Influence of Tinnitus on Auditory Spectral and Temporal Resolution and Speech Perception in Tinnitus Patients.

Although cochlear damage is believed to trigger the perception of tinnitus in the central auditory system, its pathophysiological mechanism is still unclear. We aimed to investigate the pathophysiology of tinnitus using psychoacoustic assessments of auditory spectral and temporal resolution and speech perception in noise. Human subjects with tinnitus and symmetric hearing thresholds were divided into three groups: nine unilateral tinnitus subjects with normal hearing thresholds (Group 1), 12 unilateral tinnitus subjects with hearing loss (HL; Group 2), and nine bilateral tinnitus subjects with HL. Fifteen normal-hearing subjects without tinnitus were also tested as a control group. Four different tests were administered: (1) the spectral-ripple discrimination (SRD) test, (2) the temporal modulation detection (TMD) test, (3) the Schroeder-phase discrimination (SPD) test, and (4) the speech recognition threshold (SRT) in noise test. There were no significant differences in SRD, TMD, and SPD between the tinnitus-affected ears (TEs) and non-tinnitus ears (NTEs) in Groups 1 and 2 (p > 0.05). In contrast, the TEs showed poorer SRTs than the NTEs in these two subject groups (p = 0.022 and 0.049). No inferiority of spectral/temporal resolution in TEs compared with NTEs suggests that there may be no more outer hair cell (OHC) damage on the tinnitus side given that damaged OHCs are associated with broadening the auditory filters. The decoupling of the SRT results from the spectral/temporal resolution data could imply that the occurrence of tinnitus does not depend upon the degree of damage to the OHCs, but rather upon different plastic changes in the central auditory system after cochlear damage. SIGNIFICANCE STATEMENT: We can easily find unilateral tinnitus patients who have symmetric hearing thresholds. Our research question was what kind of difference would be responsible for the tinnitus in the tinnitus-affected ears but not in the non-tinnitus ears of subjects with symmetric hearing thresholds. The answer to this fundamental question could help us to understand the pathophysiology of tinnitus. We evaluated the potential influence of tinnitus upon the subjects' auditory spectral and temporal resolution and speech perception in noise by comparing these psychoacoustic performances between tinnitus-affected ears and non-tinnitus ears in the same subjects.

Simultaneous versus Sequential Intratympanic Steroid Treatment for Severe-to-Profound Sudden Sensorineural Hearing Loss.

OBJECTIVES: Severe-to-profound sudden sensorineural hearing loss (SSNHL) has a poor prognosis. We aimed to compare the efficacy of simultaneous and sequential oral and intratympanic steroids for this condition. METHODS: Fifty patients with severe-to-profound SSNHL (>70 dB HL) were included from 7 centers. The simultaneous group (27 patients) received oral and intratympanic steroid injections for 2 weeks. The sequential group (23 patients) was treated with oral steroids for 2 weeks and intratympanic steroids for the subsequent 2 weeks. Pure-tone averages (PTA) and word discrimination scores (WDS) were compared before treatment and 2 weeks and 1 and 2 months after treatment. Treatment outcomes according to the modified American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) criteria were also analyzed. RESULTS: The improvement in PTA and WDS at the 2-week follow-up was 23 ± 21 dB HL and 20 ± 39% in the simultaneous group and 31 ± 29 dB HL and 37 ± 42% in the sequential group; this was not statistically significant. Complete or partial recovery at the 2-week follow-up was observed in 26% of the simultaneous group and 30% of the sequential group; this was also not significant. The improvement in PTA and WDS at the 2-month follow-up was 40 ± 20 dB HL and 37 ± 35% in the simultaneous group and 41 ± 25 dB HL and 48 ± 41% in the sequential group; this was not statistically significant. Complete or partial recovery at the 2-month follow-up was observed in 33% of the simultaneous group and 35% of the sequential group; this was also not significant. Seven patients in the sequential group did not need intratympanic steroid injections for sufficient improvement after oral steroids alone. CONCLUSIONS: Simultaneous oral/intratympanic steroid treatment yielded a recovery similar to that produced by sequential treatment. Because the addition of intratympanic steroids can be decided upon based on the improvement after an oral steroid, the sequential regimen can be recommended to avoid unnecessary intratympanic injections.

Analysis of impact noise induced by hitting of titanium head golf driver.

The hitting of titanium head golf driver against golf ball creates a short duration, high frequency impact noise. We analyzed the spectra of these impact noises and evaluated the auditory hazards from exposure to the noises. Noises made by 10 titanium head golf drivers with five maximum hits were collected, and the spectra of the pure impact sounds were studied using a noise analysis program. The noise was measured at 1.7 m (position A) and 3.4 m (position B) from the hitting point in front of the hitter and at 3.4 m (position C) behind the hitting point. Average time duration was measured and auditory risk units (ARUs) at position A were calculated using the Auditory Hazard Assessment Algorithm for Humans. The average peak levels at position A were 119.9 dBA at the sound pressure level (SPL) peak and 100.0 dBA at the overall octave level. The average peak levels (SPL and overall octave level) at position B were 111.6 and 96.5 dBA, respectively, and at position C were 111.5 and 96.7 dBA, respectively. The average time duration and ARUs measured at position A were 120.6 ms and 194.9 units, respectively. Although impact noises made by titanium head golf drivers showed relatively low ARUs, individuals enjoying golf frequently may be susceptible to hearing loss due to the repeated exposure of this intense impact noise with short duration and high frequency. Unprotected exposure to impact noises should be limited to prevent cochleovestibular disorders.

Clinical characteristics of persistent postural-perceptual dizziness and its visual subtype in Korean patients: A multicenter cross-sectional study.

OBJECTIVES: Persistent postural-perceptual dizziness (PPPD) is a chronic functional vestibular disorder for which the Bárány Society has established diagnostic criteria. This nationwide multicenter study aims to investigate the clinical features of individuals with definite PPPD and clinical variant PPPD who do not fully meet the diagnostic criteria, with a particular focus on visual exaggeration. METHODS: Between September 2020 and September 2021, a total of 76 individuals with definite PPPD and 109 individuals with clinical variant PPPD who did not meet all three exacerbating factors outlined in Criterion B were recruited from 18 medical centers in South Korea. The study gathered information on demographic factors, clinical manifestations, balance scales, and personality assessments. RESULTS: Comparative analysis between groups with definite PPPD and clinical variant with visual exacerbation revealed no significant differences in sociodemographic characteristics, clinical course, dizziness impact, and specific precipitants. Only disease duration was significantly longer in definite PPPD compared with variant with visual exacerbation. However, the variant without visual exacerbation displayed significantly reduced rates of panic disorder, diminished space-motion discomfort, lesser impact of dizziness, and decreased prevalence of depression when compared with the definitive PPPD. CONCLUSION: This is the first comprehensive nationwide study examining clinical features of both definite PPPD patients and its clinical variants, considering visual exacerbating factors. Differences in dizziness and personality traits emerged between definite PPPD and its potential variant without visual issues. Our results highlight the possibility of a distinct clinical variant of PPPD influenced by visual dependency.

Expression of the cysteinyl leukotriene 1 receptor and glucocorticoid receptor-ß in nasal polyps.

The objective of this study was to analyze the expression of cysteinyl leukotriene 1 (CysLT1) receptor and glucocorticoid receptors (GRs) in nasal polyps, and to evaluate the relationship between the expression of CysLT1 receptors and that of GRs. Nasal polyps were taken from 32 patients of chronic rhinosinusitis with nasal polyposis. Samples of middle turbinate from seven healthy subjects were used as controls. Specimens were immunohistochemically stained for CysLT1 receptor, GR-α and GR-ß receptor, and were quantified in the unit area of the tissues. Numbers of CysLT1 receptor-positive cells were much increased in nasal polyps than in middle turbinate (281 ± 67 vs. 157 ± 85 cells/mm(2), P = .01). There was no significant difference in the numbers of GR-α positive cells between nasal polyps and normal turbinate mucosa. GR-ß positive cells were increased in nasal polyps as compared to normal turbinate mucosa (36 ± 8 vs. 19 ± 7 cells/mm(2), P = .03). A significant relationship was found between the expression of CysLT1 receptor and GR-ß in nasal polyps (R = .525, P = .04), whereas there was no significant relationship between the expression of CysLT1 receptor and GR-α in nasal polyps. Our study shows that CysLT1 receptor expression predominates on GR-ß over-expressed polyps. This may suggest the additional effect of CysLT1 receptor antagonist for the treatment of nasal polyposis resistant to steroid alone.

Audiological and surgical evidence for the presence of a third window effect for the conductive hearing loss in DFNX2 deafness irrespective of types of mutations.

The objective of this study was to clarify the cause of the air-bone gap in incomplete partition (IP) type III cases according to the POU3F4 gene (DFNX2) mutation type. A retrospective analysis of patient medical records was done in a tertiary referral medical center. Five IP type III patients proved to be carrying a mutation in or affecting POU3F4. The hearing and the middle ear status at either exploratory tympanotomy or cochlear implantation from these DFNX2 cases was reviewed. Four of five unrelated IP type III patients harbored a point mutation of POU3F4 and the fifth patient carried a large genomic deletion upstream to POU3F4. Two of the four DFNX2 patients carrying a point mutation had moderate to severe mixed hearing loss with a substantial amount of air-bone gap. These patients underwent exploratory tympanotomy to identify the cause of their hearing loss. The other three patients, including one carrying a large deletion, had profound hearing loss at presentation and received a cochlear implant. In the exploratory tympanotomy group with a substantial amount of air-bone gap and a point mutation (n = 2), one patient had a perfect ossicular chain with normal mobility, a positive ipsilateral stapedial reflex, and a positive round window reflex. In the cochlear implantation group (n = 3), we found a stapes with normal mobility and a positive round window reflex in one patient who harbored a large genomic deletion upstream to POU3F4. We concluded that the probable presence of the third window effect is not limited to the particular type of POU3F4 mutation.

Personalized Neuromodulation: A Novel Strategy for Improving Tinnitus Treatment.

This study evaluated the efficacy of personalized neuromodulation, where treatment modalities are chosen based on the patient's responses in a pilot trial. A total of 71 patients with tinnitus were divided into two groups: a personalized group and a randomized neuromodulation group. In the personalized group (n = 35), repetitive transcranial magnetic stimulation (rTMS) and transcranial direct-current stimulation (tDCS) were assessed in a pilot trial, and responsive modalities were administered to 16 patients, while the non-responders (n = 19) were randomly assigned to rTMS, tDCS, or combined modalities. Patients in the randomized group (n = 36) were randomly allocated to rTMS, tDCS, or combined modalities. The Tinnitus Handicap Inventory (THI) score improvement after 10 sessions of each neuromodulation was significantly greater in the personalized group than in the randomized group (p = 0.043), with no significant differences in tinnitus loudness, distress, or awareness. The treatment success rate was highest in the personalized responder subgroup (92.3%), and significantly greater than that in the non-responder subgroup (53.0%; p = 0.042) and the randomized group (56.7%; p = 0.033). Personalized neuromodulation, where the treatment modality is chosen based on the patient's responses in a pilot trial, is an advantageous strategy for treating tinnitus.

Changes in the Mean and Variance of the Numbers of Medical Visits for Allergic Diseases before and during the COVID-19 Pandemic in Korea.

The implementation of precautionary measures, such as wearing a mask and social distancing, may have affected allergic diseases during the coronavirus disease 2019 (COVID-19) pandemic. This study aimed to compare the numbers of medical visits for allergic diseases before and during the COVID-19 pandemic. Data were obtained from the Korean National Health Insurance claims database. Monthly numbers of patients for four allergic diseases, i.e., allergic rhinitis (AR), asthma, atopic dermatitis (AD), and allergic conjunctivitis (AC), were evaluated using ICD-10 codes and compared between the 'before COVID-19' period from January 2018 to February 2020, and the 'during COVID-19' period from March 2020 to June 2021, since the first COVID-19 patient was detected on 20 January 2020, in Korea. Subgroup analyses were performed according to age and sex. The mean numbers of medical visits for AR and asthma were significantly greater before COVID-19 than those during COVID-19 (both p < 0.001). The variance in the number of medical visits for asthma decreased during the COVID-19 pandemic. However, the mean number of medical visits for AD increased slightly during COVID-19 and that for AC did not change before and during the COVID-19 pandemic. In subgroup analyses, the results showed a similar pattern to that of the total number of participants, regardless of age and sex. In conclusion, medical visits for AR and asthma significantly decreased during the COVID-19 pandemic, regardless of age and sex.

Coprevalence of Presbycusis and Its Effect on Outcome of Voice Therapy in Patients With Presbyphonia.

OBJECTIVE: To identify the coprevalence of presbycusis and presbycusis and analyze the effect of presbycusis on compliance and result of voice therapy in presbycusis patients. METHODS: This cross-sectional, prospective cohort study initially screened patients aged ≥65 years who visited our hospital from February 2019 to January 2020. Unaided pure tone audiometry was performed in these subjects to determine the presence of presbycusis. Perceptual voice assessment by an examiner was conducted for screening of presbycusis, and its diagnosis was confirmed through the voice handicap index-10 (VHI-10) questionnaire and a laryngoscopic exam. Patients with presbycusis underwent voice therapy and were assessed for their compliance and outcomes of the treatment according to the coexistence of presbycusis. RESULTS: Among the 221 patients, presbycusis and presbycusis were diagnosed in 125 (56.6%) and 110 (49.8%) patients, respectively. The copresence of these two disorders were identified in 87 (39.4%) patients, and there was a significant correlation between presbycusis and presbycusis. The effects of voice therapy were examined in the consecutive 40 patients who were diagnosed with presbycusis. There were 21 patients without presbycusis and 19 patients with presbycusis. The average pretreatment voice handicap index-10 score was significantly higher in presbycusis patients; there was no significant difference in the incidence of dropout from voice therapy between the groups. The patients without presbycusis showed a significant improvement in the functional communication measurement (FCM) level and maximum phonation time (MPT) compared with those of patients with presbycusis after voice therapy. CONCLUSIONS: Presbyphonia and presbycusis coexisted in many elderly people. The improvement in the FCM level and MPT after voice therapy was relatively low if patients with presbycusis accompanied by presbycusis. The copresence of presbycusis did not significantly affect compliance with voice therapy in the patients.

Long-Term Effects of Hearing Aid Use on Auditory Spectral Discrimination and Temporal Envelope Sensitivity and Speech Perception in Noise.

BACKGROUND: The aims of this study were to evaluate the long-term effects of hearing-aid use on auditory spectral discrimination, temporal envelope sensitivity, and speech perception ability and to determine whether hearing performance changes with the duration of hearing-aid use. METHODS: The study included 13 elderly participants (64.15 ± 9.87 years) who had used hearing-aids for 12 months in everyday life. We compared the auditory performance without hearing-aids at the time of pre-fitting with the auditory performance with hearing-aids at 1 month and 12 months after fitting. Three different psychoacoustic measurements were made at their most comfortable levels to exclude the effect of amplification: (1) spectral-ripple discrimination, (2) temporal modulation detection, and (3) speech recognition in white noise. RESULTS: Repeated-measures analysis of variance demonstrated that the duration of hearing-aid use significantly affected spectral-ripple discrimination thresholds and 100 Hz temporal modulation detection threshold (P < .05). Post hoc tests revealed that the improvements in spectral discrimination in the early post-fitting stage (1 month) did not seem to increase over the period of hearing-aid use, whereas the temporal envelope sensitivity improved continuously over time (up to 12 months). CONCLUSION: These results imply that hearing-aid users adapt to hearing-aid processing for spectral discrimination immediately, whereas they need time to adapt to hearing-aid processing for temporal envelope sensitivity. Alternatively, long-term hearing-aid use could induce positive plastic changes exclusively in terms of temporal envelope sensitivity.

Effect of face masks on speech perception in noise of individuals with hearing aids.

Although several previous studies have confirmed that listeners find it difficult to perceive the speech of face-mask-wearing speakers, there has been little research into how masks affect hearing-impaired individuals using hearing aids. Therefore, the aim of this study was to compare the effects of masks on the speech perception in noise of hearing-impaired individuals and normal-hearing individuals. We also investigated the effect of masks on the gain conferred by hearing aids. The hearing-impaired group included 24 listeners (age: M = 69.5, SD = 8.6; M:F = 13:11) who had used hearing aids in everyday life for >1 month (M = 20.7, SD = 24.0) and the normal-hearing group included 26 listeners (age: M = 57.9, SD = 11.1; M:F = 13:13). Speech perception in noise was measured under no mask-auditory-only (no-mask-AO), no mask-auditory-visual (no-mask-AV), and mask-AV conditions at five signal-to-noise ratios (SNRs; -16, -12, -8, -4, 0 dB) using five lists of 25 monosyllabic Korean words. Video clips that included a female speaker's face and sound or the sound only were presented through a monitor and a loudspeaker located 1 m in front of the listener in a sound-attenuating booth. The degree of deterioration in speech perception caused by the mask (no-mask-AV minus mask-AV) was significantly greater for hearing-impaired vs. normal-hearing participants only at 0 dB SNR (Bonferroni's corrected p < 0.01). When the effects of a mask on speech perception, with and without hearing aids, were compared in the hearing-impaired group, the degree of deterioration in speech perception caused by the mask was significantly reduced by the hearing aids compared with that without hearing aids at 0 and -4 dB SNR (Bonferroni's corrected p < 0.01). The improvement conferred by hearing aids (unaided speech perception score minus aided speech perception score) was significantly greater at 0 and -4 dB SNR than at -16 dB SNR in the mask-AV group (Bonferroni's corrected p < 0.01). These results demonstrate that hearing aids still improve speech perception when the speaker is masked, and that hearing aids partly offset the effect of a mask at relatively low noise levels.

The Relation of Sound Level Tolerance to Tinnitus Ears in Human.

BACKGROUND: The aim of this study was to evaluate the relationship between sound level tolerance and tinnitus in humans. METHODS: We compared the loudness discomfort levels at 500 and 3000 Hz pure tones in 33 subjects with bilateral tinnitus and 33 subjects with unilateral tinnitus with normal and symmetric hearing thresholds and those of age- and sex-matched control subjects. RESULTS: Both the tinnitus ears (108.18 ± 10.22 dB HL and 103.03 ± 11.04 dB HL) and non-tinnitus ears (108.94 ± 12.61 dB HL and 104.24 ± 11.60 dB HL) in the unilateral tinnitus subjects showed significantly lower loudness discomfort levels at 500 and 3000 Hz than the control ears (115.91 ± 6.78 dB HL and 111.52 ± 8.88 dB HL, P < .008; α=0.05/6=0.008), whereas there was no difference in the loudness discomfort levels of the tinnitus ears of the bilateral tinnitus subjects (111.52 ± 10.42 dB HL or 106.36 ± 11.34 dB HL) and the control ears. CONCLUSION: These results support the hypothesis that the reduced loudness discomfort levels in tinnitus subjects with normal and symmetric hearing thresholds are associated with a hidden injury to the cochlea that induces the development of tinnitus, especially on one side. Whether tinnitus is perceived unilaterally or bilaterally depends on the status of the auditory system, which may be reflected in the sound level tolerance and loudness discomfort levels.

Cochlear implantation for total deafness after ipsilateral ventriculoperitoneal shunt surgery: technical report.

BACKGROUND: Cochlear implantation (CI) becomes more challenging when a programmable ventriculoperitoneal (VP) shunt is present on the same side of the head. We report a successful ipsilateral CI in a patient who suffered bilateral hearing loss after shunt surgery. METHOD: We describe the CI case of a 49-year-old woman with an implanted VP shunt device, and perform a retrospective review of the clinical, audiological, and radiological features, surgical techniques, and postoperative functional outcomes. FINDINGS: During CI, the magnet in the core of internal antenna of the CI device was positioned approximately 8 cm from the shunt valve so that it would not be affected by the magnetic field of the programmable valve. Although the CI antenna tip and shunt catheter overlapped, we were very careful not to pull the shunt catheter out of position while the musculoperiosteal flap was elevated. CONCLUSIONS: The present result suggests that ipsilateral CI is an option for deaf adult patients who have a programmable shunt.

Within-Subject Comparisons of the Auditory Brainstem Response and Uncomfortable Loudness Levels in Ears With and Without Tinnitus in Unilateral Tinnitus Subjects With Normal Audiograms.

OBJECTIVE: To evaluate whether cochlear synaptopathy is a common pathophysiologic cause of tinnitus in individuals with normal audiograms. STUDY DESIGN: Prospective study. SETTING: Tertiary referral center. METHODS: We enrolled 27 subjects with unilateral tinnitus and normal symmetric hearing thresholds, and 27 age- and sex-matched control subjects with normal symmetric hearing thresholds. We measured 1) the amplitudes of waves I and V with 90 dB nHL click stimuli in quiet conditions; 2) the latency shift of wave V with 80 dB nHL click stimuli in background noise, varying from 40 dB HL to 70 dB HL; and 3) uncomfortable loudness levels (UCLs) at 500 Hz and 3000 Hz pure tones. RESULTS: There were no significant differences in the wave V/I amplitude ratio or the latency shift in wave V with increasing noise levels among the tinnitus ears (TEs), nontinnitus ears (NTEs), and control ears. There were no significant differences in UCLs at 500 Hz or 3000 Hz between TEs and NTEs, but the UCLs were lower in TEs (mean 111.3 dB or 104.1 dB) and NTEs (mean 109.4 dB or 100.6 dB) than in control ears (mean 117.9 dB or 114.1 dB, p < 0.017). No subject met our criteria for cochlear synaptopathy or increased central gain in terms of all three parameters. CONCLUSION: Based on these results for UCL, increased central gain is a major mechanism of tinnitus in humans with normal audiograms. However, this compensatory mechanism for reduced auditory input may originate from other pathophysiologic factors rather than from cochlear synaptopathy.

Predictive Factors for the Success of Intratympanic Dexamethasone Treatment of Acute Subjective Tinnitus.

OBJECTIVES: The purpose of this study was to determine the factors predicting the success or failure of intratympanic dexamethasone (ITD) injection in the treatment of acute subjective tinnitus (AST). MATERIALS AND METHODS: We enrolled patients who were treated with ITD within 3 months of the onset of tinnitus, between 2013 and 2017. We compared the clinical characteristics and audiological data of the patients in the cured group (n=38, 45.6±13.3 years old) and the nonresponder group (n=40, 48.9±18.6 years old). RESULTS: The cured group was predominantly female (p=0.002). The mean duration of tinnitus before ITD was shorter in the cured group than the nonresponder group (p=0.002). The pure-tone averages in both sides were lower in the cured group than in the nonresponder group (p=0.018). The time of tinnitus awareness was shorter in the cured group than in the nonresponder group (p=0.014). Multivariable analysis showed that the duration of tinnitus (odds ratio [OR]=1.045), a history of exposure to noise just before tinnitus development (OR=7.766), and distortion product otoacoustic emissions results (OR=4.580) predicted the outcome of ITD treatment in AST. CONCLUSION: A short duration of tinnitus, no history of immediate noise exposure, and normal distortion product otoacoustic emissions could be favorable prognostic factors for AST treated with ITD injection.

Influence of Cochlear Dead Regions on Hearing Outcome in Sudden Sensorineural Hearing Loss.

OBJECTIVE: The aims of this multicenter study were to prospectively evaluate the prevalence of dead regions (DRs) in sudden sensorineural hearing loss (SSNHL) and compare the clinical characteristics and hearing outcomes of SSNHL according to the presence of DRs. STUDY DESIGN: Prospective study. SETTING: Multicenter study. PATIENTS AND METHODS: The threshold-equalizing noise (TEN) test was prospectively performed on a total of 130 patients diagnosed with SSNHL. All patients received systemic steroid therapy and/or intratympanic steroid injection within 1 month after onset. Pure-tone audiograms and the TEN test were conducted before and after steroid treatment. Age, sex, side of affected ear, recurrence, onset of symptoms, presence of dizziness, and comorbid diseases were also collected. The prevalence of DRs in SSNHL and clinical factors related to the DRs were assessed. Hearing outcomes for SSNHL according to DRs were evaluated in 68 patients who followed a pure-tone audiogram. RESULTS: The overall prevalence of one or more DRs in SSNHL evaluated using the TEN test was 20.8% (27/130 subjects) and the overall frequency-specific prevalence of DR was 6.7% (61/910 DRs). Although the DRs (+)and DR (-) groups had similar initial pure-tone thresholds, the DRs (+) group had significantly worse initial WRS compared to the DRs (-) group (p = 0.015). The presence of DRs was not associated with hearing recovery in a multivariate logistic regression model, but it was significantly associated with the degree of hearing gain in a multivariate linear regression model (p = 0.018). CONCLUSIONS: The presence of DRs can be considered one of the poor prognostic factors for SSNHL and the TEN test may contribute to assess the prognosis of SSNHL in clinical settings.

Further Beneficial Effect of Hearing Aids on Speech Recognition Performance Besides Amplification: Importance of the Restoration of Symmetric Hearing.

OBJECTIVE: To identify the improvement in auditory spectral resolution, temporal resolution, and speech recognition conferred with various hearing-aid (HA) technologies when the amplification effect of the HA is excluded, and to compare the beneficial effects depending on the restoration of symmetric hearing with different amplification settings in various hearing impairment conditions. STUDY DESIGN: Prospective study. SETTING: Tertiary referral center. SUBJECTS: Sixty-two subjects who had used HAs for more than 3 months were divided into four groups: group 1, bilateral HAs (n = 28); group 2, unilateral HA in the better ear (n = 12); group 3, unilateral HA in the worse ear (n = 12); group 4, unilateral HA with symmetric hearing thresholds (n = 10). METHODS: Aided performance and unaided performance were compared in each group. Four different psychoacoustic measurements were made: 1) spectral ripple discrimination; 2) temporal modulation detection; 3) speech recognition threshold in white noise; and 4) speech discrimination score (SDS) under quiet conditions. All test signals were presented by a loudspeaker located 1 m in front of the subject in a sound-attenuating booth, at their most comfortable levels, with or without HAs. RESULTS: In group 1, the use of HAs significantly improved both SDS under quiet conditions and speech recognition in noise compared with the unaided condition. Group 2 showed better SDS under quiet conditions with HAs, and group 3 showed improved speech recognition in noise with HAs. In contrast, in group 4, no measurements differed with or without HAs. CONCLUSIONS: These results demonstrate the benefits of HAs on speech perception in noise, in addition to their amplification effect, but only when HA restores symmetric hearing.

Vestibular Manifestations in Subjects With Enlarged Vestibular Aqueduct.

OBJECTIVE: To describe the results of a thorough evaluation in a large series of patients with an enlarged vestibular aqueduct (EVA), focusing on vestibular manifestations with etiological considerations. STUDY DESIGN: Retrospective chart review of patients with EVA. SETTING: Tertiary referral center. PATIENTS: A total of 22 EVA patients with a median age of 8 years (6 mo-35 yr) who underwent both audiovestibular and radiologic examinations. MAIN OUTCOME MEASURES: Patient demographics, radiologic findings, audiologic results, vestibular symptoms, findings of neurotologic examinations, and laboratory evaluations were collected and analyzed. Standard descriptive statistics were used to summarize patient characteristics. Subjects who had a history of vertigo attack were categorized as "vestibulopathy group," while subjects without any history of vertigo as "non-vestibulopathy group." RESULTS: Of the 41 ears included, 37 (90.2%) had hearing loss on initial audiometric evaluations. Among the 22 patients, 14 (63.6%) complained of dizziness. Of the 14 vertiginous patients, seven had recurrent episodes, five had a history of single attack, and two presented with postural imbalances. There were no significant differences between vestibulopathy and non-vestibulopathy groups with regard to the relationship between the development of vestibular symptoms and aqueductal size, hearing threshold, or age at first visit. Four of the 22 (18.2%) patients developed secondary benign paroxysmal positional vertigo (BPPV) and all patients complained of simultaneous decreases in hearing. CONCLUSIONS: Our results demonstrate that patients may develop vestibular symptoms during their clinical course, and all patients with an enlarged vestibular aqueduct should be cautioned regarding the potential development of vestibular pathology. Moreover, the non-negligible incidence of secondary BPPV mandates positional tests when evaluating EVA patients with vertigo.

Comparison of Long-Term Outcome of Intratympanic Dexamethasone Therapy between Acute Noise-Induced Tinnitus and Acute Idiopathic Tinnitus.

OBJECTIVE: To compare the long-term outcomes of acute noise-induced tinnitus (ANT) and acute idiopathic tinnitus (AIT) to intratympanic dexamethasone (ITD) therapy. MATERIALS AND METHODS: Patients treated for tinnitus occurring immediately after noise exposure comprised the ANT group (n=20) and patients treated for idiopathic tinnitus comprised the AIT group (n=39). All patients were treated with ITD within 3 months of the onset of tinnitus. Quantitative assessment of the improvement in tinnitus using questionnaires and changes in hearing thresholds were compared between the two groups. RESULTS: Mean follow-up durations were 75.90±69.83 weeks in the ANT group and 93.41±101.43 weeks in the AIT group. Patients with ANT were younger in age than those with AIT (38.30±18.28 vs. 53.56±14.08, p=0.00) and were predominately male (Male: Female, M:F 13:7 vs. 13:26, p=0.02, respectively). The subjective tinnitus loudness, time of tinnitus awareness, and Tinnitus Handicap Inventory score improved in both groups, although the changes in these parameters were not significantly different between the groups. The cure and overall improvement rates of the ANT group were and 10.00% and 25.00%, respectively. The cure and overall improvement rates of the AIT groups were 25.64% and 35.90%, respectively and there were no significant differences between the two groups in terms of the cure and overall improvement rates (p=0.19 and 0.40, respectively). CONCLUSION: The long-term outcome in terms of control of tinnitus with ITD in the ANT group was similar to that in the AIT group. Thus, ITD injection may be a useful treatment option for acute tinnitus caused by noise trauma.

Comparisons of auditory brainstem response and sound level tolerance in tinnitus ears and non-tinnitus ears in unilateral tinnitus patients with normal audiograms.

OBJECTIVE: Recently, "hidden hearing loss" with cochlear synaptopathy has been suggested as a potential pathophysiology of tinnitus in individuals with a normal hearing threshold. Several studies have demonstrated that subjects with tinnitus and normal audiograms show significantly reduced auditory brainstem response (ABR) wave I amplitudes compared with control subjects, but normal wave V amplitudes, suggesting increased central auditory gain. We aimed to reconfirm the "hidden hearing loss" theory through a within-subject comparison of wave I and wave V amplitudes and uncomfortable loudness level (UCL), which might be decreased with increased central gain, in tinnitus ears (TEs) and non-tinnitus ears (NTEs). SUBJECTS AND METHODS: Human subjects included 43 unilateral tinnitus patients (19 males, 24 females) with normal and symmetric hearing thresholds and 18 control subjects with normal audiograms. The amplitudes of wave I and V from the peak to the following trough were measured twice at 90 dB nHL and we separately assessed UCLs at 500 Hz and 3000 Hz pure tones in each TE and NTE. RESULTS: The within-subject comparison between TEs and NTEs showed no significant differences in wave I and wave V amplitude, or wave V/I ratio in both the male and female groups. Individual data revealed increased V/I amplitude ratios > mean + 2 SD in 3 TEs, but not in any control ears. We found no significant differences in UCL at 500 Hz or 3000 Hz between the TEs and NTEs, but the UCLs of both TEs and NTEs were lower than those of the control ears. CONCLUSIONS: Our ABR data do not represent meaningful evidence supporting the hypothesis of cochlear synaptopathy with increased central gain in tinnitus subjects with normal audiograms. However, reduced sound level tolerance in both TEs and NTEs might reflect increased central gain consequent on hidden synaptopathy that was subsequently balanced between the ears by lateral olivocochlear efferents.