The Effect of Long-Term Unilateral Deafness on Auditory Performance / 대한이비인후과학회지

Background and Objectives@#We investigated whether there are differences in auditory performance between the healthy ears of subjects with unilateral deafness (UD) and the control ears of subjects with normal hearing (NH) in both ears.Subjects and Method Sixteen subjects with acquired UD and 16 subjects with NH thresholds for both ears were enrolled. We compared the auditory performance of UD group and control group with NH in both ears. @*Results@#We found no meaningful differences in the three measures of psychoacoustic performance between the total healthy ears of subjects with UD and the ears of the control group. However, in the subgroup comparison, the left ears of subjects with right UD showed significantly poorer spectral-ripple discrimination (SRD) than the right ears of the subjects with left UD (p=0.006) and the ears of control subjects with NH (p=0.004). @*Conclusion@#Our findings indicate that after unilateral auditory deprivation, auditory processing is differentially affected by the side involved. In the subjects with acquired UD, the longterm hearing deprivation on the right side induced the down-regulation of central auditory process for SRD, but hearing deprivation on the left side did not affect SRD.

Effect of Digital Noise Reduction of Hearing Aids on Music and Speech Perception

Background and Objectives@#Although many studies have evaluated the effect of the digital noise reduction (DNR) algorithm of hearing aids (HAs) on speech recognition, there are few studies on the effect of DNR on music perception. Therefore, we aimed to evaluate the effect of DNR on music, in addition to speech perception, using objective and subjective measurements. @*Subjects and Methods@#Sixteen HA users participated in this study (58.00±10.44 years; 3 males and 13 females). The objective assessment of speech and music perception was based on the Korean version of the Clinical Assessment of Music Perception test and word and sentence recognition scores. Meanwhile, for the subjective assessment, the quality rating of speech and music as well as self-reported HA benefits were evaluated. @*Results@#There was no improvement conferred with DNR of HAs on the objective assessment tests of speech and music perception. The pitch discrimination at 262 Hz in the DNR-off condition was better than that in the unaided condition (p=0.024); however, the unaided condition and the DNR-on conditions did not differ. In the Korean music background questionnaire, responses regarding ease of communication were better in the DNR-on condition than in the DNR-off condition (p=0.029). @*Conclusions@#Speech and music perception or sound quality did not improve with the activation of DNR. However, DNR positively influenced the listener’s subjective listening comfort. The DNR-off condition in HAs may be beneficial for pitch discrimination at some frequencies.

Translation and Linguistic Validation of Korean Version of Musical Background Questionnaire / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES@#The Musical Background Questionnaire (MBQ) has been developed to assess formal musical training and listening enjoyment. The aims of this study were to translate MBQ into Korean with subsequent linguistic validation and to evaluate the effectiveness of the Korean version of MBQ (K-MBQ).SUBJECTS AND METHOD: Between 2013 and 2014, a panel affiliated with the questionnaire committee of the Korean Audiological Society reconciled the first draft K-MBQ translated by a bilingual person. A separate bilingual translator, who had never seen the original MBQ, translated the draft K-MBQ back into English, and subsequently, the panel reviewed its equivalence to the original one. K-MBQ was administered to 29 adults (M:F=15:14; aged 21 to 76 years) for cognitive debriefing. Pure tone and speech audiometry were performed in all participants.@*RESULTS@#The translation of K-MBQ was completed through a multi-step process of forward translation, reconciliation, reverse translation, cognitive debriefing and proofreading. Thirteen (45%) of 29 subjects reported formal musical training, and 16 participants (55%) judged themselves as having no musical education and background. No significant correlation was found between musical background and hearing level, whereas self-perceived quality of music and self-perception of music elements quantified by K-MBQ were associated with hearing ability in terms of pure-tone and speech audiometry.@*CONCLUSION@#K-MBQ was translated and linguistically validated. The use of this questionnaire can provide further evaluation of musical background in patients with hearing loss or cochlear implant users.

Prevalence of Superior Semicircular Canal Dehiscence in Coronal Images of Temporal Bone Computed Tomography and Its Diagnostic Value in Korean Population / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: This study aimed to analyze the prevalence of superior semicircular canal dehiscence (SSCD) in the coronal images of high-resolution temporal bone computed tomography (TBCT) and to evaluate the diagnostic accuracy of coronal images for SSCD syndrome. SUBJECTS AND METHOD: We retrospectively reviewed high-resolution TBCT scans of 217 patients (434 ears) with SSCD due to various causes. The dehiscence ratio (slices showing dehiscence/total slices showing the superior semicircular canal) in the coronal images of TBCT was calculated, and the optimal cutoff value for the diagnosis of SSCD syndrome was determined using the receiver operating characteristics (ROC) curve. RESULTS: Of the 434 ears, 64 (14.7%) presented SSCD in more than one slice of the coronal images of TBCT, but only three patients (0.7%) were confirmed with SSCD syndrome. Based on the ROC curve analysis for the dehiscence ratio of 64 ears, the optimal cutoff value for the diagnosis of SSCD syndrome was 0.67 with 100% sensitivity and 90.2% specificity. CONCLUSION: The majority of cases diagnosed with SSCD syndrome using the coronal images of TBCT were asymptomatic or false-positive. The dehiscence ratio in the coronal images of TBCT combined with a typical symptom can be a highly sensitive and specific diagnostic tool for SSCD syndrome.

Significance of 125 Hz Pure-Tone Thresholds for Dizzy Patients with Low Frequency Sensorineural Hearing Loss / 대한평형의학회지

OBJECTIVES: To measure 125 Hz pure-tone thresholds in patients with low frequency sensorineural hearing loss (LFHL) and vertigo and to evaluate the necessity of 125 Hz thresholds for assessment of LFHL with vertigo. METHODS: Pure tone audiometry including 125 Hz was performed in 25 dizzy patients with LFHL ≤500 Hz and 25 age-matched subjects with normal hearing. Patients with sudden sensorineural hearing loss and vertigo were excluded. Comparison of 125 Hz between LFHL and control groups, and comparison of 125 Hz and other frequencies in LFHL group was made. RESULTS: Mean pure-tone thresholds at 125 Hz in LFHL group (41.7±7.5 dB) was higher than that in normal controls (12.8±6.4 dB). Three (12%) patients had normal thresholds at 125 Hz in LFHL group, whereas all subjects showed normal at 125 Hz in control group. None with average hearing thresholds at 250 and 500 Hz ≥35 dB had normal threshold at 125 Hz. There was a significant correlation between 125 Hz and other low frequencies in LFHL group (250 Hz; r=0.79, 500 Hz; r=0.66). CONCLUSIONS: Not every patient of LFHL with vertigo has abnormal hearing threshold at 125 Hz, although all subjects with normal hearing is within normal limits at 125 Hz. Measurement of 125 Hz pure-tone threshold is highly recommended when a mild LFHL exists.

Intratympanic Steroid Treatment versus Intratympanic Steroid and Diuretics Combination Treatment in Patients with Acute Low Frequency Sensorineural Hearing Loss with Vertigo / 대한평형의학회지

OBJECTIVES: Intratympanic dexamethasone (ITD) is a standard treatment for patients with sudden sensorineural hearing loss. The aim of this study was to evaluate the effectiveness of ITD vs. combination of ITD and diuretics for acute low frequency sensorineural hearing loss (LFHL) with vertigo. METHODS: A total 31 patients with LFHL that had developed within previous 2 weeks were enrolled and categorized into two groups: treated with ITD four times on 4 consecutive days (ITD group; 17 patients) and treated with ITD in the same way and diuretics orally for 2 weeks (combination group; 14 patients). After 6 months, we analyzed treatment outcomes using subjective improvement and audiometric change. RESULTS: Hearing thresholds at low frequencies ≤500 Hz were significantly improved in both ITD only and combination group (p0.05). For subjective symptoms, there were no significant differences of improvement rate in both groups (combination 64.3% vs. ITD only 64.7%, p>0.05). In pure tone audiometry, the improvement rate of combination group was not significantly different from that of ITD only group (71.4% vs. 76.5%, p>0.05). There was a significant correlation between the complete recovery rate and duration of symptoms. CONCLUSION: ITD alone is an effective treatment modality for acute LFHL with vertigo within 2 weeks of development. Combined ITD and diuretics have no additive effect for the recovery of hearing in patients with LFHL.

Significance of 125 Hz Pure-Tone Thresholds for Acute Low Frequency Sensorineural Hearing Loss / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: To analyze the 125 Hz pure-tone thresholds in patients with acute low frequency sensorineural hearing loss (LFHL) and to investigate the value of 125 Hz thresholds for the assessment of LFHL. SUBJECTS AND METHOD: Hearing tests including 125 Hz pure-tone were performed in 91 patients with acute LFHL ≤500 Hz and in 46 subjects with normal hearing. Patients with sudden sensorineural hearing loss or Meniere's disease were excluded. Inter-group and intra-group comparison of 125 Hz was made between LFHL and the control groups. RESULTS: There was a significant difference of mean pure-tone thresholds at 125 Hz between the acute LFHL and the normal groups (39.8±8.9 vs. 14.3±6.7 dB). Eight (8.8%) patients in the LFHL group showed normal thresholds at 125 Hz, but all other subjects were normal at 125 Hz in the control group. None with the average hearing thresholds at 250 and 500 Hz ≥40 dB had normal threshold at 125 Hz. There was a significant correlation between 125 Hz and other low frequencies in the LFHL group (250 Hz; r=0.81, 500 Hz; r=0.63). CONCLUSION: Not all patients with acute LFHL show abnormal hearing threshold at 125 Hz although every subject with normal hearing is within the normal limits at 125 Hz. Threshold assessment should be made at 125 Hz when a mild LFHL exists in the conventional pure tone audiometry.

The Normative Value of Acceptable Noise Level Test for Korean Young Listeners with Normal Hearing and Its Relationship with Auditory Brainstem Response Latency / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Acceptable noise level (ANL) test has been developed as a method to measure the background noise acceptance when listening to speech presented at the most comfortable level. The study was aimed to investigate normal-hearing in young subjects’ performance on ANL test and to evaluate the relationship between ANL and auditory evoked potentials. SUBJECTS AND METHOD: Fifty-three young adults (23 male and 30 female; aged 21 to 39 years) with normal hearing participated in this study. ANL and auditory brainstem response (ABR) tests were administered to subjects who were certified by pure tone audiometry that they had normal hearing threshold. RESULTS: The ANL test showed a large inter-subject variability in the acceptance of back-ground noise, ranging from -5 to 15 dB with the mean of ANL of 5.0±4.1 dB (4.5±4.5 dB in male and 5.4±3.8 dB in female). The mean most comfortable listening level was 35.2±5.3 dB, and the mean background noise level was 30.2±6.1 dB. There were no significant differences between male and female in the parameters of ANL test. There were no differences between the subjects with low versus high ANLs and ABR latencies. CONCLUSION: We obtained the normative data of the ANL test administered to Korean young adults with normal hearing. There is no relationship between ANL and the latency of ABR in this study population.

Intratympanic Steroid Injection in Tinnitus Management / 한양의대학술지

Intratympanic (IT) steroid injection has been used increasingly in various inner ear diseases instead of systemic steroid, because of the higher concentration of the drug into the target organ and the lower risk of the systemic side effect. Although there were several trials applying IT steroid injection on tinnitus, most of them failed to demonstrate its therapeutic effect more than controls. However, a study has shown a meaningful outcome when the therapeutic target is limited to acute tinnitus developed within 3 months. Although IT steroid injection treatment in tinnitus requires more evidence, when the therapeutic target is limited to the acute phase, IT steroid injection could be a treatment option for tinnitus. Early intervention, asymmetric hearing loss and unilateral tinnitus seem to be favorable factors for outcome of IT steroid injection.

Neuroglial Choristoma of the Middle Ear with Massive Tympanosclerosis: A Case Report and Literature Review

Neuroglialchoristoma is a rare cerebral heterotopia typically involving extracranial midline structures of the head and neck, including the nose, nasopharynx and oral cavity. It rarely involves non-midline structures, such as the middle ear, mastoid and orbit. We report the case of a 63-year-old woman with right-sided hearing loss and aural fullness who was diagnosed with neuroglialchoristoma of the middle ear and mastoid. To our knowledge, this is the first report on neuroglialchoristomawith massive tympanosclerosis. The presence of combination supported the inhalation theory of neuroglialchoristoma, given that tympanosclerosis is typically caused by Eustachian tube dysfunction.

Intratympanic Steroid and Oral Diuretics Combination Therapy for Acute Low Frequency Sensorineural Hearing Loss without Vertigo / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: The effectiveness of intratympanic dexamethasone injections (ITD) alone is compared against the combination therapy of ITD and oral diuretics as treatments for acute low frequency sensorineural hearing loss (LFHL) without vertigo. SUBJECTS AND METHOD: A total of 36 patients, with LFHL 0.05). For subjective symptoms, there were no statistically significant differences in the improvement rate in either group (combination 58.8% vs. ITD only 63.2%, p>0.05). In pure tone audiometry, the improvement rate of the combination group was not significantly different from that of the ITD only group (76.5% vs. 73.7%, p>0.05). There was a significant correlation between the complete recovery rate and duration of symptoms. CONCLUSION: ITD alone is an effective treatment modality for LFHL within 1 month after onset. Diuretics have no additive effect for the recovery of hearing in patients with acute LFHL without vertigo.

The Effect of High Frequency Sensorineural Hearing Loss on Auditory Temporal Resolution: Gaps-In-Noise Test Performance in Older and Young Adults with Normal Hearing / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Auditory temporal resolution, which refers to the time-related aspects of acoustic processing, can be evaluated by the Gaps-In-Noise (GIN) test. We investigated whether the presence of high frequency sensorineural hearing loss (HF-SNHL) affects the temporal resolution of GIN performance in older adults with normal hearing. SUBJECTS AND METHOD: Hearing tests including the GIN test were performed in 87 subjects with normal pure tone average. The GIN threshold and percentage of correct answers were compared among 4 groups of participants; older adults with normal hearing (n=18), older adults with HF-SNHL (n=24), young adults with normal hearing (n=24) and young adults with HF-SNHL (n=21). RESULTS: There was no significant difference in the mean GIN thresholds between the HF-SNHL group (5.8+/-0.8 msec) and the normal hearing group (6.0+/-0.8 msec) in older adults, whereas the mean GIN thresholds of HF-SNHL group was higher than that of the normal group in young adults (4.6+/-0.3 msec vs. 4.2+/-0.5 msec, p<0.05). The mean percentage of correct answers of HF-SNHL group (62.5+/-5.5%) was not significantly different from that of the normal hearing group (60.6+/-3.9%) in the old, unlike in the young (71.3+/-4.0% with HF-SNHL vs. 76.9+/-4.3% with normal hearing, p<0.05). Age only showed a significant correlation with the GIN performance. Neither the GIN threshold nor the GIN perception level had any relation with the presence of HF-SNHL in older adults. CONCLUSION: We found no evidence that supported the influence of HF-SNHL on auditory temporal resolution in older adults. These results imply that HF-SNHL may be of little importance in gap detection after age-related changes in central auditory system.

Fatal Case of Klebsiella Meningitis Combined with Bilateral Sudden Sensorineural Hearing Loss: A Case Report and Literature Review / 대한이비인후과학회지

Bilateral sudden sensorineural hearing loss (SSNHL) is very uncommon. Unlike unilateral SSNHL, bilateral SSNHL is more closely associated with serious systemic diseases and shows a more severe degree of hearing loss, poorer hearing prognosis and more significant impairment in morbidity. Although meningitis is one of possible causes of bilateral SSNHL, only a few cases were reported. We present a case of fatal Klebsiella meningitis accompanied by bilateral SSNHL with a literature review.

Feasibility and Safety of Transcutaneous Vagus Nerve Stimulation Paired with Notched Music Therapy for the Treatment of Chronic Tinnitus

BACKGROUND AND OBJECTIVES: A recent study demonstrated that tinnitus could be eliminated by vagus nerve stimulation (VNS) paired with notched sounds in a rat tinnitus model. The aims of this clinical study were to investigate the effects and safety of transcutaneous VNS (tVNS) by patch-type electrode paired with notched music for treating chronic tinnitus. SUBJECTS AND METHODS: Thirty patients with refractory chronic tinnitus for >12 months were included in this study. A patch-type electrode was attached to the auricular concha of the patient's left ear and tVNS was performed for 30 min (pulse rate 25 Hz, pulse width 200 micros, and amplitude 1-10 mA) using a transcutaneous electric nerve stimulation eco2. During tVNS, the patients listened to notched music cleared of the frequency spectrum corresponding to the tinnitus with a 0.5 octave notch width. RESULTS: After 10 treatment sessions, 15/30 patients (50%) reported symptom relief in terms of a global improvement questionnaire. The mean tinnitus loudness (10-point scale) and the mean tinnitus awareness score (%) improved significantly from 6.32+/-2.06 to 5.16+/-1.52 and from 82.40+/-24.37% to 65.60+/-28.15%, respectively (both p<0.05). None of the patients had any specific side effects, such as changes in heart rate or blood pressure. CONCLUSIONS: This study has demonstrated the feasibility and safety of tVNS paired with notched music therapy in patients with chronic tinnitus, with the use of a pad-type electrode attached to the auricular concha.

Noise-Induced Hearing Loss / 한양의대학술지

Noise-induced hearing loss (NIHL) is the second most common cause of permanent hearing impairment after age-related hearing loss. NIHL is influenced by environmental and genetic factors and the effects of noise can be exacerbated by the administration of ototoxic drugs or exposure to chemicals. The pathophysiology of NIHL is classified as either mechanical injury or metabolic (or biochemical) injury. Exposure of cochleae to intense sounds has been found to disrupt the stereocilia on the hair cells by separating the tip links and to depolymerize actin filaments, resulting in a disturbance in signal transduction. Major mechanisms of metabolic injuries include accumulation of reactive oxygen species enhanced by oxidative stress, cochlear ischemia followed by reperfusion injury, and excitotoxicity to auditory neuron induced by excessive release of the cochlear afferent neurotransmitter, glutamate. Many studies involving therapeutic or preventive trial with antioxidants, JNK inhibitors, and NMDA antagonists have shown partial effectiveness. However, protection from noise before cochlear injury occurs is very important because damaged hair cells and auditory neurons in the mammalian cochleae are unable to regenerate.

Comparison of the Effectiveness of Monitoring Cisplatin-Induced Ototoxicity with Extended High-Frequency Pure-Tone Audiometry or Distortion-Product Otoacoustic Emission

BACKGROUND AND OBJECTIVES: To compare the effectiveness of monitoring cisplatin-induced ototoxicity in adult patients using extended high-frequency pure-tone audiometry (EHF-PTA) or distortion-product otoacoustic emission (DP-OAE) and to evaluate the concurrence of ototoxicity and nephrotoxicity in cisplatin-treated patients. SUBJECTS AND METHODS: EHF-PTA was measured at frequencies of 0.25, 0.5, 1, 2, 3, 4, 6, 8, 9, 11.2, 12.5, 14, 16, 18, and 20 kHz and DP-OAE at frequencies of 0.5, 0.75, 1, 1.5, 2, 3, 4, 6, and 8 kHz in cisplatin-treated patients (n=10). Baseline evaluations were made immediately before chemotherapy and additional tests were performed before each of six cycles of cisplatin treatment. Laboratory tests to monitor nephrotoxicity were included before every cycle of chemotherapy. RESULTS: Four of 10 patients showed threshold changes on EHF-PTA. Five of 10 patients showed reductions in DP-OAE, but one was a false-positive result. The results of EHF-PTA and DP-OAE were consistent in two patients. Only one patient displayed nephrotoxicity on laboratory tests after the third cycle. CONCLUSIONS: In our study, the incidence rate of cisplatin-induced ototoxicity was 40% with EHF-PTA or DP-OAE. Although both EHF-PTA and DP-OAE showed the same sensitivity in detecting ototoxicity, they did not produce the same results in all patients. These two hearing tests could be used to complement one another. Clinicians should use both tests simultaneously in every cycle of chemotherapy to ensure the detection of ototoxicity.

The Effects of Unilateral Tinnitus on Auditory Temporal Resolution: Gaps-In-Noise Performance

BACKGROUND AND OBJECTIVES: The Gaps-In-Noise (GIN) test is a measure to assess auditory temporal resolution, which is the ability to follow rapid changes in the envelope of a sound stimulus over time. We investigated whether unilateral tinnitus affects temporal resolution by the GIN performance. SUBJECTS AND METHODS: Hearing tests including the GIN test were performed in 120 ears of 60 patients with unilateral tinnitus who showed symmetric hearing within 20 dB HL difference up to 8 kHz (tinnitus-affected ears, 14.6+/-11.2 dB HL; non-tinnitus ears 15.1+/-11.5 dB HL) and 60 ears of 30 subjects with normal hearing. Comparisons were made between tinnitus and non-tinnitus side of patients and normal ears of controls. RESULTS: There was no significant difference of the mean GIN thresholds among tinnitus-affected ears (5.18+/-0.6 ms), non-tinnitus ears (4.98+/-0.6 ms) and normal ears (4.97+/-0.8 ms). The mean percentage of correct answers in tinnitus side (67.3+/-5.5%) was slightly less than that in non-tinnitus side (70.0+/-5.5%) but it was not significantly different from that in normal ears (69.4+/-7.5%). Neither the GIN threshold nor the GIN perception level in tinnitus ears has relation to sex, frequency and loudness of tinnitus, and audiometric data. Age only showed a significant correlation with the GIN performance. CONCLUSIONS: We found no evidence which supported the influence of unilateral tinnitus on auditory temporal resolution. These results imply that tinnitus may not simply fill in the silent gaps in the background noise.

Time Course of the Suppression Effect on Transient Evoked Otoacoustic Emissions by Prolonged Contralateral Acoustic Stimulation

BACKGROUND AND OBJECTIVES: Although the suppressive effect of the medial efferent acoustic reflex is well known, the time course of this effect over prolonged periods has yet to be fully evaluated. We assessed time-dependent change in the suppression of transient evoked otoacoustic emissions (TEOAEs) by the medial efferent acoustic reflex over a relatively long period. SUBJECTS AND METHODS: We measured TEOAEs in the right ear before contralateral acoustic stimulation (CAS), and then measured serial TEOAEs in the right ear at four intervals during a total of 16 minutes of continuous CAS, followed by three more recordings after termination of CAS. RESULTS: TEOAE amplitudes were reduced with CAS during a certain period (from the immediate period to 10 minutes depending on frequency) and subsequently recovered. TEOAE suppression values in the mean amplitudes for overall frequency were 0.76 dB at the initial recording, 0.35 dB at 5 minutes, 0.44 dB at 10 minutes, and 0.33 dB at 15 minutes during CAS. The initial suppression value was significantly larger than other suppression values of 5, 10, and 15 minutes (p<0.05). In recordings obtained after CAS, TEOAE amplitude exceeded pre-acoustic amplitudes at 1 kHz, 1.5 kHz, and 2 kHz. CONCLUSIONS: The present results show the existence of the medial efferent acoustic reflex and demonstrate the time course that TEOAE suppressions present initially after CAS, showing fatigue over time. Overshooting of TEOAE was observed in recordings at several frequencies after termination of CAS.

Time Course of the Suppression Effect on Transient Evoked Otoacoustic Emissions by Prolonged Contralateral Acoustic Stimulation

BACKGROUND AND OBJECTIVES: Although the suppressive effect of the medial efferent acoustic reflex is well known, the time course of this effect over prolonged periods has yet to be fully evaluated. We assessed time-dependent change in the suppression of transient evoked otoacoustic emissions (TEOAEs) by the medial efferent acoustic reflex over a relatively long period. SUBJECTS AND METHODS: We measured TEOAEs in the right ear before contralateral acoustic stimulation (CAS), and then measured serial TEOAEs in the right ear at four intervals during a total of 16 minutes of continuous CAS, followed by three more recordings after termination of CAS. RESULTS: TEOAE amplitudes were reduced with CAS during a certain period (from the immediate period to 10 minutes depending on frequency) and subsequently recovered. TEOAE suppression values in the mean amplitudes for overall frequency were 0.76 dB at the initial recording, 0.35 dB at 5 minutes, 0.44 dB at 10 minutes, and 0.33 dB at 15 minutes during CAS. The initial suppression value was significantly larger than other suppression values of 5, 10, and 15 minutes (p<0.05). In recordings obtained after CAS, TEOAE amplitude exceeded pre-acoustic amplitudes at 1 kHz, 1.5 kHz, and 2 kHz. CONCLUSIONS: The present results show the existence of the medial efferent acoustic reflex and demonstrate the time course that TEOAE suppressions present initially after CAS, showing fatigue over time. Overshooting of TEOAE was observed in recordings at several frequencies after termination of CAS.

Is Cognitive Function in Adults with Hearing Impairment Improved by the Use of Hearing Aids?

OBJECTIVES: In the present study, we investigated whether speech-related cognitive function and speech recognition ability under background noise in adults with hearing impairment are improved with the use of hearing aids. METHODS: Participants were recruited from the ENT Department of Eulji Hospital from September 2008 to July 2009. The study group comprised 18 participants (mean age, 69.5+/-8.3 years) with sensorineural hearing loss who were fitted with hearing aids, and the control group comprised 11 participants of equivalent age (mean age, 63.1+/-11.8 years) who were not fitted with hearing aids. All participants were assessed using the computerized Korean visual verbal learning test (VVLT) and words-in-noise (WIN) test prior to fitting of hearing aids for the study group and initially for the control group. Both groups were reassessed in both tests after 6 months. For each group, differences in the results between the two assessments were compared using the Friedman test. RESULTS: There was no difference in mean age between the study group and control group. In the study group, total VVLT score (reflecting short-term memory) was significantly improved from before hearing aid use to 6 months after hearing aid use (P0.05). CONCLUSION: The speech-related cognitive function of individuals with hearing impairment improved after using hearing aids. This finding indicates that hearing aids may induce acclimatization of the central auditory system.