Structural connectivity changes in unilateral hearing loss.

Network connectivity, as mapped by the whole brain connectome, plays a crucial role in regulating auditory function. Auditory deprivation such as unilateral hearing loss might alter structural network connectivity; however, these potential alterations are poorly understood. Thirty-seven acoustic neuroma patients with unilateral hearing loss (19 left-sided and 18 right-sided) and 19 healthy controls underwent diffusion-weighted and T1-weighted imaging to assess edge strength, node strength, and global efficiency of the structural connectome. Edge strength was estimated by pair-wise normalized streamline density from tractography and connectomics. Node strength and global efficiency were calculated through graph theory analysis of the connectome. Pure-tone audiometry and word recognition scores were used to correlate the degree and duration of unilateral hearing loss with node strength and global efficiency. We demonstrate significantly stronger edge strength and node strength through the visual network, weaker edge strength and node strength in the somatomotor network, and stronger global efficiency in the unilateral hearing loss patients. No discernible correlations were observed between the degree and duration of unilateral hearing loss and the measures of node strength or global efficiency. These findings contribute to our understanding of the role of structural connectivity in hearing by facilitating visual network upregulation and somatomotor network downregulation after unilateral hearing loss.

[Recognition of unilateral auditory neuropathy in children].

Objective: This study aimed to compare the audiological characteristics between children with unilateral auditory neuropathy (UAN) and single-sided deafness (SSD) to establish a valid basis for the differential diagnosis of children with UAN. Methods: A retrospective analysis was conducted on audiological and imaging evaluations of children with UAN and SSD who were treated at Beijing Children's Hospital of Capital Medical University between May 2015 and June 2023. There were 17 children with UAN, comprising 10 males and 7 females, with an average age of 4.7 years. Additionally, there were 43 children with SSD, consisting of 27 males and 16 females, with an average age of 6.5 years. Audiological assessments included Auditory brainstem response (ABR), Steady-state auditory evoked potential (ASSR), Behavioural audiometry, Cochlear microphonic potential (CM), Distortino-product otoacoustic emission (DPOAE), and acoustic immittance test. The results of the audiological assessment and imaging phenotypic between the two groups of children were compared and analyzed by applying SPSS 27.0 statistical software. Results: (1) The UAN group (77.8%) had a significantly higher rate of ABR wave IIIL than the SSD group (20.9%) (P<0.01). The PA thresholds at 500 Hz and 1 000 Hz of children with SSD were higher than those of children with UAN, while the ASSR thresholds at 500 Hz, 1000 Hz, 2 000 Hz, and 4 000 Hz of children with SSD were significantly higher than those of children with UAN (P<0.05). (2) The degree of hearing loss in both UAN and SSD children was predominantly complete hearing loss. The percentage of complete hearing loss was significantly higher (χ²=4.353, P=0.037) in the SSD group (93.0%, 40/43) than in the UAN group (63.6%, 7/11). However, the percentage of profound hearing loss was significantly higher in the UAN group (27.3%, 3/11) than in the SSD group (2.3%, 1/43) (Fisher's exact test, P=0.023). In terms of hearing curve configuration, the percentage of flat type was significantly higher in the SSD group (76.7%, 33/43) than in the UAN group (36.4%, 4/11). The proportion of the UAN group (27.3%, 3/11) was significantly higher than that in the SSD group (2.3%, 1/43) in ascending type (P<0.05). There were no statistically significant differences in the hearing curves of the declining type and other types between the two groups (P>0.05). (3) The proportion of imaging assessment without abnormality was significantly more common in the UAN group (81.8%) than in the SSD group (37.1%) (χ²=6.695, P=0.015). Conclusions: Compared to children with SSD, the occurrence of wave IIIL on the ABR test was significantly more common in children with UAN. The percentage of ascending hearing curves was significantly higher in children with UAN than in children with SSD. ASSR thresholds were significantly lower in children with UAN. The normal imaging phenotype was significantly more common in children with UAN than in children with SSD.

Clinical experience of an adhesive bone conduction hearing system in children with congenital single-sided deafness.

OBJECTIVES: This study aimed to investigate the effects of an adhesive bone conduction device (aBCD) in children with congenital single-sided deafness (SSD). Specifically, we examined whether the aBCD elicits improvement in the speech perception ability of children with congenital SSD and whether using this device would adversely affect the horizontal localisation abilities of these children. METHODS: Thirteen school-aged children with SSD and seven children with Normal Hearing (NH) were included in this study. Speech perception in noise was measured using the Mandarin Speech Test Materials and sound localisation performance was evaluated using broadband noise stimuli (0.5-20 kHz), randomly played from seven loudspeakers at different stimulus levels (65-, 70-, and 75-dB SPL). RESULTS: All children with SSD showed inferior speech perception and sound localisation performance compared with children with NH. The aBCD use remarkably improved the speech perception abilities of these children under quiet and noise conditions; however, their sound localisation abilities neither improved nor deteriorated. CONCLUSION: This study reveals the effectiveness and safety of a non-surgical aBCD in paediatric patients with SSD. Our results provide a theoretical basis for early hearing intervention with an aBCD in children with congenital SSD who are temporarily unable to undergo ear surgery. LEVEL OF EVIDENCE: Level 3.

Factors Predictive of Binaural Hearing Restoration by Cochlear Implant in Single-Sided Deafness.

INTRODUCTION: Cochlear implants (CIs) can restore binaural hearing in cases of single-sided deafness (SSD). However, studies with a high level of evidence in support of this phenomenon are lacking. The aim of this study is to analyze the effectiveness of CIs using several spatialized speech-in-noise tests and to identify potential predictors of successful surgery. METHODS: Ten cases underwent standard CI surgery (MEDEL-Flex24). The speech-in-noise test was used in three different spatial configurations. The noise was presented from the front (N0), toward the CI (NCI), and toward the ear (Near), while the speech was always from the front (S0). For each test, the speech-to-noise ratio at 50% intelligibility (SNR50) was evaluated. Seven different effects were assessed (summation, head shadow [HS], speech released of masking [SRM], and squelch for the CI and for the ear). RESULTS: A significant summation effect of 1.5 dB was observed. Contralateral PTA was positively correlated with S0N0-B and S0NCI-B (CIon and unplugged ear). S0N0-B results were positively correlated with S0N0-CIoff (p < 0.0001) and with S0Near-CIoff results (p = 0.004). A significant positive correlation was found between delay post-activation and HS gain for the CI (p = 0.005). Finally, the HS was negatively correlated with the squelch effect for the ear. CONCLUSION: CI benefits patients with SSD in noise and can improve the threshold for detecting low-level noise. Contralateral PTA could predict good postoperative results. Simple tests performed preoperatively can predict the likelihood of surgical success in reversing SSD.

Hearing Status and Aural Rehabilitative Profile of 878 Patients With Sporadic Vestibular Schwannoma.

OBJECTIVES/HYPOTHESIS: To examine the hearing status and aural rehabilitative profile in a national cohort of patients with sporadic vestibular schwannoma (VS). STUDY DESIGN: Cross-sectional survey METHODS: A cross-sectional survey of Acoustic Neuroma Association members diagnosed with sporadic VS was performed from February 2017 through January 2019. Self-reported results were used to determine the aural rehabilitative profile of respondents. RESULTS: Among survey respondents, 62.2% (546/878) were not using any hearing-assistive device at time of survey. For the 37.8% (332/878) that were utilizing hearing-assistive devices, 32.8% (109/332) reported using a behind-the-ear hearing aid, 23.8% (79/332) used a contralateral routing of signal (CROS) hearing aid, and 21.7% (72/332) used a bone conduction device. Notably, 41.9% (278/663) of patients who previously underwent tumor treatment reported utilizing a hearing rehabilitation device at some point during VS management compared to 27.0% (58/215) of those undergoing observation with serial imaging (P < .001). Of 275 patients with functional hearing in the ipsilateral ear, 26.5% (73/275) reported having used at least one type of hearing device; 24.0% (66/275) reported use of a conventional hearing aid, 0.7% (2/275) a CROS aid, and 0.4% (1/275) a bone conduction device. Among respondents reporting ipsilateral nonfunctional hearing, 44.9% (258/575) reported having used at least one type of hearing device; 13.0% (75/575) a CROS aid, and 12.3% (71/575) a bone conduction device. CONCLUSIONS: Even among a cohort with presumably elevated literacy surrounding hearing rehabilitation options, few patients with a history of unilateral vestibular schwannoma ultimately use hearing assistive devices long-term, suggesting that most patients sufficiently adjust to unilateral hearing loss or are unsatisfied with the benefits achieved with current device options. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:1378-1381, 2021.

Estimating Real-World Performance of Percutaneously Coupled Bone-Conduction Device Users With Severe-to-Profound Unilateral Hearing Loss.

Purpose The bone-conduction device attached to a percutaneous screw (BCD) is an important treatment option for individuals with severe-to-profound unilateral hearing loss (UHL). Clinicians may use subjective questionnaires and speech-in-noise measures to evaluate BCD use in this patient population; however, the translation of these metrics to real-world aided performance is unclear. The purpose of this study was twofold: first, to measure speech-in-noise performance in BCD users with severe-to-profound UHL in a simulated real-world environment, relative to individuals with normal hearing bilaterally; second, to determine if BCD users' subjective reports of aided performance relate to simulated real-world performance. Method A between-subjects design with two groups was conducted with 14 adults with severe-to-profound UHL (BCD group) and 10 age-matched participants with normal hearing bilaterally (control group). Speech-in-noise tests were administered in an eight-speaker R-Space simulating a real-world environment. To further explore speech-in-noise evaluation methods for this population, testing was also completed in a clinically common two-speaker array. The effects of various microphone settings on performance were explored for BCD users. Subjective performance was measured with the Abbreviated Profile of Hearing Aid Benefit (APHAB; Cox & Alexander, 1995) and the Speech, Spatial and Qualities of Hearing Scale (Gatehouse & Noble, 2004). Statistical analyses to explore relationships between variables included repeated-measures analysis of variance, regression analyses, independent-samples t tests, nonparametric Mann-Whitney tests, and correlations. Results In the simulated real-world environment, BCD group participants struggled with speech-in-noise understanding compared to control group participants. BCD benefit was observed for all microphone settings when speech stimuli were presented to the side with the BCD. When adaptive directional or fixed directional microphone settings were used, a relationship was noted between simulated real-world speech-in-noise performance for speech stimuli presented to the side with the BCD and subjective reports on the Background Noise subscale of the APHAB. Conclusions The Background Noise subscale of the APHAB may help estimate real-world speech-in-noise performance for BCD users with severe-to-profound UHL for signals of interest presented to the implanted side, specifically when adaptive or fixed directional microphone settings are used. This subscale may provide an efficient and accessible alternative to assessing real-world speech-in-noise performance in lieu of less clinically available measurement tools, such as an R-Space.

Association Between Hearing Loss and Postural Instability in Older Korean Adults.

Importance: Hearing loss is one of the most frequently occurring sensory disabilities worldwide. The association between hearing loss and postural instability in an older population remains to be studied. Objective: To determine whether the odds of postural instability increase with the degree of hearing loss and to suggest criteria for hearing rehabilitation for postural instability. Design, Setting, and Participants: This cross-sectional population-based study of 3864 participants 40 years and older with hearing loss used data from 2010 through 2012 in the fifth edition of the Korea National Health and Nutrition Examination Survey, a nationwide survey of South Korea. Pure tone audiometry was performed on both the left and right sides and each hearing grade of each side was classified into 1 of 3 subcategories: normal hearing, mild hearing loss, or moderate hearing loss (moderate hearing loss or worse). Postural instability was defined as the failure to remain standing on a foam pad surface with feet 10 cm apart with arms folded and hands cupping the elbows and eyes closed. A binomial logistic regression model was used to assess the association between hearing loss and postural instability. Data were analyzed from August 18, 2019, to September 2, 2019. Exposures: Age-related hearing loss defined as a threshold of 26 dB or more. Main Outcomes and Measures: The degree of hearing loss and postural instability. Results: Of the 3864 participants included in the study, the mean (SD) age was 57.8 (11.3) years and 2135 (55.2%) were women. Female sex was associated with higher odds of postural instability compared with male sex (odds ratio [OR], 1.65; 95% CI, 1.12-2.42, adjusted for age and hearing status), and the odds of postural instability increased with every 1 year increase in age (OR, 1.13; 95% CI, 1.10-1.16, adjusted for sex and hearing status). Unilateral or bilateral mild hearing loss was not associated with an increase in the odds of postural instability, but moderate hearing loss present on at least 1 side was associated with an increase in the odds of postural instability: unilateral moderate hearing loss group (OR, 2.71; 95% CI, 1.12-6.10, adjusted for age and sex), one mild and the other moderate hearing loss group (OR, 2.18; 95% CI, 1.16-4.09, adjusted for age and sex), and bilateral moderate hearing loss group (OR, 2.34; 95% CI, 1.27-4.33, adjusted for age and sex). Conclusions and Relevance: Aging, female sex, and having hearing loss were associated with postural instability in this analysis. Moderate or worse hearing loss present on at least 1 side was associated with increased odds of postural instability. Future research in this area is warranted to identify more precise interrelationships and preventive measures.

Subjective Benefits of Bimodal Listening in Cochlear Implant Recipients with Asymmetric Hearing Loss.

OBJECTIVE: To investigate the influence of cochlear implant (CI) use on subjective benefits in quality of life in cases of asymmetric hearing loss (AHL). STUDY DESIGN: Prospective clinical trial. SETTING: Tertiary academic center. SUBJECTS AND METHODS: Subjects included CI recipients with AHL (n = 20), defined as moderate-to-profound hearing loss in the affected ear and mild-to-moderate hearing loss in the contralateral ear. Quality of life was assessed with the Speech, Spatial, and Qualities of Hearing Scale (SSQ) pragmatic subscales, which assess binaural benefits. Subjective benefit on the pragmatic subscales was compared to word recognition in quiet and spatial hearing abilities (ie, masked sentence recognition and localization). RESULTS: Subjects demonstrated an early, significant improvement (P < .01) in abilities with the CI as compared to preoperative abilities on the SSQ pragmatic subscales by the 1-month interval. Perceived abilities were either maintained or continued to improve over the study period. There were no significant correlations between results on the Speech in Quiet subscale and word recognition in quiet, the Speech in Speech Contexts subscale and masked sentence recognition, or the Localization subscale and sound field localization. CONCLUSIONS: CI recipients with AHL report a significant improvement in quality of life as measured by the SSQ pragmatic subscales over preoperative abilities. Reported improvements are observed as early as 1 month postactivation, which likely reflect the binaural benefits of listening with bimodal stimulation (CI and contralateral hearing aid). The SSQ pragmatic subscales may provide a more in-depth insight into CI recipient experience as compared to behavioral sound field measures alone.

Minimal invasive pocket technique for magnet bone implant hearing aid without fixation.

INTRODUCTION: The BAHA (bone-anchored hearing aid) Attract is a magnetic transcutaneous bone conduction device anchored into the temporal bone. The standard surgical technique for BAHA Attract is a multi-tools time-consuming process, which requires a large cutaneous incision. The objective of this study is to describe and test the feasibility of a minimally invasive pocket (MIP) technique for Magnet Bone Implant Hearing Aid (MBIHA) with a modified magnet of BAHA Attract without fixation and without any tissue reduction. We use a 3-cm vertical skin incision and a subperiosteal pocket. METHOD: A study of 10 patients with conductive or mixed hearing loss who benefited from a MBIHA using the MIP technique is presented. The pure tone average (PTA) (dB) for air-conduction thresholds and the speech recognition threshold (SRT) (dB) in speech audiometry in quiet are calculated. The Entific Medical Systems (EMS) questionnaire and the postoperative clinical outcomes are realized. RESULTS: We found a significant improvement of 33.8 dB on average for the PTA and 44.8 dB for the SRT with MBIHA at 3 months, compared with unaided situation. No implant was removed or displaced after 2 years of follow-up. The skin condition remains intact in all the cases. CONCLUSION: The minimally subperiosteal pocket surgical technique MIP without fixation and with tissue preservation for the MBIHA is safe, rapid and effective for patients with conductive or mixed hearing loss. It opens new perspectives of development and modify conventional concept in magnetic coupling of bone-conducted device.

Low-Frequency Hearing Preservation With Long Electrode Arrays: Inclusion of Unaided Hearing Threshold Assessment in the Postoperative Test Battery.

Purpose The goal of this work was to evaluate the low-frequency hearing preservation of long electrode array cochlear implant (CI) recipients. Method Twenty-five participants presented with an unaided hearing threshold of ≤ 80 dB HL at 125 Hz pre-operatively in the ear to be implanted. Participants were implanted with a long (31.5-mm) electrode array. The unaided hearing threshold at 125 Hz was compared between the preoperative and postoperative intervals (i.e., initial CI activation, and 1, 3, 6, 9, and 12 months after activation). Results Eight participants maintained an unaided hearing threshold of ≤ 80 dB HL at 125 Hz postoperatively. The majority (n = 5) demonstrated aidable low-frequency hearing at initial activation, whereas 3 other participants experienced an improvement in unaided low-frequency hearing thresholds at subsequent intervals. Conclusions CI recipients can retain residual hearing sensitivity with fully inserted long electrode arrays, and low-frequency hearing thresholds may improve during the postoperative period. Therefore, unaided hearing thresholds obtained within the initial weeks after surgery may not reflect later hearing sensitivity. Routine measurement of postoperative unaided hearing thresholds-even for patients who did not demonstrate aidable hearing thresholds initially after cochlear implantation-will identify CI recipients who may benefit from electric-acoustic stimulation. Supplemental Material https://doi.org/10.23641/asha.11356637.

Imaging findings in pediatric single-sided deafness and asymmetric hearing loss.

OBJECTIVE: To examine the imaging findings on computer tomography (CT) and magnetic resonance imaging (MRI) in pediatric single-sided deafness (SSD) and asymmetric hearing loss (ASH). METHODS: The medical records of 189 pediatric patients with SSD and ASH were retrospectively reviewed, and imaging findings were compared. SSD was defined as unilateral profound hearing loss and contralateral normal hearing ear. In the ASH group, ASHw was defined as the worse hearing ear with profound hearing loss, while ASHb was defined as the better hearing ear with mild-moderate hearing loss. RESULTS: There were 170 patients with SSD and 19 patients with ASH. In the SSD group, 83 patients (48.8%) had imaging findings associated with hearing loss. In the ASH group, such imaging findings were found in six (31.6%) of the ASHw and in five (26.3%) of the ASHb ears. The most common finding in the SSD group was cochlear nerve deficiency (50.6%), followed by cochlear dysplasia (39.8%) and enlarged vestibular aqueduct (26.5%). In the ASH groups, cochlear dysplasia was seen in three (50%) of ASHw ears and in two (40%) of the ASHb ears, and enlarged vestibular aqueduct was seen in three (50%) of ASHw ears and in two (40%) of the ASHb ears. CONCLUSION: Imaging studies identified the etiology in half of the cases of SSD and in one-third of ASH patients. Our findings strongly support the use of imaging studies in the evaluation of pediatric SSD and ASH. LEVEL OF EVIDENCE: 4 Laryngoscope, 130:1007-1010, 2020.

An fMRI-study on single-sided deafness: Spectral-temporal properties and side of stimulation modulates hemispheric dominance.

OBJECTIVE: Our main aim was to investigate the blood oxygenation level dependent (BOLD) response to monaural and binaural speech- and non-speech stimuli as measured with fMRI in subjects with single-sided deafness and in normal hearing controls. We hypothesised that the response to monaural stimulation in both normal hearing subjects and persons with single-sided deafness would vary with the complexity and nature of the stimuli and the side of stimulation. DESIGN: Patients with left- and right single-sided deafness and controls with normal hearing receiving either binaural or monaural stimuli were tested using speech and non-speech auditory stimuli in an event-related fMRI experiment. STUDY SAMPLE: Twenty-two patients with single-sided deafness after treatment for vestibular schwannoma and 50 normal hearing controls. RESULTS: Normal hearing persons receiving right side monaural stimuli activate bilateral temporal regions. Activation following left side monaural stimulation is more right lateralized. Persons with single-sided deafness respond similarly to controls to monaural stimulation. Persons with right side single-sided deafness show activation of frontal cortical regions not seen in persons with left side single-sided deafness following speech stimuli. This is possibly related to increased effort and more frequently reported problems with communication. Right side single-sided deafness is related to increased activation of areas usually related to processing of degraded input, including the thalamus. CONCLUSION: Hemispheric dominance following monaural auditory stimulation is modulated by the spectral-temporal properties of the stimuli and by which ear is stimulated. Differences between patients with right- and left side deafness suggests that right side deafness is related to increased activation of areas involved in processing of degraded input.

Pigmented Villonodular Synovitis Presenting as Unilateral Hearing Loss: Review of the Literature and Case Report.

BACKGROUND/AIMS: To review the existing literature on pigmented villonodular synovitis (PVNS) of the temporomandibular joint (TMJ) and report a rare case of PVNS of the TMJ presenting with unilateral hearing loss. METHODS: Review of the existing literature and a description of personal experience with PVNS of the TMJ presenting with unilateral hearing loss. RESULTS: Review of the existing literature revealed 76 reported cases of PVNS of the TMJ. The most common presenting symptom was of a slowly enlarging mass or swelling of the preauricular area, with dysfunctional TMJ also frequently reported. All patients underwent surgical excision with some pursuing radiation as adjuvant therapy. Presented Patient: A 46-year-old man presented with several months of unilateral subjective hearing loss and aural fullness. Imaging revealed a mass centered along the superior TMJ with expansion through the squamous temporal bone and extra-axial intracranial extension into the middle cranial fossa. Imaging characteristics and fine-needle aspiration biopsy were consistent with PVNS. INTERVENTION: The patient underwent near-total excision of the mass via frontotemporal craniectomy and lateral temporal bone resection. FOLLOW-UP: At the 16-month follow-up there was no evidence of disease recurrence. CONCLUSION: PVNS of the TMJ represents a rare entity that can present with a variety of symptoms including unilateral hearing loss.

A Prospective Randomized Crossover Study in Single Sided Deafness on the New Non-Invasive Adhesive Bone Conduction Hearing System.

BACKGROUND: Recently, an adhesive bone conduction hearing system has been developed for conductive hearing loss or single-sided deafness (SSD). In SSD cases, this device may be a good solution for patients who are unsuitable for, or who do not wish to undergo, bone conduction implant or cochlear implant surgery. The study aimed to investigate the hearing outcomes with the adhesive hearing system in SSD. PURPOSE OF THE STUDY: The study aimed to investigate the hearing outcomes with the adhesive hearing system in SSD. METHODS: A randomized crossover study was conducted in 17 SSD participants, using CROS (contralateral routing of signals) hearing aid as a control. Following outcome measurements were administered after a two-week trial: 1) Speech, Spatial and Qualities scale, Audio Processor Satisfaction Questionnaire, and a custom-made questionnaire about the use of the system, 2) sound localization, 3) speech perception in noise. RESULTS: 70% of the SSD subjects reported that the adhesive hearing system was partially useful or better. Using the APSQ, the adhesive test device was evaluated equally as the control device. Sound localization improved with the adhesive test device and deteriorated with the control device. There was no improvement in speech perception in noise measured with the adhesive test device. Speech perception in noise (SSSDNNH) with the control device improved significantly. CONCLUSION: To the best of our knowledge, this is the first study to report on the outcomes of the new adhesive system. Users' satisfaction of the adhesive hearing system was found to be comparable to the control device. Since the hearing outcomes vary highly between patients, trials with applicable hearing systems are recommended in SSD patients.

Altered functional networks in long-term unilateral hearing loss: A connectome analysis.

Introduction: In neuroimaging studies, long-term unilateral hearing loss (UHL) is associated with functional changes in specific brain regions and connections; however, little is known regarding alterations in the topological organization of whole-brain functional networks and whether these alterations are related to hearing behavior in UHL patients. Methods: We acquired resting-state fMRI data from 21 patients with UHL caused by acoustic neuromas and 21 matched healthy controls. Whole-brain functional networks were constructed by measuring interregional temporal correlations of 278 brain regions. Alterations in interregional functional connectivity and topological properties (e.g., small-world, efficiency, and nodal centrality) were identified using graph-theory analysis. The subjects also completed a battery of hearing behavior measures. Results: Both UHL patients and controls exhibited efficient small-world properties in their functional networks. Compared with controls, UHL patients showed increased and decreased nodal centrality in distributed brain regions. Furthermore, the brain regions with significantly increased and decreased functional connections associated with UHL were components of the following important networks: (1) visual network; (2) higher-order functional networks, including the default-mode and attention networks; and (3) subcortical network and cerebellum. Intriguingly, the changes in intranetwork connections in UHL were significantly correlated with disease duration and hearing level. Conclusions: This study revealed connectome-level alterations involved in multiple large-scale networks related to sensory and higher-level cognitive functions in long-term UHL patients. These reorganizations of the brain in UHL patients may depend on the stage of deafness and hearing level. Together, our findings provided empirical evidence for understanding the neuroplastic mechanisms underlying hearing impairment, establishing potential biomarkers for monitoring the progression and further treatment effects for UHL patients.

Hybrid cochlear implantation: quality of life, quality of hearing, and working performance compared to patients with conventional unilateral or bilateral cochlear implantation.

The objective of the present study is to evaluate the effect of hybrid cochlear implantation (hCI) on quality of life (QoL), quality of hearing (QoH), and working performance in adult patients, and to compare the long-term results of patients with hCI to those of patients with conventional unilateral cochlear implantation (CI), bilateral CI, and single-sided deafness (SSD) with CI. Sound localization accuracy and speech-in-noise test were also compared between these groups. Eight patients with high-frequency sensorineural hearing loss of unknown etiology were selected in the study. Patients with hCI had better long-term speech perception in noise than uni- or bilateral CI patients, but the difference was not statistically significant. The sound localization accuracy was equal in the hCI, bilateral CI, and SSD patients. QoH was statistically significantly better in bilateral CI patients than in the others. In hCI patients, residual hearing was preserved in all patients after the surgery. During the 3.6-year follow-up, the mean hearing threshold at 125-500 Hz decreased on average by 15 dB HL in the implanted ear. QoL and working performance improved significantly in all CI patients. Hearing outcomes with hCI are comparable to the results of bilateral CI or CI with SSD, but hearing in noise and sound localization are statistically significantly better than with unilateral CI. Interestingly, the impact of CI on QoL, QoH, and working performance was similar in all groups.

Speech and Language Consequences of Unilateral Hearing Loss: A Systematic Review.

Objective Unilateral hearing loss has been shown to have negative consequences for speech and language development in children. The objective of this study was to systematically review the current literature to quantify the impact of unilateral hearing loss on children, with the use of objective measures of speech and language. Data Sources PubMed, EMBASE, Medline, CINAHL, and Cochrane Library were searched from inception to March 2015. Manual searches of references were also completed. Review Methods All studies that described speech and language outcomes for children with unilateral hearing loss were included. Outcome measures included results from any test of speech and language that evaluated or had age-standardized norms. Due to heterogeneity of the data, quantitative analysis could not be completed. Qualitative analysis was performed on the included studies. Two independent evaluators reviewed each abstract and article. Results A total of 429 studies were identified; 13 met inclusion criteria and were reviewed. Overall, 7 studies showed poorer scores on various speech and language tests, with effects more pronounced for children with severe to profound hearing loss. Four studies did not demonstrate any difference in testing results between patients with unilateral hearing loss and those with normal hearing. Two studies that evaluated effects on speech and language longitudinally showed initial speech problems, with improvement in scores over time. Conclusions There are inconsistent data regarding effects of unilateral hearing loss on speech and language outcomes for children. The majority of recent studies suggest poorer speech and language testing results, especially for patients with severe to profound unilateral hearing loss.

Auditory Outcomes with Hearing Rehabilitation in Children with Unilateral Hearing Loss: A Systematic Review.

Objective Options for management of unilateral hearing loss (UHL) in children include conventional hearing aids, bone-conduction hearing devices, contralateral routing of signal (CROS) aids, and frequency-modulating (FM) systems. The objective of this study was to systematically review the current literature to characterize auditory outcomes of hearing rehabilitation options in UHL. Data Sources PubMed, EMBASE, Medline, CINAHL, and Cochrane Library were searched from inception to January 2016. Manual searches of bibliographies were also performed. Review Methods Studies analyzing auditory outcomes of hearing amplification in children with UHL were included. Outcome measures included functional and objective auditory results. Two independent reviewers evaluated each abstract and article. Results Of the 249 articles identified, 12 met inclusion criteria. Seven articles solely focused on outcomes with bone-conduction hearing devices. Outcomes favored improved pure-tone averages, speech recognition thresholds, and sound localization in implanted patients. Five studies focused on FM systems, conventional hearing aids, or CROS hearing aids. Limited data are available but suggest a trend toward improvement in speech perception with hearing aids. FM systems were shown to have the most benefit for speech recognition in noise. Studies evaluating CROS hearing aids demonstrated variable outcomes. Conclusions Data evaluating functional and objective auditory measures following hearing amplification in children with UHL are limited. Most studies do suggest improvement in speech perception, speech recognition in noise, and sound localization with a hearing rehabilitation device.

Perception of Iterated Rippled Noise Periodicity in Cochlear Implant Users.

Pitch perception is more challenging for individuals with cochlear implants (CIs) than normal-hearing subjects because the signal processing by CIs is restricted. Processing and perceiving the periodicity of signals may contribute to pitch perception. Whether individuals with CIs can discern pitch within an iterated rippled noise (IRN) signal is still unclear. In a prospective controlled psychoacoustic study with 34 CI users and 15 normal-hearing control subjects, the difference limen between IRN signals with different numbers of iterations was measured. In 7 CI users and 15 normal-hearing control listeners with single-sided deafness, pitch matching between IRN and harmonic complex tones was measured. The pitch onset response (POR) following signal changes from white noise to IRN was measured electrophysiologically. The CI users could discriminate different numbers of iteration in IRN signals, but worse than normal-hearing listeners. A POR was measured for both normal-hearing subjects and CI users increasing with the pitch salience of the IRN. This indicates that the POR could serve as an objective measure to monitor progress during audioverbal therapy after CI surgery.

[Advances in effect of unilateral auditory deprivation on sound localization].

In patients with single-sided deafness (SSD), the interaural time difference and the interaural level difference signals are insufficient or missing, which result in the lack of sound localization ability and the decrease of speech comprehension in the noise environments. SSD can also cause the morphological and functional changes of the central auditory system, resulting in auditory deprivation. In early stage of the development, the auditory center is more susceptible to ambient environment and auditory inputs. It is a critical period of auditory function and morphological refinement. It is also sensitive period of central adaptability after auditory deprivation. SSD in the sensitive period of development can cause significant laterality activities of bilateral sound localization pathway. Unilateral auditory deprivation can distort tonotopic maps, disrupt the binaural integration, reorganize the neural network and change the synaptic transmission in the primary auditory cortex or sub cortex. In order to compensate for the deficiency of the interaural time difference and interaural level difference cues, the auditory pathway is used to improve the ability of sound source localization by using the spectral-shape cues remaining unchanged. In order to improve the effectiveness of the functional areas of the cortex, auditory center is also reorganized by cross-modal. However, central compensation after SSD is a double-edged sword. If SSD onset in the sensitive period, the laterality of auditory pathway will be continued and difficult to reverse by even long term bilateral hearing in the post-sensitive period. Therefore, in order to improve the understanding of the characteristics of unilateral auditory deprivation, this paper reviewed the evidence for adaptive changes in spatial hearing following a developmental hearing loss in one ear.