Neural Correlates of Individual Differences in Speech-in-Noise Performance in a Large Cohort of Cochlear Implant Users.

OBJECTIVES: Understanding speech-in-noise (SiN) is a complex task that recruits multiple cortical subsystems. Individuals vary in their ability to understand SiN. This cannot be explained by simple peripheral hearing profiles, but recent work by our group ( Kim et al. 2021 , Neuroimage ) highlighted central neural factors underlying the variance in SiN ability in normal hearing (NH) subjects. The present study examined neural predictors of SiN ability in a large cohort of cochlear-implant (CI) users. DESIGN: We recorded electroencephalography in 114 postlingually deafened CI users while they completed the California consonant test: a word-in-noise task. In many subjects, data were also collected on two other commonly used clinical measures of speech perception: a word-in-quiet task (consonant-nucleus-consonant) word and a sentence-in-noise task (AzBio sentences). Neural activity was assessed at a vertex electrode (Cz), which could help maximize eventual generalizability to clinical situations. The N1-P2 complex of event-related potentials (ERPs) at this location were included in multiple linear regression analyses, along with several other demographic and hearing factors as predictors of SiN performance. RESULTS: In general, there was a good agreement between the scores on the three speech perception tasks. ERP amplitudes did not predict AzBio performance, which was predicted by the duration of device use, low-frequency hearing thresholds, and age. However, ERP amplitudes were strong predictors for performance for both word recognition tasks: the California consonant test (which was conducted simultaneously with electroencephalography recording) and the consonant-nucleus-consonant (conducted offline). These correlations held even after accounting for known predictors of performance including residual low-frequency hearing thresholds. In CI-users, better performance was predicted by an increased cortical response to the target word, in contrast to previous reports in normal-hearing subjects in whom speech perception ability was accounted for by the ability to suppress noise. CONCLUSIONS: These data indicate a neurophysiological correlate of SiN performance, thereby revealing a richer profile of an individual's hearing performance than shown by psychoacoustic measures alone. These results also highlight important differences between sentence and word recognition measures of performance and suggest that individual differences in these measures may be underwritten by different mechanisms. Finally, the contrast with prior reports of NH listeners in the same task suggests CI-users performance may be explained by a different weighting of neural processes than NH listeners.

Validation of the Iowa Test of Consonant Perception.

Speech perception (especially in background noise) is a critical problem for hearing-impaired listeners and an important issue for cognitive hearing science. Despite a plethora of standardized measures, few single-word closed-set tests uniformly sample the most frequently used phonemes and use response choices that equally sample phonetic features like place and voicing. The Iowa Test of Consonant Perception (ITCP) attempts to solve this. It is a proportionally balanced phonemic word recognition task designed to assess perception of the initial consonant of monosyllabic consonant-vowel-consonant (CVC) words. The ITCP consists of 120 sampled CVC words. Words were recorded from four different talkers (two female) and uniformly sampled from all four quadrants of the vowel space to control for coarticulation. Response choices on each trial are balanced to equate difficulty and sample a single phonetic feature. This study evaluated the psychometric properties of ITCP by examining reliability (test-retest) and validity in a sample of online normal-hearing participants. Ninety-eight participants completed two sessions of the ITCP along with standardized tests of words and sentence in noise (CNC words and AzBio sentences). The ITCP showed good test-retest reliability and convergent validity with two popular tests presented in noise. All the materials to use the ITCP or to construct your own version of the ITCP are freely available [Geller, McMurray, Holmes, and Choi (2020). https://osf.io/hycdu/].

Laser plume containment during flexible transnasal laryngoscopy.

Objective: To evaluate a negative pressure microenvironment designed to contain laser plume during flexible transnasal laryngoscopy. Methods: The Negative Pressure Face Shield (NPFS) was previously reported as well tolerated with initial use on 30 patients. Diagnostic transnasal laryngoscopy was performed on an additional 108 consecutive patients who were evaluated by questionnaires and sequential pulse oximetry. Further study addressed operative transnasal potassium-titanyl-phosphate (KTP) laser laryngoscopy with biopsy done on four patients employing the NPFS. Results: The previously described NPFS version 3 (v.3), a transparent acrylic barrier with two anterior instrumentation ports, was modified by repositioning the side suction port closer to the level of the nose and deepening the lateral sides, squaring off the lower projection. A post-procedure questionnaire employing a 5-point Likert scale ranging from no symptoms (rating of 1) to intolerable (rating of 5) identified excellent patient tolerance of the new design (v.4), among 22 patients evaluated and similar in the comparison to the 116 patients using version 3. Among the 138 patients analyzed, only one patient rated the experience as greater than "mild claustrophobia." 100% of patients answered either "none" or "mild" to the pain and shortness of breath questions. The NPFS (v.4) was then successfully used in four patients for laser laryngoscopy with biopsy of laryngeal papilloma (3/4) and hemorrhagic polyp (1/4). Post-procedure questionnaire identified no shortness of breath (4/4), no claustrophobia (4/4), no pain (4/4) and no significant changes in pulse oximetry during use. Conclusion: Extensive experience in performing diagnostic laryngoscopy with the NPFS directed design changes leading to successful use for transnasal flexible laser laryngoscopy with biopsy in a negative pressure microenvironment. Level of Evidence: Level 2b (Cohort Study).

Pre- and post-target cortical processes predict speech-in-noise performance.

Understanding speech in noise (SiN) is a complex task that recruits multiple cortical subsystems. There is a variance in individuals' ability to understand SiN that cannot be explained by simple hearing profiles, which suggests that central factors may underlie the variance in SiN ability. Here, we elucidated a few cortical functions involved during a SiN task and their contributions to individual variance using both within- and across-subject approaches. Through our within-subject analysis of source-localized electroencephalography, we investigated how acoustic signal-to-noise ratio (SNR) alters cortical evoked responses to a target word across the speech recognition areas, finding stronger responses in left supramarginal gyrus (SMG, BA40 the dorsal lexicon area) with quieter noise. Through an individual differences approach, we found that listeners show different neural sensitivity to the background noise and target speech, reflected in the amplitude ratio of earlier auditory-cortical responses to speech and noise, named as an internal SNR. Listeners with better internal SNR showed better SiN performance. Further, we found that the post-speech time SMG activity explains a further amount of variance in SiN performance that is not accounted for by internal SNR. This result demonstrates that at least two cortical processes contribute to SiN performance independently: pre-target time processing to attenuate neural representation of background noise and post-target time processing to extract information from speech sounds.

Auditory Working Memory Explains Variance in Speech Recognition in Older Listeners Under Adverse Listening Conditions.

INTRODUCTION: Older listeners have difficulty understanding speech in unfavorable listening conditions. To compensate for acoustic degradation, cognitive processing skills, such as working memory, need to be engaged. Despite prior findings on the association between working memory and speech recognition in various listening conditions, it is not yet clear whether the modality of stimuli presentation for working memory tasks should be auditory or visual. Given the modality-specific characteristics of working memory, we hypothesized that auditory working memory capacity could predict speech recognition performance in adverse listening conditions for older listeners and that the contribution of auditory working memory to speech recognition would depend on the task and listening condition. METHODS: Seventy-six older listeners and twenty younger listeners completed four kinds of auditory working memory tasks, including digit and speech span tasks, and sentence recognition tasks in four different listening conditions having multi-talker noise and time-compression. For older listeners, cognitive function was screened using the Mini-Mental Status Examination, and audibility was assured. RESULTS: Auditory working memory, as measured by listening span, significantly predicted speech recognition performance in adverse listening conditions for older listeners. A linear regression model showed speech recognition performance for older listeners could be explained by auditory working memory whilst controlling for the impact of age and hearing sensitivity. DISCUSSION: Measuring working memory in the auditory modality facilitated explaining the variance in speech recognition in adverse listening conditions for older listeners. The linguistic features and the complexity of the auditory stimuli may affect the association between working memory and speech recognition performance. CONCLUSION: We demonstrated the contribution of auditory working memory to speech recognition in unfavorable listening conditions in older populations. Taking the modality-specific characteristics of working memory into account may be a key to better understand the difficulty in speech recognition in daily listening conditions for older listeners.

Presentation and Outcomes of Elderly Patients Undergoing Head and Neck Surgeries: A National Perspective.

OBJECTIVES: To examine clinical profile and outcomes of elderly patients (65-90 years) undergoing head and neck surgeries in the United States. STUDY DESIGN: A retrospective cross-sectional analysis. SETTING: The Nationwide Readmissions Database, 2010 to 2015. SUBJECTS AND METHODS: Adult (≥18 years) patients who underwent head and neck surgeries. Analysis included χ2 test and logistic analysis. RESULTS: A total of 113,602 and 32,580 patients <65 and ≥65 years old, respectively, were included. Patients ≥65 years old were more likely to have multiple comorbidities (62.8% vs 32.6%, P < .001) and to present with head and neck cancer (19.8% vs 11.4%, P < .001). The most common comorbidity was diabetes (21.0%). The most common cancer types by site were mouth (29.12%), thyroid (28.08%), and nonmelanoma skin cancer (13.22%). The percentage of geriatric patients who underwent head and neck surgeries increased from 21.8% in 2010 to 25.0% in 2015 (P < .001). A total of 5450 (16.85%) patients developed postoperative complications, and the most common complications were pulmonary related (10.55%), bleeding (6.96%), acute renal failure (6.01%), and infection (3.97%). Blood transfusion was required in 3.53% of the patients. Readmission prevalence was 0.32%, and mortality risk was twice as likely (odds ratio, 2.05; 95% confidence interval, 1.77-2.38; P < .001). Independent risk factors of mortality were older age, multiple comorbidities, type of surgery, blood transfusion, and tracheostomy (P < .05, each). CONCLUSION: Elderly patients currently represent 25% of patients admitted for head and neck surgery. This population should be provided with a different level of care due to a higher risk of complications and mortality.

Adult Cochlear Implant Recipients' Perspectives on Experiences With Music in Everyday Life: A Multifaceted and Dynamic Phenomenon.

BACKGROUND: Cochlear implants (CIs), which have been designed primarily to support spoken communication of persons with severe to profound hearing loss, are highly effective in supporting speech perception in quiet listening conditions. CI users as a group achieve significantly poorer perception and appraisal of music, and speech perception is compromised when background music is present, though outcomes vary considerably across recipients. A number of factors have been identified that contribute to variable music listening experiences, but many questions remain, particularly regarding experiences in everyday life from the perspective of CI users. PURPOSE: The purpose of this study was twofold: The first aim was to explore the perspectives of adult CI recipients regarding two experiences with music in everyday life: purposeful music listening and background music that competes with spoken conversation. The second aim was to develop a framework of everyday music experiences based upon CI perspectives that could inform future rehabilitative practices and research initiatives. METHODS: Qualitative and patient-engaged research methodologies were used to emphasize the perspectives of the CI users. Participants included 40 experienced adult CI users ranging in age from 19 to 81 enrolled in 13 CI centers. Participants completed on-line semi-structured open-ended questionnaires regarding purposeful music listening and background music in conjunction with spoken communication. Responses were analyzed using an iterative inductive coding process consistent with grounded theory methodology. The interrelated themes that emerged from the data were then organized into a model synthesizing components from models on music response and self-management for persons with chronic health conditions. OUTCOMES: Data analyses informed the development of a Dynamic Problem Solving Model for Management of Music Listening Environments adapted from Hill-Briggs (2003) Problem Solving Model of Chronic Illness Self-Management. Key findings were: (1) Music listening is a dynamic, multifaceted experience; satisfactory listening depended upon optimal combinations of factors; (2) Music listening is effortful, but the extent of satisfaction is influenced by expectations and self-management of the situation; (3) CI users have limited access to resources for optimizing music experiences. Many CI users would consider rehabilitation, but level of commitment and priorities differ across CI users.

Intraductal Salivary Gland Infusion With Botulinum Toxin.

BACKGROUND: Administration of botulinum toxin through intraductal salivary infusion may decrease the risks of percutaneous needle injection and improve delivery to permeate the entire gland parenchyma. METHODS: The safety of intraductal salivary gland infusion was tested with prospective evaluation of two patients using interviews, clinical examination, and pressure measurement during infusion. Retrospective chart review of two subsequently treated patients assessed treatment of a parotid-cutaneous fistula and sialorrhea. RESULTS: No complications were identified in the safety study. Pressure changes during infusion supported the concept of botulinum neurotoxin delivery to permeate the gland. Patient-assessed success was subjectively reported as a reduction in the parotid-cutaneous output "by 95%" and the sialorrhea "by 90%" at 2-week follow-up. CONCLUSIONS: The intraductal route of botulinum toxin delivery to salivary glands was without complication and was effective in two patients treated therapeutically. Pressure measurements during infusion may be helpful to direct treatment. LEVEL OF EVIDENCE: 4.

Beyond Technology: The Interaction of Perceptual Accuracy and Experiential Factors in Pediatric Music Engagement.

BACKGROUND: Music engagement (the active making of music, e.g., music lessons and ensembles) is a common part of educational and community experiences. Music making typically involves listening to and production of rapidly changing combinations of pitch, timbre, and rhythm, which can be challenging for cochlear implant (CI) recipients, given that pitch and timbre are poorly conveyed through the CI. Pediatric CI users have variable patterns of music engagement, but some have achieved, sustained participation despite the degraded CI signal. What factors contribute to their persistence in these demanding listening situations? Our study examined a cohort of pediatric CI recipients from our center to better understand those perceptual and experiential factors most influential in relation to music engagement. METHOD: Regressions and correlations were run for measures of pitch and speech perception, hearing history, familial involvement in music, personal importance of music, and extent of music engagement (years in music lessons; general involvement in music). RESULTS: Pitch ranking accuracy was a significant predictor of sustained participation in music lessons (p = 0.0019), and sustained involvement in music (p = 0.0038), as well as performance on CNC words (p = -0.0060) and phonemes (p = -0.0174). Extent of familial involvement in music at the time of testing was significantly predictive of the user's musical engagement (p = 0.0007). Personal importance of music was not predicted by or significantly correlated with, any of the variables investigated. CONCLUSION: Better pitch perception was associated with sustained involvement in music lessons as well as better speech perception. However, familial involvement in music was of greater impact for sustained music engagement. Judicious choice of musical instrument also influenced persistence. The positive impact of familial involvement indicates that perceptual limitations associated with CI processing do not present insurmountable barriers to music engagement. Because music engagement provides normalizing social involvement and challenging auditory practice, the impact of parental involvement has implications for counseling parents of CI users.

Electric and acoustic harmonic integration predicts speech-in-noise performance in hybrid cochlear implant users.

BACKGROUND: Pitch perception of complex tones relies on place or temporal fine structure-based mechanisms from resolved harmonics and the temporal envelope of unresolved harmonics. Combining this information is essential for speech-in-noise performance, as it allows segregation of a target speaker from background noise. In hybrid cochlear implant (H-CI) users, low frequency acoustic hearing should provide pitch from resolved harmonics while high frequency electric hearing should provide temporal envelope pitch from unresolved harmonics. How the acoustic and electric auditory inputs interact for H-CI users is largely unknown. Harmonicity and inharmonicity are emergent features of sound in which overtones are concordant or discordant with the fundamental frequency. We hypothesized that some H-CI users would be able to integrate acoustic and electric information for complex tone pitch perception, and that this ability would be correlated with speech-in-noise performance. In this study, we used perception of inharmonicity to demonstrate this integration. METHODS: Fifteen H-CI users with only acoustic hearing below 500 Hz, only electric hearing above 2 kHz, and more than 6 months CI experience, along with eighteen normal hearing (NH) controls, were presented with harmonic and inharmonic sounds. The stimulus was created with a low frequency component, corresponding with the H-CI user's acoustic hearing (fundamental frequency between 125 and 174 Hz), and a high frequency component, corresponding with electric hearing. Subjects were asked to identify the more inharmonic sound, which requires the perceptual integration of the low and high components. Speech-in-noise performance was tested in both groups using the California Consonant Test (CCT), and perception of Consonant-Nucleus-Consonant (CNC) words in quiet and AzBio sentences in noise were tested for the H-CI users. RESULTS: Eight of the H-CI subjects (53%), and all of the NH subjects, scored significantly above chance level for at least one subset of the inharmonicity detection task. Inharmonicity detection ability, but not age or pure tone average, predicted speech scores in a linear model. These results were significantly correlated with speech scores in both quiet and noise for H-CI users, but not with speech in noise performance for NH listeners. Musical experience predicted inharmonicity detection ability, but did not predict speech performance. CONCLUSIONS: We demonstrate integration of acoustic and electric information in H-CI users for complex pitch sensation. The correlation with speech scores in H-CI users might be associated with the ability to segregate a target speaker from background noise using the speaker's fundamental frequency.

Utility of preoperative computed tomography and magnetic resonance imaging in adult and pediatric cochlear implant candidates.

OBJECTIVES/HYPOTHESIS: Determine the utility of preoperative imaging in adult and pediatric cochlear implant candidates. STUDY DESIGN: Retrospective chart review. METHODS: Medical records of 101 consecutive adult and 20 consecutive pediatric patients who underwent 137 cochlear implantation (CI) procedures at a single institution were reviewed. RESULTS: Computed tomography (CT) was obtained preoperatively in 110 (90.9%) patients, preoperative magnetic resonance imaging (MRI) was obtained in 102 (84.3%) patients, and both were obtained in 94 (77.7%) patients. MRI revealed one acoustic neuroma and two meningiomas, which affected surgical planning for three (2.2%) procedures. MRI identified enlarged vestibular aqueduct (EVA) in 2.0% of adult patients. CT demonstrated middle ear disease in four (3.3%) patients. CT was useful in indicating round window and cochlear patency in three (2.2%) patients with cochlear otosclerosis. Twenty pediatric patients underwent 27 CI procedures. Preoperative CT in the pediatric cohort demonstrated five (25%) dysplastic cochleae, three (15%) dysplastic vestibules and/or semicircular canals, and three (15%) EVAs. In one patient, CT demonstrated a duplicated right internal auditory canal (IAC) and hypoplastic left IAC; MRI confirmed hypoplastic cochlear nerves. CONCLUSIONS: Preoperative MRI can demonstrate retrocochlear pathology, cochlear patency, and EVA in adults being evaluated for cochlear implantation. CT may provide additional information in patients with chronic otitis media or otosclerosis. However, in postlingually deafened adults without conductive or asymmetrical hearing loss, imaging is unlikely to affect surgical decision making. Both CT and MRI can identify anomalies in pediatric patients. MRI does not offer substantial benefit over CT for routine evaluation of pediatric inner ear and temporal bone anatomy. LEVEL OF EVIDENCE: 4 Laryngoscope, 126:1440-1445, 2016.