stimulation and difficulties at insertion) and new complications will be discussed. Design: A 5-year prospective case-control study was performed in order to compare cochlear implant results in otosclerosis patients to those in a matched-pair control group. Materials and Methods: Fifteen otosclerosis patients were followed throughout the study. Preoperatively temporal bone high-resolution computed tomography, electrically evoked auditory brainstem responses and speech discrimination tests were performed in order to select the patients to be implanted. Results: Not only difficulties with electrode guide insertion were reported, but also difficulties with fitting over the years, due to increasing difficulties to spread the electrical stimuli, which provokes increasing thresholds, maximum comfort levels and charges needed to stimulate hearing cells in basal and medial turn electrodes (p < 0.05), which required deactivating some basal and medial turn electrodes in order to improve cochlear implant effectiveness. The results demonstrated no statistical differences in speech discrimination in otosclerosis patients compared to the control group (p > 0.05). Several complications were reported: facial nerve stimulation (7.14%) and sudden episodes of tinnitus and headaches (14.28%). Conclusions: Although progressive histological changes in otosclerosis lead to increasing thresholds, maximum comfort levels and charges needed to stimulate hearing cells, speech discrimination results support the cochlear implantation in otosclerosis.

Auditory Perception and Speech Discrimination After Cochlear Implantation in Patients with Connexin 26 (GJB2) Gene-Related Deafness

Auditory perception and speech discrimination among pediatric cochlear implantees may vary because of underlying deafness etiology, including connexin 26 (GJB2) gene-related deafness. Preliminary data suggest pathologic changes due to GJB2 mutations do not affect the spiral ganglion cells, which are stimulated by the cochlear implant. The survival of the spiral ganglion cells is believed to be an important determinant of outcome after surgery. Patients with GJB2-related deafness may therefore have enhanced prospects for good speech discrimination after implantation. In an observational cohort study, GJB2 mutation analysis was performed using polymerase chain reaction amplification and direct sequencing on 31 prelingually deaf pediatric cochlear implantees, of which there were 30 with nonsyndromic deafness of unknown etiology, and one with keratitis-ichthyosis-deafness syndrome. Speech discrmination was assessed prospectively when they had reached postoperative year 3 using the IOWA Matrix Level B Sentences test and Glendonald Auditory Screening Procedure (GASP), with both patients and assessors blind to GJB2 status. Eleven patients had GJB2-related deafness and 20 patients had GJB2-unrelated deafness. IOWA Matrix scores were higher in patients with GJB2-related deafness but did not reach statistical significance. However, GASP scores were statistically significantly higher in patients with GJB2-related deafness (median word score, 92%; median sentence score, 80%), compared with those of patients with GJB2-unrelated deafness (median word score, 63%; median sentence score, 45%; word score, p = 0.037; sentence score, p = 0.045). Ordinal logistic regression analysis on IOWA Matrix and GASP sentence scores found better statistically significant scores in patients with GJB2-related deafness (p < 0.05) after adjustment for confounding variables. Pediatric cochlear implantees with GJB2-related deafness appear to have equal or better speech discrimination compared with a group of prelingually deaf children with deafness of unknown etiology.

Gamma knife radiosurgery for acoustic neuromas performed by a neurotologist: early experiences and outcomes.

To assess early outcomes after Gamma knife radiosurgery of acoustic neuromas and other skull base tumors. Gamma knife radiosurgery is one of the available methods to treat acoustic neuromas, in addition to micro-surgical resection. Neuro-otologists have long been associated with microsurgical resection of these tumors; however, the application of Gamma knife radiosurgery to the treatment of these tumors by neuro-otologists has not been previously described. Acoustic Neuroma and Skull Base Surgery Program / Tertiary Referral Center. STUDY DESIGN/PATIENTS/INTERVENTION: Prospective clinical study of all patients treated by the senior author and our gamma knife team beginning in June 2000. Preoperative MRI, audiometry, vestibular testing and facial nerve electromyography were completed. At six-month intervals postoperatively, audiometry, caloric testing and MRI were performed to determine thresholds and speech discrimination ability, vestibular function, and the size of the tumor. From June 2000 until March 2004, 38 patients were treated, and these included 33 acoustic neuromas, two meningiomas, one glomus jugulare tumor, and two facial neuromas. Greater than 36 month follow-up was available in 7 patients, > 24 months in 24, > 12 months in 31, and > 6 months in 34 patients. Statistically significant reduction in tumor size was seen over time, and tumor control was achieved in all but two patients. Various patterns of changes in auditory function, both in threshold and speech discrimination were observed in either positive or negative directions. Preliminary experience with Gamma knife radiosurgery indicates that this treatment method represents another option for neuro-otologists to use in managing patients with skull base tumors.