Kristin Uhler

Longitudinal infant speech perception in young cochlear implant users.

PURPOSE This paper presents longitudinal case studies of children who received (cochlear implants) CIs and a controlled sample of children with normal hearing (NH). Phoneme discrimination (i.e., /sa-ma/, /a-i/, /a-u/, /u-i/, /ta-da/, /pa-ka/) was assessed prior to receiving CIs and monthly for 3 mo following CI activation. RESEARCH DESIGN Case studies. STUDY SAMPLE Three cochlear implant recipients and seven NH control participants were recruited through the University of Colorado Hospital and the University of Colorado, Boulder. DATA COLLECTION AND ANALYSIS The study utilized the visual reinforcement audiometry and interactive play assessment of speech pattern contrasts (VRASPAC) algorithm. A comparison of scoring was conducted using Cohens kappa to determine interrater reliability. RESULTS Findings from this study revealed that CI recipients could discriminate at least three out of five phoneme contrasts at mastery level (≥90%) by 2 mo of device use. None of the CI recipients reached mastery prior to implantation. Following 3 mo of CI use there was no difference in contrast discrimination performance between the CI users and their NH age-matched peers (with the exception of /pa-ka/ for one CI user. CONCLUSIONS The CI users in this case study, who were implanted between 12 and 16 mo of age, were able to master the phoneme contrasts regardless of bilateral or unilateral CI, socioeconomic status, or language spoken at home.

Otologics Active Middle Ear Implants

This article describes outcomes for the Otologics active middle ear implant for the semi-implantable and fully implantable (Carina, Otologics LLC, Boulder, CO) devices. Inclusion and exclusion criteria are reported in detail for surgical and audiologic management. Results from the clinical trial demonstrated no change for unaided air and bone conduction thresholds and no significant change in monosyllabic word scores or sentences in noise. Experiments are reported for conductive and mixed types of hearing losses in animal and human cadaveric models. These devices are in their infancy, and further study is needed to better identify candidates and develop appropriate expectations.

A Tutorial on Auditory Neuropathy/Dyssynchrony for the Speech-Language Pathologist and Audiologist

This article presents information about developmental outcomes of children with auditory neuropathy/auditory dyssynchrony (AN). Colorado data on the number of children screened and the number of children identified with unilateral and bilateral AN will be described. Descriptive information about the percent of children with AN with cognitive disability and disabilities other than hearing loss will be presented. Language outcomes of children with normal cognitive development will be presented. This article will also provide information about etiologies and audiological information of children with AN. It includes assessment tools that have been useful in decision making for children with AN.

Method of Speech Stimulus Presentation Impacts Pediatric Speech Recognition: Monitored Live Voice Versus Recorded Speech.

Objective: To characterize the potential differences in speech understanding performance on word and sentence tests assessed using live voice and recorded speech measures for pediatric cochlear implant (CI) recipients. Study Design: This clinical study used a combination of retrospective and prospective study designs exploring within-subject performance for recorded versus monitored-live-voice presentation methods on pediatric word and sentence measures. Methods: Word and/or sentence recognition was obtained for 29 pediatric CI recipients using both recorded stimuli and monitored-live-voice (MLV) within a single-test session with a single experimenter for each session. The difference score was calculated for word and sentence measures allowing a comparison across conditions. Setting: Ambulatory. Patients: Pediatric patients aged 4 to 17 years. Intervention(s): Cochlear implants. Main Outcome Measure(s): Speech recognition testing. Results: There was a significant difference between recorded and MLV speech understanding with mean recorded word scores being 13-percentage points lower than those obtained via MLV. Conclusions: The results of this project suggest that the use of MLV for the assessment of speech perception in the pediatric Audiology clinic may overinflate childrens performance and thereby runs the risk of failing to identify poorer or at-risk performance.

Speech perception comparisons using an implanted and an external microphone in existing cochlear implant users.

Objective To compare the speech understanding abilities of cochlear implant listeners using 2 microphone technologies, the Otologics fully implantable Carina and the Cochlear Freedom microphones. Study Design Feasibility study using direct comparison of the 2 microphones, nonrandomized and nonblinded within case studies. Setting Tertiary referral center hospital outpatient clinic. Patients Four subjects with greater than 1 year of unilateral listening experience with the Freedom Cochlear Implant and a CNC word score higher than 40%. Intervention A Carina microphone coupled to a percutaneous plug was implanted on the ipsilateral side of the cochlear implant. Two months were allowed for healing before connecting to the Carina microphone. The percutaneous plug was connected to a body worn external processor with output leads inserted into the auxiliary port of the Freedom processor. Subjects were instructed to use each of the 2 microphones for half of their daily implant use. Main Outcome Measures Aided pure tone thresholds, consonant-nucleus-consonant (CNC), Bamford-Kowel-Bench Speech in Noise test (BKN-SIN), and Abbreviated Profile of Hearing Aid Benefit. Results All subjects had sound perceptions using both microphones. The loudness and quality of the sound was judged to be poorer with the Carina in the first 2 subjects. The latter 2 demonstrated essential equivalence in the second two listeners, with the exception of the Abbreviated Profile of Hearing Aid Benefit reporting greater percentage of problems for the Carina in the background noise situation for subject 0011-003PP. CNC word scores were better with the Freedom than the Carina in all 4 subjects. The latter 2 showed improved speech perception abilities with the Carina, compared with the first 2. The BKB-SIN showed consistently better results with the Freedom in noise. Conclusion Early observations indicate that it is potentially feasible to use the fully implanted Carina microphone with the Freedom Cochlear Implant. The authors would anticipate that outcomes would improve as more knowledge is gained in signal processing and with the fabrication of an integrated device.

Refining Stimulus Parameters in Assessing Infant Speech Perception Using Visual Reinforcement Infant Speech Discrimination: Sensation Level.

BACKGROUND Speech perception measures have long been considered an integral piece of the audiological assessment battery. Currently, a prelinguistic, standardized measure of speech perception is missing in the clinical assessment battery for infants and young toddlers. Such a measure would allow systematic assessment of speech perception abilities of infants as well as the potential to investigate the impact early identification of hearing loss and early fitting of amplification have on the auditory pathways. PURPOSE To investigate the impact of sensation level (SL) on the ability of infants with normal hearing (NH) to discriminate /a-i/ and /ba-da/ and to determine if performance on the two contrasts are significantly different in predicting the discrimination criterion. RESEARCH DESIGN The design was based on a survival analysis model for event occurrence and a repeated measures logistic model for binary outcomes. The outcome for survival analysis was the minimum SL for criterion and the outcome for the logistic regression model was the presence/absence of achieving the criterion. Criterion achievement was designated when an infants proportion correct score was >0.75 on the discrimination performance task. STUDY SAMPLE Twenty-two infants with NH sensitivity participated in this study. There were 9 males and 13 females, aged 6-14 mo. DATA COLLECTION AND ANALYSIS Testing took place over two to three sessions. The first session consisted of a hearing test, threshold assessment of the two speech sounds (/a/ and /i/), and if time and attention allowed, visual reinforcement infant speech discrimination (VRISD). The second session consisted of VRISD assessment for the two test contrasts (/a-i/ and /ba-da/). The presentation level started at 50 dBA. If the infant was unable to successfully achieve criterion (>0.75) at 50 dBA, the presentation level was increased to 70 dBA followed by 60 dBA. Data examination included an event analysis, which provided the probability of criterion distribution across SL. The second stage of the analysis was a repeated measures logistic regression where SL and contrast were used to predict the likelihood of speech discrimination criterion. RESULTS Infants were able to reach criterion for the /a-i/ contrast at statistically lower SLs when compared to /ba-da/. There were six infants who never reached criterion for /ba-da/ and one never reached criterion for /a-i/. The conditional probability of not reaching criterion by 70 dB SL was 0% for /a-i/ and 21% for /ba-da/. The predictive logistic regression model showed that children were more likely to discriminate the /a-i/ even when controlling for SL. CONCLUSIONS Nearly all normal-hearing infants can demonstrate discrimination criterion of a vowel contrast at 60 dB SL, while a level of ≥70 dB SL may be needed to allow all infants to demonstrate discrimination criterion of a difficult consonant contrast.

Pediatric minimum speech test battery

Background: Assessment of patient outcomes and documentation of treatment efficacy serves as an essential component of (re)habilitative audiology; however, no standardized protocol exists for the assessment of speech perception abilities for children with hearing loss. This presents a significant challenge in tracking performance of children who utilize various hearing technologies for within‐subjects assessment, between‐subjects assessment, and even across different facilities. Purpose: The adoption and adherence to a standardized assessment protocol could help facilitate continuity of care, assist in clinical decision making, allow clinicians and researchers to define benchmarks for an aggregate clinical population, and in time, aid with patient counseling regarding expectations and predictions regarding longitudinal outcomes. Design: The Pediatric Minimum Speech Test Battery (PMSTB) working group—comprised of clinicians, scientists, and industry representatives—commenced in 2012 and has worked collaboratively to construct the first PMSTB, which is described here. Conclusions: Implementation of the PMSTB in clinical practice and dissemination of associated data are both critical for achieving the next level of success for children with hearing loss and for elevating pediatric hearing health care ensuring evidence‐based practice for (re)habilitative audiology.

Air-Bone Gaps Contribute to Functional Hearing Preservation in Cochlear Implantation.

Objective: To examine the incidence and effect of postoperative air-bone gaps in subjects who received cochlear implants for the purpose of hearing preservation. Study Design: Prospective, multicenter, nonrandomized, repeated measures within subject design. Setting: Ten tertiary care institutions. Patients: Fifty adults participating in a multicenter clinical trial of the Cochlear Nucleus Hybrid implant system. Intervention(s): Cochlear implantation with Hybrid L24 electrode. Audiometric testing including air and bone conductive thresholds and tympanometry preoperatively and at multiple time points postoperatively for 1 year. Main Outcome Measure(s): Average air-bone gaps (ABG) and percentage of patients with ABGs (≥15 dB HL) measured for each time point for 1 year postoperatively at 250, 500, and 1000 Hz. Correlation of tympanograms and ABGs. Results: The mean ABGs at 250, 500, and 1000 Hz increased postoperatively (p <0.05). The percentage of patients found to have an ABG (≥15 dB HL) also increased postoperatively (p <0.05). ABGs persisted and were present at 1 year in >60% of patients at 250 Hz, in >38% at 500 Hz, and in >50% at 1000 Hz in those with residual hearing. No significant relationships were found between abnormal tympanograms and ABG. Conclusion: The incidence of ABGs postoperatively is higher than previously expected and does not correlate to abnormalities on tympanometry. ABGs can adversely affect the fitting of postoperative residual hearing and associated functional benefit. Additionally, intraoperative strategies should be used to potentially reduce ABGs, and bone conduction thresholds should be measured postoperatively.

Long-Term Outcome Data in Patients following One Year's Use of a Fully Implantable Active Middle Ear Implant.

This study examined the safety and efficacy of a fully implantable active middle ear (AMEI) system. Outcome measures assessed AMEI performance compared with an optimally fitted conventional hearing aid (CHA). Fifty adults with stable, symmetric moderate-to-severe sensorineural hearing loss were implanted at 9 ambulatory settings. Consonant-Nucleus-Consonant (CNC) words, Bamford-Kowel-Bench Speech in Noise test (BKB-SIN), Abbreviated Profile of Hearing Aid Benefit (APHAB), and unaided hearing thresholds in the implanted ear were compared to baseline measures obtained using a personal CHA. Changes in thresholds were observed from pre- to 12-month postoperative assessments. CNC word scores decreased (within 10%), and the BKB-SIN showed no change from pre- to 12-month postoperative time points. The APHAB revealed improvement. Findings suggest no difference in performance between an appropriately fit CHA and the AMEI at 12 months. This study indicates AMEIs have the potential to help individuals who choose not to use CHAs.

The relationship between mismatch response and the acoustic change complex in normal hearing infants

OBJECTIVE To examine the utility of the mismatch response (MMR) and acoustic change complex (ACC) for assessing speech discrimination in infants. METHODS Continuous EEG was recorded during sleep from 48 (24 male, 20 female) normally hearing aged 1.77 to -4.57 months in response to two auditory discrimination tasks. ACC was recorded in response to a three-vowel sequence (/i/-/a/-/i/). MMR was recorded in response to a standard vowel, /a/, (probability 85%), and to a deviant vowel, /i/, (probability of 15%). A priori comparisons included: age, sex, and sleep state. These were conducted separately for each of the three bandpass filter settings were compared (1-18, 1-30, and 1-40 Hz). RESULTS A priori tests revealed no differences in MMR or ACC for age, sex, or sleep state for any of the three filter settings. ACC and MMR responses were prominently observed in all 44 sleeping infants (data from four infants were excluded). Significant differences observed for ACC were to the onset and offset of stimuli. However, neither group nor individual differences were observed to changes in speech stimuli in the ACC. MMR revealed two prominent peaks occurring at the stimulus onset and at the stimulus offset. Permutation t-tests revealed significant differences between the standard and deviant stimuli for both the onset and offset MMR peaks (p < 0.01). The 1-18 Hz filter setting revealed significant differences for all participants in the MMR paradigm. CONCLUSION Both ACC and MMR responses were observed to auditory stimulation suggesting that infants perceive and process speech information even during sleep. Significant differences between the standard and deviant responses were observed in the MMR, but not ACC paradigm. These findings suggest that the MMR is sensitive to detecting auditory/speech discrimination processing. SIGNIFICANCE This paper identified that MMR can be used to identify discrimination in normal hearing infants. This suggests that MMR has potential for use in infants with hearing loss to validate hearing aid fittings.