Normal Hearing Patients Research Articles

Attention-deficit/hyperactivity disorder in children with hearing loss.

To evaluate rates of Attention-Deficit/Hyperactivity Disorder (AD/HD) diagnosis among pediatric patients with normal hearing (NH) and hearing loss (HL) with and without comorbidities. Retrospective cohort study of NH and HL patients following chart review of all pediatric patients with a history of tympanostomy tube placement treated at the Cleveland Clinic Foundation between 2019 and 2022. Patient demographic information, hearing status (type of HL, laterality, severity), and comorbidities including prematurity, genetic syndromes, disorders with neurological impairment, and autism spectrum disorder (ASD) were collected. Rate of AD/HD amongst HL and NH cohorts with and without comorbidities were compared using Fisher's exact test. Covariate-adjusted analysis was also completed (sex, current age, age at tube placement, and OSA). The primary outcome of interest was rates of AD/HD among children with NH and HL, and the secondary outcome of interest was the impact of comorbidities on rates of AD/HD diagnosis in these cohorts. Of the 919 screened patients between 2019 and 2022, there were 778 NH patients and 141 HL patients (80 bilateral, 61 unilateral). HL ranged from mild (n=110) to moderate (n=21) to severe/profound (n=9). Overall, the rate of AD/HD was significantly higher in HL children (12.1% HL vs 3.6% NH, p<0.001). Of the 919 patients, 157 had comorbidities. In children without comorbidities, HL children still had significantly higher rates of AD/HD compared to NH children (8.0% vs 1.9%, p=0.02), but there was loss of significance after covariate adjustment (p=0.72). The rate of AD/HD among children with HL (12.1%) is higher than the rate of AD/HD in NH children (3.6%), consistent with previous findings. After excluding patients with comorbidities and adjusting for covariates, there are similar rates of AD/HD between HL and NH patients. Given high rates of comorbidities and AD/HD in HL patients and potential for augmented developmental challenges, clinicians should have a low threshold to refer children with HL for neurocognitive testing, particularly those with any of the comorbidities or covariates described in this study.

Changes in brain gray matter volume in nasopharyngeal carcinoma patients after radiotherapy in long-term follow-up

ObjectivesThe aim of this study was to examine the changes in gray matter in nasopharyngeal carcinoma patients with normal hearing (Group 1) and nasopharyngeal carcinoma patients with hearing loss (Group 2) after radiotherapy using voxel-based morphological analysis and to analyze the relationship with the radiation doses of the temporal lobe. Methods21 patients in Group 1, 14 patients in Group 2, and 21 healthy volunteers were selected. All participants underwent an otologic examination and three-dimensional magnetization preparatory rapid acquisition gradient echo sequence scan. The correlation between the variation of whole brain gray matter volume and the doses of the temporal lobe was analyzed by Data Processing & Analysis for Brain Imaging software. ResultsCompared with the normal control group, the brain areas with reduced gray matter volume in nasopharyngeal carcinoma patients after radiotherapy were mainly in the left posterior cerebellar lobe (T = −8.797), left insular lobe (T = −7.96), and the right insular lobe (T = −6.632). Compared to Group 1, the brain areas of Group 2 patients with reduced gray matter volume were mainly in the left superior temporal gyrus (T = −2.366), left olfactory bulb (T = −2.52), left Rolandic operculum (T = −2.431), and right olfactory bulb (T = −3.100). Compared with Group 1, the brain areas of Group 2 patients with increased gray matter volume were mainly in the left calcarine sulcus (T=3.425) and right calcarine sulcus (T=3.169). There were no correlations between the changes of brain gray matter volume and the radiation doses of the temporal lobe in both Group 1 and Group 2. ConclusionsThe radiotherapy may cause the changes of brain areas associated with cognitive function in nasopharyngeal carcinoma in a long-term follow-up. At the same time, nasopharyngeal carcinoma patients with the radiation-induced hearing loss had abnormal gray matter volumes in the auditory center and other sensory centers. Our findings might provide new understanding into the pathogenesis of radiation-induced brain damage in normal-appearing brain tissue. Yet this exploratory study should be taken with caution.

Management of Vestibular Schwannoma with Normal Hearing

Introduction: This work aimed to study the management of vestibular schwannoma (VS) patients with normal hearing (NH). Methods: A retrospective study was undertaken in a Quaternary referral center for skull base pathologies. Among 4,000 VS patients 162 met our strict audiological criteria for NH. These patients were divided into 2 management groups, wait and scan (W&S) (45/162, 25%) and operated patients (123/162, 75%), and 6 patients were included in both groups. Results: Our management strategy achieved the goals for treatment of VS. First goal, all tumors were completely removed except for 2 intentional residuals. Second goal, facial nerve (FN) function preservation (House Brackmann I, II, and III) was 95.9%. Third goal, possible hearing preservation (HP) attempts occurred in (50/122) (40.9%) with an HP rate in 44% of the patients. Additionally, there were only 2 cases of postoperative complications with no CSF leakage. The prospect of HP in NH patients did not differ with respect to tumor size. However, patients with normal preoperative ABR seemed to have better chances of HP and good FN function and vice versa. HP rate was superior for the MCFA as opposed to the RS + RLA. W&S group demonstrated hearing stability in 88.9% of the patients and FN function stability of HB I in 100% of the patients. Conclusions: Surgical resection is a reasonable and definitive management option for VS with NH. Nevertheless, choosing to manage cases with observation remains an appropriate management option for NH patients. ABR might be considered as an adjuvant tool indicating better prognosis for HP.

Sound localization in patients with bilateral vestibulopathy.

The goal of this study was to evaluate if bilaterally (partially) absent vestibular function during static sound localization testing, would have a negative impact on sound localization skills. Therefore, this study compared horizontal static sound localization skills of normal-hearing patients with bilateral vestibulopathy (BV) and healthy controls. Thirteen normal-hearing patients with BV and thirteen age-matched healthy controls were included. Sound localization skills were tested using seven loudspeakers in a frontal semicircle, ranging from - 90° to + 90°. Sound location accuracy was analyzed using the root-mean-square error (RMSE) and the mean absolute error (MAE). To evaluate the severity of the BV symptoms, the following questionnaires were used: Dizziness Handicap Inventory (DHI), Oscillopsia severity questionnaire (OSQ), 12-item Spatial, Speech, and Qualities Questionnaire (SSQ12), and Health Utilities Index Mark 3 (HUI3). The RMSE and MAE were significantly larger (worse) in the BV group than in the healthy control group, with respective median RMSE of 4.6° and 0°, and a median MAE of 0.7° and 0°. The subjective reporting of speech perception, spatial hearing, and quality of life only demonstrated a moderate correlation between DHI (positive correlation) and HUI total score (negative correlation), and localization scores. Static sound localization skills of patients with BV were only mildly worse compared to healthy controls. However, this difference was very small and therefore most likely due to impaired cognitive function. The vestibular system does not seem to have a modulating role in sound localization during static conditions, and its impact is negligible in contrast to the impact of hearing impairment. Furthermore, the subjective reporting of speech perception, spatial hearing, and quality of life was not strongly correlated with localization scores.

Speech intelligibility deterioration for normal hearing and hearing impaired patients with different types of tinnitus

ObjectivesMany tinnitus subjects report problems with communication, in particular, difficulties with the intelligibility of speech when it is presented in the background of noise. The type of tinnitus (tone-like, noise, etc.), its location and range in the frequency domain, and the type and degree of accompanying hearing loss can affect speech intelligibility in noise in different ways. The main purpose of this study was to determine the effects of tinnitus and degree of hearing loss on the intelligibility of speech when it is presented in a background noise. MethodsA group of 128 patients participated in the study. There were persons with tinnitus and sensorineural hearing loss as well persons with tinnitus without hearing loss. All participants were patients of the Laryngological Centre of Rehabilitation, Medical University in Poznań. The age of patients ranged from 31 to 84 years. An additional group of 10 subjects (24–50 years) with normal hearing and without tinnitus took part in this study as a control group. An initial experiment was concerned with the determination of the tinnitus type. A band of noise of different widths (Q-factor, goodness), with varying centre frequency (f) was used to match the perceived tinnitus type. The Q factor is the ratio of the centre frequency to the noise bandwidth. In the main experiment, the Speech Reception Threshold (SRT) was measured using The Polish Sentence Test (PST). In this test, short sentences were presented in a background of a so-called babble-noise reflecting the averaged spectrum of Polish speech. Resultsamong the different types of signal used by patients to match their tinnitus, the ones most often used were broadband noise in the medium frequency range (BM) and tone-like high-frequency noise (TH). The average Speech Reception Threshold (SRT) for tinnitus patients with normal hearing was 3 dB higher than that for the control group. The highest deterioration in speech intelligibility was observed for broadband tinnitus, located in the mid-frequency band (1.5–5 kHz). ConclusionsTinnitus patients with normal hearing threshold have significantly higher speech reception thresholds (SRT, on average by 3 dB) than normally hearing subjects (control group, without tinnitus), when the speech is presented in a background of babble-noise. Patients with flat audiograms had SRT values on average about 2.5 dB lower than patients with sloping type audiograms (with greater loss at higher frequencies). On average patients in the age group up to 60 years had 4 dB higher SRT values than the control group, and in the older group of patients (above 61 years) - values were 5 dB higher than in the control group. A significant effect of tinnitus located in the medium and high frequency band on the increase of SRT was noted in normally hearing patients and also in patients with mild hearing loss. For higher degrees of hearing loss, the factor that determines the deterioration of speech intelligibility is the hearing loss (moderate and severe), not tinnitus.

Peristimulus Time Responses Predict Adaptation and Spontaneous Firing of Auditory-Nerve Fibers: From Rodents Data to Humans.

Sound-level coding in the auditory nerve is achieved through the progressive recruitment of auditory nerve fibers (ANFs) that differ in threshold of activation and in the stimulus level at which the spike rate saturates. To investigate the functional state of the ANFs, the electrophysiological tests routinely used in clinics only capture the first action potentials firing in synchrony at the onset of the acoustic stimulation. Assessment of other properties (e.g., spontaneous rate and adaptation time constants) requires single-fiber recordings directly from the nerve, which for ethical reasons is not allowed in humans. By combining neuronal activity measurements at the round window and signal-processing algorithms, we constructed a peristimulus time response (PSTR), with a waveform similar to the peristimulus time histograms (PSTHs) derived from single-fiber recordings in young adult female gerbils. Simultaneous recordings of round-window PSTR and single-fiber PSTH provided models to predict the adaptation kinetics and spontaneous rate of the ANFs tuned at the PSTR probe frequency. The predictive model derived from gerbils was then validated in female mice and finally applied to humans by recording PSTRs from the auditory nerve in normal-hearing patients who underwent cerebellopontine angle surgeries. A rapid adaptation time constant of ∼3 ms and a mean spontaneous rate of ∼22 spikes/s in the 4 kHz frequency range were found. This study offers a promising diagnostic tool to map the human auditory nerve, thus opening new avenues to better understanding auditory neuropathies, tinnitus, and hyperacusis.SIGNIFICANCE STATEMENT Neural adaptation in auditory nerve fibers corresponds to the reduction in the neuronal activity to prolonged or repeated sound stimulation. For obvious ethical reasons, single-fiber recordings from the auditory nerve are not feasible in humans, creating a critical gap in extending data obtained using animal models to humans. Using electrocochleography in rodents, we inferred adaptation kinetics and spontaneous discharge rates of the auditory nerve fibers in humans. Routinely used in basic and clinical laboratories, this tool will provide a better understanding of auditory disorders such as neuropathies, tinnitus, and hyperacusis, and will help to improve hearing-aid fittings.

Ten Years Follow Up of Patients with Tinnitus and Normal Hearing.

To describe the natural history of tinnitus in normal hearing patients. This is a prospective longitudinal observational study. Tertiary University Hospital. In 2009 we studied 68 patients with significant tinnitus and normal hearing (Study Group-SG) compared to 46 patients with normal hearing and no tinnitus (Control Group-CG). We have been able to contact and recruit 24 patients from SG (35.3 %) and ten patients from CG) (21.74%) in 2019. Both groups were submitted to conventional audiometry, Distortion Product Otoacoustic Emissions (DPOAE), Tinnitus Handicap Inventory (THI), Visual Analog Scale (VAS) and Beck`S Depression and Anxiety Scales (BDS, BAS). These measures were compared with the same ones performed ten years ago in the same groups of patients. The software SPSS for windows version 21 was used. P values <0.05 were considered significant. Student t test was used to compare SG and CG results in 2019 and to compare 2009 and 2019 outcomes.. Hearing loss, especially in the higher frequencies, were significantly worse in SG compared to GC in 2019. DPOAE were significantly worse in SG and CG in 2019 however CG had more abnormal results than SG. These results suggest that outer hair cells lesions are not the only determinant for tinnitus and hearing loss development. These results suggest that outer hair cells lesions are not the only determinant for tinnitus and hearing loss development.

Effect of Tinnitus in Distortion Products Otoacoustic Emissions (DPOAEs) in Normal Hearing Patients.

Tinnitus is a symptom whose pathophysiology remains still unclear. Its diagnosis and treatment is complicated, due to its subjectivity. The generation of tinnitus is commonly linked with the impaired functioning of the outer hair cells (OHC) inside the cochlea. Distortion product otoacoustic emissions (DPOAEs) are the objective test used to assess their activity. This study investigates the cochlear outer hair cell function in patients with tinnitus and normal hearing using DPOAEs. We performed a prospective study of the cochlear function in normal hearing patients complaining of tinnitus by analysing DPOAEs amplitude and signal/noise (S/N) ratio. We gathered a sample of 21 ears from adults that attended to the ENT Department complaining of tinnitus with normal hearing. We compared their results with a control group of 21 ears, with the same demographic characteristics, presenting normal hearing but without tinnitus in order to exclude the influence of age in DPOAEs results. A decreased mean of S/N levels in DPOAEs was found in tinnitus and normal hearing group comparing with control group, although these differences were not statistically significant (p > 0.05). Based on the results, OHC dysfunction is not necessary to experience tinnitus. The majority of the patients that present OHC dysfunction do not present a tinnitus at the moment. Other mechanisms in auditory pathway may be evaluated in the tinnitus development.

STUDYING THE ACCURACY OF SOUND LOCALIZATION IN NORMAL HEARING SUBJECTS WITH TINNITUS

Tinnitus is a phantom auditory sensation that affects approximately 10- 20 % of the general population. Subjective tinnitus is characterized by an ongoing conscious perception of a sound in the absence of an actual external sound source. Previous studies reported that tinnitus hinder concentration, attention ability and hearing performance, even in normal hearing patients. The sound localization ability is one of the higher functions of the hearing system.Binaural hearing is important for sound Localization as it needed for the perception of interaural intensity differences (IID) and interaural time differences (ITD). As the effect of tinnitus on localization is still controversial. We examine whether tinnitus can affect sound localization ability or not in normal hearing individuals with and without tinnitus using different stimulus at different situation.Aim of the studyThe aim of this study was to test localization accuracy in tinnitus patients with normal hearing.PATIENTS AND METHODS Patients: This study involved two groups of subjects a 20 patient in tinnitus group and 20 patient ingroup who never experienced tinnitus before both groups with normal conventional PTA. The study was conducted in the audiology unit, Otorhinolaryngology department of Alexandria main university hospital.

COVID-19 caused hearing loss.

PurposeThe objective of this cross-sectional study was to determine if there is a potential link between COVID-19 infection and hearing loss.MethodsThe prospective study was conducted in the COVID Hospital Clinical Centre Niš, Serbia. We performed tonal audiometry and used a custom questionnaire and medical histories to determine the incidence of hearing loss in COVID-19 positive patients.ResultsThere were 74 patients with COVID-19 that met the inclusion criteria of this study and they composed our experimental group. Fifty-four (73%) were men and 20 (27%) women. There were 30 (40.5%) patients with hearing loss. Seventeen patients had unilateral and 13 had bilateral hearing loss. Significant differences between hearing loss groups and control group were found across all age groups, but not at all frequencies. No important differences were found when unilateral hearing loss and bilateral hearing loss groups were compared. There were no significant differences in distributions of comorbidities between the patients with hearing loss and normal hearing patients.ConclusionsWe found that 30 (40.5%) of the COVID-19 positive patients had sensorineural type of hearing loss. Across all age groups, there were statistically significant differences in frequencies between the COVID-19 positive patients and the control group. There were no significant differences in distributions of comorbidities between the patients with hearing loss and normal hearing patients. Distribution of unilateral and bilateral hearing loss and audiogram types was also not significantly different between the age groups.

Comparative Performance of Lateral Wall and Perimodiolar Cochlear Implant Arrays.

The physical shape of cochlear implant (CI) arrays may impact hearing outcomes. The goal of this study was to compare post-operative speech and melody perception between patients with lateral wall (LW) and perimodiolar (PM) electrode arrays across a range of lengths and manufacturers. Retrospective chart review. Tertiary Care Hospital. 119 adult patients with post-lingual hearing loss who underwent cochlear implantation. A total of seven different electrodes were evaluated including 5 different LW electrodes (CI422 [Cochlear American], 1J [Advanced Bionics], Medium [Med El], Standard [Med El], Flex28 [Med El]) and 2 PM electrodes (Contour [Cochlear American], MidScala [Advanced Bionics]). Speech perception outcomes (n = 119 patients) were measured by Consonant-Nucleus-Consonant (CNC) scores collected 3, 6, 12 and 24 months after implantation. Melody perception outcomes (n = 35 CI patients and n = 6 normal hearing patients) were measured by Melodic Contour Identification (MCI). CNC scores increased over time after implantation across all array designs. PM designs exhibited higher CNC scores compared to LW electrodes, particularly 6-months after implantation. Pre-operative pure tone averages did not correlate with post-operative CNC scores. PM arrays outperformed LW electrodes in terms of MCI scores. The physical shape of cochlear implant electrode arrays may impact hearing performance. Compared to LW designs, PM arrays appear to offer superior speech perception during the first 6 months after implantation, with performance equalizing between groups by 24 months. Compared to LW designs, PM arrays also appear to afford superior melody perception.

A Questionnaire Survey of Current Rehabilitation Practices for Adults With Normal Hearing Sensitivity Who Experience Auditory Difficulties.

Purpose A questionnaire survey was conducted to collect information from clinical audiologists about rehabilitation options for adult patients who report significant auditory difficulties despite having normal or near-normal hearing sensitivity. This work aimed to provide more information about what audiologists are currently doing in the clinic to manage auditory difficulties in this patient population and their views on the efficacy of recommended rehabilitation methods. Method A questionnaire survey containing multiple-choice and open-ended questions was developed and disseminated online. Invitations to participate were delivered via e-mail listservs and through business cards provided at annual audiology conferences. All responses were anonymous at the time of data collection. Results Responses were collected from 209 participants. The majority of participants reported seeing at least one normal-hearing patient per month who reported significant communication difficulties. However, few respondents indicated that their location had specific protocols for the treatment of these patients. Counseling was reported as the most frequent rehabilitation method, but results revealed that audiologists across various work settings are also successfully starting to fit patients with mild-gain hearing aids. Responses indicated that patient compliance with computer-based auditory training methods was regarded as low, with patients generally preferring device-based rehabilitation options. Conclusions Results from this questionnaire survey strongly suggest that audiologists frequently see normal-hearing patients who report auditory difficulties, but that few clinicians are equipped with established protocols for diagnosis and management. While many feel that mild-gain hearing aids provide considerable benefit for these patients, very little research has been conducted to date to support the use of hearing aids or other rehabilitation options for this unique patient population. This study reveals the critical need for additional research to establish evidence-based practice guidelines that will empower clinicians to provide a high level of clinical care and effective rehabilitation strategies to these patients.

CHARACTERISTICS OF THE BIOELECTRIC ACTIVITY OF THE MASTICATORY MUSCLES IN PATIENTS WITH HEARING DEPRIVATION IN PERMANENT OCCLUSION IN THE PHYSIOLOGICAL STATE

The study of the muscles of the maxillofacial area both in normal and pathological occlusions is the area of great interest, since muscle function is an indicator of complex functional relationships of the dento-mandibular system. Hearing impaired patients have many features related to the functional features of the maxillofacial area due to the slight or complete lack of use of facial muscles during speech or through the use of sign language. Hearing impaired children have 100% of bite pathology.&#x0D; The functional state of chewing and temporal muscles in schoolchildren with hearing loss in constant bite at rest was studied. Twenty-five hearing impaired students with permanent dentistry were studied at Poltava Special Boarding School for Deaf Children, who formed the study group. Among them, there were 13 women (62.5%) and 12 men (37.5%). The mean age was 18.7 ± 1.31 years. The control group used the data of the study of patients with constant physiological bite without hearing disorders, determined by M. I. Dmytrenko. The average age was 21.3 ± 1.25 years.&#x0D; The bioelectric activity of the chewing muscles was examined on an electromyographic complex. The average values of oscillation amplitude (μV) of muscle biopotential on both sides were determined. Muscle biopotentials were recorded for five seconds in a state of physiological calm with closed lips.&#x0D; The results show that all indicators of PD of chewing muscles in a state of physiological rest are almost 2 times higher (p˂0,05) in comparison with those of patients with normal hearing and physiological bite. The work of the temporal muscles in schoolchildren with hearing loss is characterized by symmetry. There is also greater electrical activity of the temporal muscle than the masticatory muscles at rest, unlike normal hearing patients.&#x0D; All patients with hearing impairment had 100% prevalence of dental anomalies. Biopotential of chewing muscle of I class. for angle was 2.7 times higher than in patients with the control group. The biopotential of the temporalis muscle in the ICE was 1.8 times higher (p˂0.05), which indicates a constant tension or insufficient muscle relaxation in patients with ICE. In patients with hearing loss of II class. for angle, the average value of the biopotential of the chewing muscle was 2.3 times higher than in patients in 2 group, the temporal muscle was 1.5 times higher.

The impact of white matter hyperintensities on speech perception.

The presence of white matter hyperintensities (WMHs) can impact on normal brain function by altering normal signal transmission and determining different symptoms. To evaluate the relationship between the presence of brain WMHs and the scores of speech perception test (SPT) in a sample of normal-hearing patients under 70years of age. Prospective study. One hundred eleven patients underwent audiological screening with pure tone audiometry(PTA), tympanometry, speech perception testing (SPT), and brain magnetic resonance imaging (MRI). T2 sequences were analyzed to identify the presence of WMH that, if identified, were scored using theFazekas score. Statistical multiple regressionanalysis was performed to understand the relationship between PTA and SPT score; the Pearson's and Spearman's tests were used to evaluatethe correlation between Fazekas scores and SPT. Chi-square testwas used to analyze the difference between gender. The results of PTA were not predictive of the SPT score. A negative statistically significant correlation (Spearman's, p = 0.0001; Pearson's, p < 0.001) was identified between the Fazekas score and the results of SPT. No statistically significant differences were identified in the correlation ofWMH and SPT between males and females. Multiple WMHs in the brain can worsen word recognition in patients with normal auditory threshold; this may be related to the impact that these lesions have on the memory ability. Spreadof lesions into the brain might reduce the brain capacity to remember words, despite the sound iscorrectly perceived by the ear.

Auditory Agnosia for Environmental Sounds in Alzheimer's Disease: Not Hearing and Not Listening?

Auditory agnosia for environmental sounds (AES) is an example of central auditory dysfunction. It is presumed to be independent of language deficits and in presence of normal hearing. We undertook a detailed neuropsychological assessment including environmental sound naming and recognition in 34 clinically mild Alzheimer's disease (AD) patients and 29 age-matched healthy control subjects. In patients with AD, audiometry was performed to assess the impact on test performance, and in normal controls the Hearing Handicap Inventory for the Elderly - Screening Version to exclude more than mild hearing loss. We adapted a validated environmental sound battery and found near perfect scores in controls. We found that environmental sound agnosia is common in mild AD. We found a statistically significant difference in mean pure tone audiometry in the best ear between patients with and those patients without naming deficits of 11.3 dB (p = 0.010) and of 14.7 dB (p = 0.000) between those with and without recognition deficits. Statistical significance remained after correcting for age, aphasia, Mini-Mental State Examination score, and working memory. Slight and moderate peripheral hearing loss increases the odds ratio of recognition deficits by 13.75 (confidence interval 2.3-81.5) compared to normal hearing patients. We did not find evidence for different forms of AES. This work suggests that an interaction between peripheral hearing loss and AD pathology produces problems with environmental sound recognition. It confirms that the relationship between hearing and dementia is complex but also suggests that interventions to prevent and treat hearing loss could have an effect on AD in its clinical expression.

The ability of gap detection in patients with acoustic neuroma

Objective:We aimed to provide a basis for the clinical study of acoustic neuroma through investigating the ability of temporal gap detection in acoustic neuroma patients and comparing the abilities with those in people with normal and impaired hearing. Method:Twenty-two patients with confirmed acoustic neuroma, 30 normal hearing patients and 16 patients with sensorineural hearing loss were enrolled in this study, and the interval threshold for awareness of each group was tested. Result:The mean temporal gap detection test（TGDT） threshold of the normal hearing group was （3.56±0.82） ms; the sensorineural hearing loss group's was （3.91±1.46） ms; TGDT threshold of healthy side of acoustic neuroma patients was （4.01±1.86） ms; TGDT threshold of the impaired side of acoustic neuroma patients was （9.48±9.46）ms. After statistical analysis, we found that excepting for the test of phonetically balanced maximum （PBmax） and TGDT, other results in the sensorineural hearing loss group and normal hearing group is of no statistical difference. The difference between the affected side of the acoustic neuroma group and the other groups was statistically significant （P<0.05）. There was no linear correlation between the value of TGDT threshold and PBmax （P> 0.05）. TGDT value of normal people has no significant difference among people of different genders and ears of different individuals. Conclusion:The TGDT of the healthy ear of the patients with acoustic neuroma is not affected, and there is no significant change compared with normal people. The TGDT test has a good consistency with the PBmax results. The time interval response ability of the affected ear of the acoustic neuroma is significantly weaker than that of the normal person. The combined test of PBmax and TGDT will contribute to the diagnosis of retrocochlear disease.

Detection of BDNF-Related Proteins in Human Perilymph in Patients With Hearing Loss.

The outcome of cochlear implantation depends on multiple variables including the underlying health of the cochlea. Brain derived neurotrophic factor (BDNF) has been shown to support spiral ganglion neurons and to improve implant function in animal models. Whether endogenous BDNF or BDNF-regulated proteins can be used as biomarkers to predict cochlear health and implant outcome has not been investigated yet. Gene expression of BDNF and downstream signaling molecules were identified in tissue of human cochleae obtained from normal hearing patients (n = 3) during skull base surgeries. Based on the gene expression data, bioinformatic analysis was utilized to predict the regulation of proteins by BDNF. The presence of proteins corresponding to these genes was investigated in perilymph (n = 41) obtained from hearing-impaired patients (n = 38) during cochlear implantation or skull base surgery for removal of vestibular schwannoma by nanoscale liquid chromatography coupled to tandem mass spectrometry (nano LC-MS/MS). Analyzed by mass spectrometry were 41 perilymph samples despite three patients undergoing bilateral cochlear implantation. These particular BDNF regulated proteins were not detectable in any of the perilymph samples. Subsequently, targeted analysis of the perilymph proteome data with Ingenuity Pathway Analysis (IPA) identified further proteins in human perilymph that could be regulated by BDNF. These BDNF regulated proteins were correlated to the presence of residual hearing (RH) prior to implantation and to the performance data with the cochlear implant after 1 year. There was overall a decreased level of expression of BDNF-regulated proteins in profoundly hearing-impaired patients compared to patients with some RH. Phospholipid transfer protein was positively correlated to the preoperative hearing level of the patients. Our data show that combination of gene expression arrays and bioinformatic analysis can aid in the prediction of downstream signaling proteins related to the BDNF pathway. Proteomic analysis of perilymph may help to identify the presence or absence of these molecules in the diseased organ. The impact of such prediction algorithms on diagnosis and treatment needs to be established in further studies.

Comparison of thresholds estimation in adults with conductive hearing loss and normal hearing adults using auditory steady state response evoked by narrow band CE-chirps

Background: Narrowband CE Chirps (NB CE-chirps) were used to provide the characteristics of compensation for the cochlear traveling wave delay and frequency specificity.Aim: The aim was to compare the objective frequency-specific hearing thresholds estimation by the use of NB CE-chirps ASSR and behavioural thresholds in normal hearing subjects and patients with the conductive hearing loss.Subjects and methods: The cases group comprised 35 ears of 25 patients with the conductive hearing loss with varying degree from mild to severe in severity and their age ranging from 15 to 60 years. They were compared with 20 ears of 10 adult control subjects with normal hearing thresholds, whose age ranged from 19 to 42 years. All cases and controls were subjected to pure-tone audiometry (PTA), tympanometry and auditory steady-state response (ASSR), using 4 NB CE-chirp for air conduction (AC) and bone conduction (BC) threshold estimation.Results: AC-ASSR estimated thresholds were statistically significantly higher than AC PTA thresholds at 500, 1000, 2000 and 4000 Hz in both the cases and the control groups. BC ASSR estimated thresholds were statistically significantly lower than BC PTA thresholds only at 500 Hz in the cases and statistically significantly higher than BC PTA thresholds only at 2000 Hz in the controls. There was a statistically significant positive correlation between AC-ASSR and AC PTA, and between ABG-ASSR and ABG PTA in the cases group.Conclusions: Auditory steady-state responses with NB CE-chirps is suitable tool for objective frequency-specific hearing threshold detection, that can be used for estimation of behavioural bone conduction thresholds in adults with conductive hearing loss, with more accuracy in the mid frequencies, and can estimate behavioural air conduction thresholds and air-bone gap more accurately in the higher frequencies 2000, 4000 Hz more than at 500 and 1000 Hz.

Objective assessment of subjective tinnitus through contralateral suppression of otoacoustic emissions by white noise: effects of frequency, gender, tinnitus bilaterality and age.

Accumulating evidence seems to support an association between tinnitus and medial olivocochlear bundle (MOCB) dysfunction. Most studies use patient/control comparisons to support this correlation. The aim of this study was to investigate the hypothesis in a substantially different way and evaluate the roles of gender, age, frequency and tinnitus bilaterality as possible confounding factors. The population consisted of 78 normal hearing patients with chronic tinnitus, 28 normal hearing controls, 19 presbycousic tinnitus patients and 13 presbycousic controls (n = 276 ears). Mean suppression amplitudes of transient evoked otoacoustic emissions (TEOAEs) and distortion product OAEs (DPOAEs) by contralateral white noise (50 dB SPL) were computed. Mean suppression values < 1 dB SPL or < 2 dB SPL were validated as positive test results. Overall suppression (OS) values < 1 dB SPL were qualified as a diagnostic test of moderate positive predictive value for both DPOAEs and TEOAEs, while OS values < 2 dB SPL were found to be of large negative predictive value for DPOAEs and moderate for TEOAEs. Mean suppression values (for all frequencies, OS) are of higher diagnostic value than suppression values corresponding to either lower (1-2 kHz) or higher frequencies (2.8-4 kHz for TEOAEs and 2.8-6 kHz for DPOAEs). After excluding patients with unilateral tinnitus from the analysis, correlations were found to be stronger. Useful correlations were also attributed for all age groups < 61 years. In females, OAE suppression seems to have a stronger positive predictive value, while in males it seems to have a stronger negative predictive value. OAE-based assays of MOCB function as an objective diagnostic tool for subjective tinnitus might deserve further investigation. Tinnitus uni- or bi-laterality is a confounding factor, which probably confirms the observation that defective function of the MOCB usually applies to the contralateral ear as well. Gender is an additional confounding factor, while correlations can be verified for all age groups < 61 years old.

Excitation of the Auditory System as a Result of Non-invasive Extra-Cochlear Stimulation in Normal Subjects and Tinnitus Patients.

One of possible approach that may suppress tinnitus is electrical stimulation of the ear. At first invasive techniques were used (promontory or round window stimulation), nowadays a non-invasive method, namely hydrotransmissive electric stimulation (ES) through external acoustic canal, has been developed. The aim of the study is to investigate the effect of applying ES with positive and negative current polarities on the ears of healthy subjects and on the tinnitus ears of patients with tinnitus. This comparison further clarifies the mechanisms of operation of non-invasive extra-cochlear ear ES. A second aim is to assess the effects of ES on tinnitus in tinnitus patients. The material was composed of two groups: tinnitus group—49 patients suffering from tinnitus, and healthy students group—34 healthy individuals. ES was performed with the use of a custom-made apparatus. The active, silver probe–was immersed inside saline filling external ear canal. The passive electrode was placed on the forehead. Positive and next negative DC stimulation was provided with the use following frequencies: 0.25, 1, 2, 3, 4, 5, 6, 7, 8 kHz. We checked for the presence of the auditory percept (AP) and, if AP was present, the minimum current amplitude necessary to produce AP was measured. In our research both positive and negative polarities were efficient to evoke AP in the participants. This effect, however, was more pronounced for positive polarity in no tinnitus and normal hearing individuals (healthy students group). In the tinnitus group, current intensity needed to evoke AP was higher than in the healthy students group. However, comparing normal hearing vs. hearing loss patients within the tinnitus group, we did not observe the relationship between hearing threshold and current intensity evoking AP. Afterwards, we analyzed the effect of multi-frequency ES on tinnitus. It appeared to be effective in 75% of tinnitus ears (with a high score of disappearance–22%). Our study proved that extracochlear ES with positive and negative current was efficient to stimulate the auditory system. Stimulating tinnitus ears with two polarities we obtained a higher ratio of improvement (75%) comparing to positive stimulations.