Search

Background High-resolution MR imaging enables the visualization of individual nerves in the internal auditory canal (IAC). Cochlear nerve deficiency (CND) is recognized as one of the major causes of sensory neural hearing loss (SNHL), especially in cases of unilateral hearing loss in childhood. Some patients with CND are thought to have accompanying vestibular nerve deficiency (VND). However, there have been few reports focusing on VND and vestibular function in these children. Aims The aim of this study was to evaluate the frequency of VND and vestibular dysfunction in children with unilateral SNHL caused by CND. Material and methods Thirty-eight children with unilateral SNHL, who were diagnosed with CND by 3 T-MRI, were evaluated for VND and underwent caloric testing and cervical vestibular evoked potential (cVEMP). Results Fourteen of 38 patients (37%) had VND, and eleven (29%) of the patients [ten of the patients (71%) with VND] had at least one vestibular dysfunction. The patients with VND had significantly worse hearing and an IAC of smaller diameter than did patients without VND. Conclusions and significance We should pay attention to VND as well as vestibular dysfunction in hearing loss patients with CND.

OBJECTIVE Congenital aural atresia causes severe conductive hearing loss disturbing auditory development. The differences in speech recognition were investigated between bilateral and unilateral aural atresia. DESIGN The maximum speech recognition scores (SRSs) were compared between patients with bilateral and unilateral aural atresia. In patients with unilateral aural atresia, the maximum SRSs were compared between the atretic and unaffected ears. Furthermore, the correct response rates for test material monosyllables were compared with those of patients with sensorineural hearing loss (SNHL), which had been previously obtained. STUDY SAMPLE Twenty-four patients with aural atresia (8 bilateral, and 16 unilateral) participated. RESULTS The maximum SRS in unilateral atretic ears (median: 72%) was significantly lower than that in unaffected ears (median: 89%) (p

Objective: This study explored cortical auditory evoked potential (CAEPs) elicited by speech sounds in children with unilateral congenital aural atresia (CAA). Design: Twelve children (8 males) age...

To evaluate the overall functional and audiological benefits in unilateral hearing loss, as well as performance improvements with Cochlear™ Baha® Attract System with Baha® 5 sound processor.We performed a prospective study. Fourteen consecutive adult patients with unilateral hearing loss who were audiologically eligible for Baha® Attract were included in this study. All patients were followed-up, and a series of tests were performed in the sound field before surgery, one, two, three, and 6 months after surgery.Patients were categorized based on their hearing impairment type and severity. Ten patients had conductive hearing loss (CHL), or mixed hearing loss (MHL), and four patients had sensorineural hearing loss (SNHL). The hearing threshold in the sound field aided with Baha® Attract was similar to the preoperative bone conduction hearing threshold of the better ear. The results of the speech audiometry improved post-operatively, but they did not match that of the better ear before surgery. The overall score of the hearing-in-noise test was gradually improved from one month to 6 months after surgery. The results of the sound localization test for SNHL patients were not as good as those for CHL or MHL. All the questionnaires demonstrated additional benefits that implied performance improvements.The Baha® Attract provides enough auditory benefits and performance improvements for hearing impaired patients, though there are different benefits according to the type of hearing loss. Clinicians need to counsel the unilateral hearing loss patients for Baha® Attract System carefully, according to their type of hearing loss.

According to population-based prevalence data, more than 40% of children diagnosed with a hearing impairment have a mild to moderate bilateral or unilateral hearing loss. Prior to newborn hearing s...

Objective: To examine cortical auditory evoked potentials (CAEPs) and behavioural measures of spatial speech in noise recognition, sound localization and self-reported perception of hearing...

Subjects with unilateral hearing loss (UHL) report difficulties in speech understanding in noise. Speech-evoked auditory brainstem response (S-ABR) provides cues for temporal and spectral encoding of speech in the brainstem. S-ABR recording in noise increases its sensitivity in evaluating the auditory processing and related disorders.Study speech encoding at the level of brainstem when the auditory system relies on one ear and to study the effect of noise on this encoding.This study included two groups: control group consisted of 15 adults with normal hearing sensitivity and study group consisted of 30 adults with UHL. The study group was further subdivided into two subgroups: study subgroup A (SG A) consisted of 15 adults with right functioning ears and study subgroup B (SG B) consisted of 15 adults with left functioning ears. S-ABR in quiet and with ipsilateral noise was recorded in both the groups using complex ABR advanced auditory research module.In UHL, there was a statistically significant delay in the S-ABR onset and offset in noise compared to quiet. Moreover, quiet-noise (+5 SNR) correlation was significantly low compared to NH. Furthermore, pitch representation (F0 amplitude) was significantly degraded with noise. In addition, there was a statistically significant noise-induced phase shift in the transition region of speech syllable in these subjects.In monaural processing, pitch representation (F0 amplitude) and cross-phaseogram were the main affected domains. Speech phonemes of transient origin can be confused in subjects with UHL.

The purpose of this study was to describe the clinical characteristics of children with unilateral hearing loss (UHL), examine deterioration in hearing, and explore amplification decisions.Population-based data were collected prospectively from time of diagnosis. Serial audiograms and amplification details were retrospectively extracted from clinical charts to document the trajectory and management of hearing loss.The study included all children identified with UHL in one region of Canada over a 13-year period (2003-2015) after implementation of universal newborn hearing screening.Of 537 children with permanent hearing loss, 20.1% (108) presented with UHL at diagnosis. They were identified at a median age of 13.9 months (IQR: 2.8, 49.0). Children with congenital loss were identified at 2.8 months (IQR: 2.0, 3.6) and made up 47.2% (n = 51), reflecting that a substantial portion had late-onset, acquired or late-identified loss. A total of 42.4% (n = 39) showed deterioration in hearing, including 16 (17.4%) who developed bilateral loss. By study end, 73.1% (79/108) of children had received amplification recommendations.Up to 20% of children with permanent HL are first diagnosed with UHL. About 40% are at risk for deterioration in hearing either in the impaired ear and/or in the normal hearing ear.

Cochlear implantation is becoming widely used outside the tertiary research centers for treatment of unilateral deafness (UD). No consensus exists, however, on the most suitable assessment/evaluation protocols for this group of adult patients. This paper aims to review the assessment and evaluation protocols used by various research groups and to propose a protocol for the use in the clinical setting.The PubMed, Embase, and Cochrane Library databases were searched with the keywords 'cochlear', 'implant', 'single-sided', 'deafness', 'adults', 'unilateral', and 'deafness'. The words were either used individually, combined in pairs, or in groups of 5. All articles reporting on prospective studies, retrospective studies, or case studies were included.Sixteen published studies met the inclusion criteria. Measures of hearing performance, tinnitus, subjective quality of hearing, and quality of life varied greatly among studies.Adaptive speech in noise testing, localization, tinnitus measurement questionnaires, and self-rated hearing improvement are widely used among the research groups. These tools in conjunction assess and evaluate the main issues associated with UD.The test battery most commonly used to assess and evaluate adult cochlea implant users with UD consists of (a) a subjective self-rating of hearing performance, (b) localization testing, and

To examine the auditory benefit of cochlear implants (CI) in patients with single-sided deafness (SSD).Twenty patients with a normal pure tone audiogram (n = 8) or moderate hearing loss (n = 12) in one ear and a CI system MED-EL SONATA/CONCERTO + OPUS2 (n = 12), COCHLEAR CI24RE(ST) + CP810 (n = 7) and Advanced Bionics HiRes90 K + Harmony (n = 1) in the contralateral ear and with at least 6 months of CI experience were tested with respect to directional hearing, speech perception in noise, binaural loudness matching, and binaural pitch matching. Twenty-six normal hearing controls were included for normative reference.Addition of the CI significantly improves directional hearing (percentage of correct source identifications improved from 14.9 to 15.6%, root mean square error decreased from 125 to 93°) and improves speech perception in noise (speech perception threshold median improved from -2.3 to -6.0 dB signal to noise ratio, equivalent to a binaural intelligibility level difference = 3.7 dB). Alternate binaural loudness balancing showed that matching takes place at levels between 48 and 55 dB HL (group averages). In the pitch matching experiment, the standard deviation of the relative interaural frequency difference at 500, 1000, and 2000 Hz was 24.5, 22.8, and 24.0%, respectively (compared to 11.7, 14.4, and 12.3% in the control group).In SSD, cochlear implantation considerably improves audiological performance in terms of directional hearing, binaural signal equivalence, and speech perception.

Unilateral deafness and highly asymmetric hearing loss can impair listening abilities in everyday situations, create substantial audiological handicap, and reduce overall quality of life. Preliminary evidence suggests that cochlear implantation may be effective in reversing some of these detrimental effects. Patient-level data from existing studies were re-analysed to explore potential factors that may be predictive of improved speech perception scores following implantation.Logistic regression modelling examined whether improved speech perception following implantation under various listening conditions was related to the duration of deafness of the severe-to-profoundly deaf ear and/or the level of hearing in the better ear.Patients with a shorter duration of deafness were more likely to improve in listening conditions that created a less favourable SNR at the implanted ear than the non-implanted ear. Those with more residual hearing in the better ear were more likely to improve in the listening condition that created a less favourable SNR at that ear.The analysis suggests that characteristics of both ears may be relevant when seeking to identify those candidates who are likely to obtain benefit to speech perception following cochlear implantation.

To determine the use of a hearing aid at six months post-fitting and to evaluate the predictors of its ongoing use in Korean adults with unilateral hearing impairment (HI).Retrospective study at a secondary referral hospital over a 15-year period.This study analysed 119 adults with unilateral HI who had been recommended for hearing amplification (55 men and 64 women, mean age, 58.0 ± 11.7 years). Six months after the fitting, all of the participants were surveyed regarding subsequent decisions and actions about obtaining hearing aids.General uptake rate for a hearing aid was 68.1% (58.0% of participants surveyed were successful users, and 10.1% were intermittent users). The most significant parameter associated with hearing-aid use was social and/or work activities (R(2) = 0.457), and the significant predictors for successful hearing-aid use were social and/or work activities and method of signal processing (discriminatory power = 56.3%).Six months post-fitting, 68.1% of Korean adults with unilateral HI who had agreed to try a hearing aid continued to use it regularly. The predictors for hearing-aid use six months post-fitting included social and/or work activities and digital signal processing.

Up to 40% of children with hearing loss present with other developmental disabilities. The purpose of this study was to document the prevalence of autism spectrum disorders (ASD) in children with permanent hearing loss, to describe the audiologic characteristics, and to examine clinical management.Prospective data related to clinical characteristics of children identified with hearing loss and ASD were examined. A retrospective chart review was also conducted to explore clinical management and uptake of amplification.The study included all children in one Canadian region identified with permanent hearing loss and followed from 2002-2010.Of a total of 785 children with permanent hearing loss, 2.2% (n = 17) also received a diagnosis of ASD. The 13 boys and 4 girls presented with a range of audiologic profiles from unilateral to profound bilateral hearing loss. Four of five children with unilateral hearing loss experienced progression to bilateral loss. Amplification was recommended for all but one child and 9 of 16 children continued to use their hearing devices.The higher prevalence rate of ASD in this clinical population is consistent with previous reports. Our findings suggest that some children with autism can derive benefits from the use of amplification.

To compare the effectiveness of two types of treatment for unilateral hearing loss (UHL), bone-anchored hearing instruments (BAHI) and a dental device (SoundBite).Either BAHI or SoundBite were worn for 30 days, and then the devices were swapped and the second device was worn for 30 days. Measures included unaided and aided sound-field thresholds, sound localization, and perception of speech in babble. The APHAB questionnaire was administered for each trial period.Nine adult BAHI wearers with UHL.Mid-frequency aided thresholds were lower for SoundBite than for BAHI. Both devices gave benefits for localization after 30 days, but there was no difference between devices. Speech perception was better for both devices than for unaided listening when the target speech came from the poorer hearing side or in front, and the interfering babble came from the better-hearing side. There was no consistent difference between devices. APHAB scores were better for SoundBite than for BAHI.Speech perception and sound localization were similar for the two types of device, but the SoundBite led to lower aided thresholds and better APHAB scores than the BAHI.

To evaluate the prevalence of labyrinthine ossification, and especially cochlear ossification, in a cohort of patients with unilateral sudden deafness or severe sensorineural hearing loss.Retrospective data collection.Sixty-four consecutive patients with unilateral sudden deafness or severe sensorineural hearing loss and either high-resolution CT (HRCT) of the temporal bone (isotropic spatial resolution ≤ 0.8 mm; n = 18) or high resolution CISS MRI (isotropic spatial resolution ≤ 1 mm; n = 55) were included. Nine patients underwent both imaging modalities. A standardized reading regarding labyrinthine ossifications was performed by an experienced head and neck radiologist blinded to clinical symptoms.Radiologic signs of cochlear ossification were present in 14 patients (12 CT and 2 MRI). Eight patients showed unilateral and six patients bilateral signs of cochlear ossification. In all except one of the unilateral cases, the deafened ear was affected.Signs of cochlear ossification were found in an unexpectedly high rate (14/64, 22%) of patients with acute deafness. The data suggest HRCT of the temporal bone to be more sensitive to detect labyrinthine ossification than MRI. HRCT of the temporal bone should therefore be considered in patients with impaired recovery of acute deafness to exclude cochlear ossification; if present, and, in cases of early signs, the patient should be evaluated further to facilitate early cochlear implantation before progression impedes electrode insertion, reflecting latest developments considering cochlea implants for single-sided deafness to be effective.

This case is of a 70-year-old man with single-sided deafness (SSD) in the right ear since childhood, who developed a sudden severe hearing loss in the left ear at the age of 63. Eventually, after he received cochlear implants in both ears, he started to present behavioural auditory processing skills associated with binaural hearing, such as improved ability to understand speech in the presence of background noise, and sound localization. Outcomes were measured using cortical auditory evoked potentials, speech perception in noise, sound localization tests, and a self-rating questionnaire. The results suggest that even after more than 50 years of unilateral deafness it was possible to develop binaural interaction and sound localization as a result of electric auditory stimulation.

We herein report a unique case of a lateral pontine demyelinating lesion presenting with unilateral sensorineural hearing loss and paradoxical ipsilateral hyperacusis. The association of unilateral hearing loss and ipsilateral hyperacusis is a rare manifestation of a central nervous system lesion. The paradoxical combination of these symptoms strongly suggests pontine dysfunction and prompts urgent neurological evaluation.

Conclusions The majority of the patients with unilateral auditory neuropathy spectrum disorder (UANSD) were pediatric and mostly showed a great degree of hearing loss when diagnosed. Abnormal auditory brainstem response (ABR) and preserved otoacoustic emissions (OAEs) and/or cochlear microphonics (CM) were important features to differentiate it from common sensorineural deafness and central nerve hearing loss. Objective To identify the clinical characteristics of patients with UANSD. Methods This was a retrospective study involving 14 patients diagnosed as having UANSD between 2004 and 2010 in the Chinese PLA Hospital. Results In all, 50% of the cases were males (1:1 sex ratio) and the average age of onset was 4.1 years. Of the 14 affected ears with UANSD in these cases, 6 were left-sided, while 8 were right-sided. Of the 14 contralateral ears, 4 presented with sensorineural hearing loss, while the other 10 showed normal hearing. The degree of hearing loss in the 14 affected ears varied, including moderate in 1, moderately severe in 4, severe in 5, and profound in 4. ABRs were absent in the 14 affected ears, while the OAEs, and/or CM were present.

Severe tinnitus can seriously impair patients in their activities in daily life and reduce their quality of life. The aims of this prospective clinical study were to assess the long-term effects of cochlear implantation (CI) on tinnitus in patients with single-sided deafness and ipsilateral incapacitating tinnitus, and to investigate whether CI could treat various types of tinnitus.Twenty-six subjects with unilateral severe-to-profound sensorineural hearing loss received a CI. Patients suffered from severe tinnitus greater than 6/10 on a visual analogue scale (VAS) due to unilateral deafness. Assessment consisted of a tinnitus analysis including determination of tinnitus type, frequency, and loudness. A tinnitus questionnaire (TQ) measured tinnitus distress. VAS and TQ were administered pre-implantation and post-implantation.All 26 patients reported a subjective benefit from CI. Tinnitus loudness reduced significantly after CI from 8.6 to 2.2 on the VAS (scale: 0-10). The TQ total score decreased significantly and the mean tinnitus degree decreased from severe to mild. No differences were observed between patients with pure-tone tinnitus, narrow band noise tinnitus, or polyphonic tinnitus. The degree of tinnitus loudness reduction remained stable after CI.CI can successfully be used as treatment of severe tinnitus in patients with single-sided deafness and is equally effective for pure tone, narrow band noise, and polyphonic tinnitus. Long-term results show that implantation provides durable tinnitus relief in these patients. These results support the hypothesis that physiopathological mechanisms after peripheral deafferentation are reversible when hearing is restored. Single-sided deafness accompanied by severe tinnitus is a new indication for CI.

We question the justification for the cost of a surgically implanted device for the restoration of limited circumstances of audible communication, although we understand that the decision is taken depending on the social relevance of communication or personal criteria.The purpose of this study was to evaluate the effect of the BAHA simulator (BAHAS) system in subjects with acquired unilateral sensorineural hearing loss. In particular we tested the changes of speech reception threshold (SRT) in relation to different speech source positions, with a background of diffuse noise.The primary message consisting of lists of Italian sentences was delivered from a loudspeaker placed at horizontal azimuths of 0°, 90°, 180° and 270°; the interference consisted of uncorrelated speech-shaped noise simultaneously delivered by four loudspeakers at a fixed intensity. The speech recognition tests were administered to 11 patients with BAHAS either on or off; hence each patient underwent 8 acoustic conditions (4 primary message directions × 2 BAHAS conditions). The SRT (50% correct responses) was measured by a simple 2 dB step adaptive procedure. Ten normal-hearing subjects served as the control group.Our data demonstrated that even for the acoustic condition where BAHAS should be more useful (i.e. lateral speech toward the impaired side), it was definitely ineffective in the study conditions.

Congenital cytomegalovirus (CMV) infection is asymptomatic in 90% of infected newborns but approximately 10-20% of these infants are at risk of developing sequelae later, mostly hearing deficit. The aims of the study were to investigate the prevalence of congenital CMV infection in a Swedish population of newborns and investigate the relative risk of hearing deficit in newborns with congenital CMV infection. The dried blood spot (DBS) samples of 6060 newborns in southern Stockholm during 12 months (October 2003-June 2004; August 2004-October 2004) were analysed for CMV DNA by TaqMan based real-time PCR. Hearing deficit was assessed by otoacoustic emission (OAE) within a newborn screening programme. 12 infants out of 6060 or 0.2% (95% CI 0.1-0.3%) had congenital CMV infection. One boy among the 12 infected infants had unilateral hearing loss, indicating that the risk of hearing loss is greatly increased (about 20 times) in CMV infected infants. No child developed ocular complications such as chorioretinopathy during 3 y of follow-up. Congenital CMV has an impact on child health but can easily be overlooked due to lack of signs in the neonatal period. Surveillance for congenital CMV is important in addition to programmes for prevention and treatment.

A new questionnaire, developed to investigate self-reported hearing difficulties in unilateral deafness, was completed by 221 post-surgical vestibular schwannoma patients. Results were compared to a group of 51 normal hearers and 12 patients with severe unilateral deafness from other causes. The vestibular schwannoma patients rated their post surgical hearing as profoundly deaf in the operated ear, and worse than pre-surgical in the other. Factor analysis of the results revealed a general hearing factor and five factors, indirect listening, direct listening, face-to-face listening, noise and distance, and localization, representing performance in specific listening situations. Two factors, direct listening and face-to-face listening have not been commented upon previously in the literature. No differences were found between the hearing-impaired groups on any of the factors. Both groups gave ratings significantly worse than the normal hearers on all factors, and rated themselves worst on indirect listening, in which speech comes from the impaired side. It was concluded that severe unilateral deafness is a significant disability, requiring more attention in clinical practice, particularly with pre-surgical vestibular schwannoma patients.

A male with unilateral deafness in the right ear since 8 years of age developed a sudden hearing loss in the left ear at age 63. A hearing aid was fitted in the left ear with limited benefit. The right ear received a cochlear implant (CI) 20 months later. Cortical auditory evoked potentials (CAEPs) and speech recognition scores (SRS) were measured in free-field three, six and nine months after implantation with the hearing aid alone, CI alone and bimodal condition (hearing aid and CI together). Three months after implantation the cortical responses for the two ears were similar, despite more than 50 years of unilateral auditory deprivation. CAEPs measured over time show evidence of binaural interaction and improvements in SRS. Copyright © 2007 John Wiley & Sons, Ltd.

Previously, unilateral hearing impairment (UHI) has been considered of little consequence. However, a recent meta-analysis of children with UHI displayed educational and behavioural problems and possible delays of speech and language development. Further, patients with UHI consequently report hearing difficulties. Our study investigated hearing function, possible inner ear protection, and self-assessed hearing problems in 57 subjects aged between 3–80 years with single-sided congenital ear malformations and conductive UHI. Pure-tone thresholds and speech recognition (quiet, noise) were measured, and all patients completed a self-assessment questionnaire. Pure-tone thresholds corresponding to sensorineural function did not significantly differ between the normal (air conduction) and affected ear (bone conduction). However, speech recognition in both quiet and in noise was normal on the non-affected side but significantly worse on the malformed side. A moderate to high degree of self-assessed hearing proble...

An epidemiological study was carried out in the year 2000 and sought to measure the occurrences of middle ear disease and hearing loss within school aged (4 years to 12 years) Aboriginal children. A number of the local schools and preschools in Coraki and Lismore with a high percentage of Aboriginal students were selected in an effort to identify service gaps regarding essential hearing screenings and assessments. A total of 185 (370 ears) Aboriginal children aged 4 years to 12 years were examined from four schools and three preschools. This examination included otoscopy, tympanometry and audiometry. Data were collected as each child was tested and this was then entered into a computer database on returning to the work place. Results indicated that 61.08% of these children had middle ear problems of some type. Unilateral hearing loss of 30 dB or greater was found in 10.80% of children, bilateral hearing loss of 30 dB and greater was found in 22.16%, and perforation of tympanic membranes in 3.24%. Suggestions are made in relation to the need for ongoing training of Aboriginal Community Audiometrists to provide community, school and preschool screening programs together with health related promotional activities to minimise the occurrences of ear infections.

The purpose of this study is to establish a model of universal newborn hearing screening in Taiwan. The project of screening is a large-scale implenlentation of the transient evoked otoacoustic emissions. The screening test was carried out on newborns 48 hours after birth, just prior to hospital discharge. The project extended from November 1998 to December 2001 at Mackay Memorial Hospital, Taipei. A total of 11 291 newborns were screened. Among them, 10 556 babies (93.5%) passed the test bilaterally, but 735 babies (6.5%) failed it. For those who failed in screening it was arranged to have OAE or ABR testing for further assessment. The results show that 18 babies were diagnosed to have bilateral hearing loss and 41 unilateral hearing loss. The prevalence of congenital bilateral hearing loss is about 0.16% and that of unilateral hearing loss is approximately 0.36%. All the babies identified with bilateral hearing loss were referred to the Children's Hearing Foundation for hearing rehabilitation.

We have carried out a study to ascertain the prevalence of permanent unilateral hearing loss in Warrington, and to establish the usefulness of audiological assessment and computed tomography (CT) of the temporal bone in the evaluation and management of the children. Full ascertainment of 37 children has been undertaken. The prevalence of permanent unilateral hearing loss equal to or greater than 40 dB HL was 115 per 100,000. Nineteen further children presented consecutively to the Joint Community Audiology and Ear, Nose and Throat Services during the course of the study. Audiological assessment was carried out in 55 children. Thirty‐nine CT scans were undertaken. CT scans were abnormal in 11 children (27%). Dilatation of the vestibular aqueduct was present in two children. In a third child there was aplasia of the cochlea, dysplasia of the semi‐circular canals and a small internal auditory canal. In a fourth child there was a narrow internal auditory canal on the side of the unilateral sensorineural heari...

The objective of this study was to examine the outcome of unilateral stapes surgery in one patient group with bilateral hearing loss and one group with unilateral hearing loss. The patients' own estimations of improvement in hearing ability and the occurrence of other ear-related symptoms were examined retrospectively and in a follow-up study. Ninety-five of 123 patients operated for otosclerosis in only one ear between 1987 and 1992 responded to a follow-up examination. Observed audiometric findings and changes thereof, along with the patients' own estimations of their hearing handicap pre- and postoperatively, and the occurrence of other ear-related symptoms were studied. Despite good surgical results (closure of air-bone gap within 20 dB in 94%), 33% of the patients had severe hearing disabilities postoperatively, and many of these patients needed further amplification with a hearing aid. Mild dizziness occurred in 33% of the patients postoperatively and did not decrease over time. Discomfort in the operated ear due to strong sounds was reported in 20%. Change in sound quality occurred in 80% of the operated ears, but tended to disappear over time. From the results of this study it may be concluded that surgery in one ear only, leaving the other ear with poor hearing, is not an optimal hearing rehabilitation of patients with otosclerosis. It is important endevour to achieve bilateral hearing in order to give the patient good social hearing. Postoperative dizziness and unpleasant hearing quality do occur frequently, and the patients need to be informed about these problems preoperatively.

We report on a case of reversible pontine deafness caused by multiple sclerotic lesions in the pons. and describe six experiments in humans. in whom we recorded transient otoacoustic emissions and distortion products. Our findings indicate an inhibitory effect of efferent innervation on the motility of outer hair cells in humans. Otoacoustic emissions increased in patients with unilateral deafness after the central part of the efferent pathway was destroyed (pontine deafness). Otoacoustic emissions also increased in patients with myasthenia gravis after the administration of an acetylcholinesterase inhibitor. General myotonia (Batten -Curschmann-Steinert Syndrome) resulted in mild sensorineural hearing loss, and in the absence of contralateral inhibition of otoacoustic emissions. Otoacoustic emissions dccrcascd gradually under general anaesthesia with muscle relaxation. Contralateral acoustic stimulation was seen during anaesthesia with muscle relaxation.

We mailed questionnaires to 98 university hospitals and 939 hospitals with 200 beds or more throughout Japan asking for information on patients treated for sensorineural hearing loss between January 1 and December 31, 1987. The number of patients treated for sensorineural hearing loss in 1987 in Japan was estimated 13,900-19,600, ii) idiopathic bilateral progressive sensorineural hearing loss 13,900-19,600, ii) idiopathic bilateral progressive sensorineural hearing loss in 800-2,000, iii) perilymphatic fistula in 200-310, iv) mumps deafness in 200-400, and v) unilateral profound deafness in 2,000-3,000. Sex ratio (men over women) was 0.9 in sudden deafness and mumps deafness, 1.1 in idiopathic bilateral progressive sensorineural hearing loss and 1.5 in perilymphatic fistula. Patients were distributed with a definite peak from 50 to 59 years old in sudden deafness, from 30 to 39 years old in perilymphatic fistula, and two apparent peaks in teenagers and those aged 60-69 years in idiopathic bilateral progressive sensorineural hearing loss.

Electrical stimulation through a round window electrode has been evaluated in 9 patients with unilateral deafness and severe tinnitus. Three subjects were permanently implanted with positive long lasting results. Analysis of the threshold of sound perception, tinnitus suppression and auditory discomfort levels as a function of current frequency revealed the advantage of low frequency stimulation. In 2 patients the loudness of electrically evoked sound perception was balanced against tones in the hearing ear. Our results can be interpreted as indicating that processes other than auditory masking are responsible for electrical tinnitus suppression.

The purpose of the investigation was to study the symptoms that may provide clues to the early diagnosis of vestibular schwannoma (VS). The symptoms associated with VS in 41 patients were compared with the tumour locations detected by magnetic resonance imaging (MRI). There were 9 (22%) mainly intracanalicular and 32 (78%) mainly extracanalicular tumours. MRI visualized the enhancement of the intracanalicular nerve in 27 of 32 extracanalicular schwannomas. Hearing impairment was found as an initial symptom equally frequently in patients with intra- or extracanalicular VS. Tinnitus was reported as the first symptom more often in patients with extracanalicular VS and dizziness more often in patients with intracanalicular tumours. At the time of diagnosis, unilateral hearing loss was present in 98% of patients, independent of tumour location. Likewise, dizziness was found equally frequently in both patient groups. Instead, tinnitus was found almost significantly more frequently in patients with intracanalicular VS (p = 0.07). Although statistically insignificantly so, neurological symptoms were more common in patients with extracanalicular VS (p = 0.45).

ABR recordings were made on 31 normal-hearing subjects and 253 patients with sensorineural hearing loss (86 patients with unilateral hearing loss, 61 patients with asymmetrical hearing loss, 34 patients with symmetrical hearing loss, 55 patients with noise-induced hearing loss and 17 patients in the late chronic stage of Menière's disease). In the patient group with unilateral hearing loss, the mean interpeak interval (IPI) I-V was significantly shorter than in normal-hearing subjects. The interaural IPI differences provide a sharp criterion for early detection of acoustic neuroma. The calculation of the 95%-limits (means + 1.96 SD) showed that in patients with normal hearing or with unilateral or symmetrical hearing loss an interaural difference in the IPII-V greater than 0.2 ms has to be considered as an indication of a neuroma or any other brainstem abnormality. In patients with asymmetrical or with noise-induced hearing loss, the limit is 0.3 ms. In contrast to the frequently recommended interaural wave V latency difference criterion, the interaural IPI difference criterion requires no correction for audiogram differences.

Because hearing disorders often go unrecognized, afflicted students may be misdiagnosed as learning disabled and eventually many exhibit behavioral problems. Alert educators have a role to play in identifying auditory problems before they seriously disrupt a child's performance. White describes some of the most common types of hearing disorders — high frequency hearing loss, unilateral hearing loss, fluctuating conductive hearing loss, and auditory processing deficiency — and the symptoms that give clues to their presence. She suggests that it may be important to all children to reduce the overall level of classroom noise.

A group of children suffering from unilateral hearing loss (UHL) were evaluated. Serological tests were performed and vaccination against mumps was offered if negative. In 43.6% of the cases mumps was the plausible cause but a further 33.3% had positive serological tests for mumps without having had the clinical disease. Due to the long delay in the diagnosis of UHL, the question of mumps as major causative agent can be solved only when the results from prophylactic vaccination become apparent in the future. Thirty children aged 10-16 years underwent further audiological examination in order to detect any difference between right and left UHL. The results of word discrimination scores (PB lists) show the well known superiority of binaural v. monaural hearing but was too crude for a detailed analysis of ear difference. An interrupted speech test in background noise shows, however, that right ear impaired children perform significantly poorer than the left ear impaired and are at risk whenever reverberation conditions are poor.

Brainstem evoked response audiometry has been performed in 164 patients complaining of tinnitus, unilateral or bilateral. The latency of every wave and the latency between the peak of every wave have been compared with those obtained in a normal population (n = 57). The latency of the first wave is increased significantly at the same side of the tinnitus. But I-V latency is shorter at the side of the tinnitus. When this increase is absent, the I-V latency is prolonged the side of the tinnitus. It is possible to differentiate between tinnitus of peripheral origin and that of central origin, although the existence of unilateral deafness is constant. The same results have been obtained in the deaf patients with bilateral symmetric deafness, in accordance with Maurizi et al., 1985.

(1) It is well known that unilaterally hearing-impaired patients in noisy surroundings reveal particular communication disabilities, which can to a large extent be eliminated by utilizing a classical CROS arrangement, i.e. contralaterlal routing of signals from the poorer ear to the better. During the period 1972–74 this fact has been experienced empirically by 203 adult patients at the Department of Audiology, Sodersjukhuset. (2) 30 patients have been further investigated in noisy surroundings as to their discrimination abilities, using P.B. lists and various azimuth positions under “anechoic” conditions in a specially arranged set-up. (3) It has been clinically proven that under the everyday acoustic conditions that have been used, i.e. S/N = + 5 dB and with the sound source at the poorer ear, the discrimination loss compared with the sound source at the better ear is ca 40 %, a loss which is almost eliminated when a classical CROS arrangement is employed. The reduction in listening ability in the unaid...

Generally, a bilateral symmetry of the acoustic stapedius reflex is assumed. But a homolaterally higher sensitivity has been described. We examined 71 patients with complete unilateral deafness. With a TDH 39 headphone, stimuli of intensities up to 133 dB were conveyed to the deaf ear. A fairly accurate estimate of the normal homolateral threshold is obtained by correcting for the cross-hearing loss and by mathematical consideration of the relative probabilities of the positive and negative cases. Methodology-specific influences are discussed and a correction made for them. The homolateral reflex threshold is 9–14 dB lower than the contralateral reflex threshold.ResumeOn suppose souvent qu'il existe une symetrie bilaterale du reflexe stapedien acoustique; cependant, une plus grande sensibilite homolaterale a ete decrite par Moller et par Borg. Nous avons examine 71 patients ayant une cophose unilaterale. Le stimulus (intensites allant jusqu'a 133 dB) fut donne a l'oreille sourde a l'aide d'un casque d'eco...

Thirty children (age 10 16 years) suffering from unilateral hearing loss (UHL) were matched with a control group and examined by a battery of psychological tests (verbal and non-verbal subtests) in order to investigate a possible right or left ear difference on cognitive functions. The results confirm that right ear impaired children perform significantly poorer than their left ear impaired counterparts especially in verbal subtests that are sensitive to minor input/processing damages. The data obtained suggest that right ear impaired children are at risk in the educational system.

The recent audiological literature has put forward the hypothesis that children with unilateral hearing loss (UHL) show delays in educational achievement and academic progress and some behavioural difficulties. This motivated us to investigate the long-term effects of monaural auditory deprivation in a group of adults who had suffered from UHL since childhood. A group of subjects, ranging in age from 30 to 55 years, suffering from sensorineural UHL since early childhood, has been examined for psychosocial and psychoacoustical effects and statistically compared with a control group matched for age and sex. We prepared a questionnaire directed to provide some objective and subjective indices of psychosocial disability and handicap. Some questions were directed towards specific aspects of auditory function; others assessed the degree of education and the type of working performed. The results of the investigation confirmed the superiority of binaural v. monaural hearing. This was clearly demonstrated in psycho-acoustical performance in sound localisation, speech recognition in noise, together with the appreciation of music. On the other hand, the parameters concerned with educational, social and employment achievement did not support the existence of any significant difference between binaurally and monaurally hearing subjects. The data obtained in the present study thus do not support the existence of non-auditory, long-term effects of monaural hearing loss.

The clinical findings in 125 patients with surgically confirmed acoustic neuromas are presented, with special regard to the involvement of the intermedius nerve in the diagnosis. In assessing the function of the intermedius nerve the examination of the nasolacrimal reflex and the sensation of taste on the anterior two-thirds of the tongue are used. The methods of investigation are described in detail. The material consisted of 20 medium-sized and 105 large tumours; no intracanalicular tumor was found. Hearing loss was the initial symptom in 85% of the patients, 10% had tinitus and 4% vertigo as the first symptom. Apart from the VIII cranial nerve symptoms, a defective nasolacrimal reflex was the most significant evidence of cerebellopontine angle pathology. The test was positive in 65% of the medium-sized tumours, in the entire material, 85%. The figures are higher than the incidence of trigeminal nerve symptoms. This in contrast to the reports of most authors. The tests described are simple and quick to perform, and it is emphasized that they should be applied to all patients with unilateral hearing loss of unknown origin.

A comparison of the speech audiograms of patients with bilateral and unilateral hearing loss due to Menière's disease has shown that when matched in respect of pure-tone hearing levels, speech discrimination at the better ear of the former is appreciably better than that at the impaired ear of the latter. In addition, while roll-over is a characteristic feature of the unilateral group it is conspicuously absent in the bilateral group. More surprisingly, in the bilateral group, despite relatively small differences in the pure-tone hearing levels at the two ears, speech discrimination at the better ear is strikingly superior to that at the poorer ear. It is concluded that patients with bilateral hearing loss selectively make use of the better ear to the neglect of the poorer ear. This could have important implications in the prescription of binaural hearing aids.

The effect of contralateral white noise stimulation on ipsilaterally presented click evoked brain stem potentials was examined. Continuous contralateral white noise does not influence the brain stem response components but pulsed white noise simultaneously presented with the clicks produced a central masking effect which was observed as an amplitude reduction confined to Wave V. Our findings confirm those of Zwislocki (1971) that pulsed noise is a more effective central masker than continuous noise. A computer addition of the responses to pulsed white noise and clicks recorded independently revealed no reduction in Wave V amplitude but the response to the two stimuli presented simultaneously showed a specific reduction in Wave V amplitude. No change in the latency of Wave V was observed to suggest any 'cross-over' masking of the click stimulus. Patients with total unilateral deafness did not exhibit this phenomenon. The effect of a time delay of the masker to one ear in relation to the click presented to the other ear reduced the amplitude of Wave V less than when the two stimuli were presented simultaneously. The reduction in the amplitude, being specific to Wave V, suggests that the effect is central and that the particular locus for this aspect of central masking is at the level of the inferior colliculus.

A 69-year-old man receiving monotherapy for lung cancer with dichloromethotrexate (DCM), and without exposure to other chemotherapeutic agents or known ototoxic drugs, developed profound cochleovestibular dysfunction. The initial presentation was vestibular. This resolved, but unilateral hearing loss ensued and continued to progress to a total of 80 db loss in the low frequency range and 40 db in the high range, despite discontinuation of the drug. Because DCM may be used in combination with the known ototoxin cisplatin, the potential of DCM as an ototoxin should also be considered in such patients.

(1955). Unilateral Deafness Following Latent Otitis. Acta Oto-Laryngologica: Vol. 45, No. 4, pp. 312-322.

Severe monaural hearing loss up to unilateral deafness cannot be treated with an ordinary hearing aid on the ear concerned. A microphone, however, can be placed in the vicinity of the bad ear and the sound transmitted to the external auditory canal of the good ear. This form of hearing aid treatment is called, in the literature, “Contralateral Routing of Signals”, CROS. The present investigation shows that such treatment may be advantageous. Nevertheless, under certain conditions, the treatment may lead to the comprehension of speech being worse than without an apparatus. Individual evaluation of the hearing problems of such patients is essential when considering whether treatment with CROS is to be recommended.

1. The loudness recruitment angle is defined. It is found to provide a useful quantitative index of the recruitment phenomenon.2. The results are described of a study of the angle based upon 200 cases of unilateral deafness due to Meniere's disease. The magnitude of the angle is found to vary linearly and within close limits, with the amount of the deafness.3. The recruitment angle shows some dependence upon the frequency characteristic of the deafness, being greater with low than with high frequency types of hearing loss.4. The results of a comparative study of two small selected groups of subjects, with and without severe symptoms, suggest that the recruitment angle tends to be increased during the active phases of the disease.5. The results are discussed in the light of recent work on the electromechanical behaviour of the cochlea, and an explanation is suggested of the neurological mechanism of the loudness recruitment phenomenon based upon the dual excitation theory of Hallowell Davis.

(1957). Hereditary Unilateral Deafness. Acta Oto-Laryngologica: Vol. 47, No. 4, pp. 303-311.

be referred to medical care as early as they are discovered or as it is possible for them to do it. However, there is another kind of remedial work to which I want to direct your special attention. It offers a real opportunity for effective measures with very little effort and does not require highly specialized assistance. It has been pointed out in these remarks that two very definite conditions exist. Namely, that the preponderance of hearing impairments among the pupils of the public schools is of the mild type, averaging only less than twenty-five per cent loss, and that a great factor in the handicaps of this type is adverse acoustic conditions. Many of the cases of hearing impairment-about one-third of the total cases-are seriously impaired in only one ear. This means that about all that is needed to meet the conditions of the majority of cases is careful seating so that they are placed in the most favorable location with reference to the principal sources of sound, supervision, and direction. In cases of unilateral deafness the best ear should be put forward, for it is possible to put the best ear forward just as it is to put the best foot forward. The fact that the component parts of speech sounds vary greatly in intensity or loudness raises the slight disabilities described to a point of major importance. The vowels contribute to the loudness of speech; but its intelligibility depends upon the initial and final consonants of the syllables. These consonants are extremely weak by comparison with the vowels and may be easily obliterated by slight losses.

During the period 1963-65, 28 cases of unilateral deafness with normal hearing in the other ear were found in Helsinki among 30,882 pupils. Twenty-seven children attended for examination. Etiology was unknown in 18 cases, mumps in 3, meningitis in 2, cerebral concussion in 2, measles in 1, and maternal rubella in 1. Electronystagmographic studies showed normal symmetrical reaction in 12 cases, canal paresis in both ears in 7, canal paresis in deaf ear in 4, and no response from deaf ear in 4. Radiologic examination showed normal mastoid cells in all cases. Abnormalities of the internal auditory canal were encountered in 6 cases. Ktiology of deafness in these six cases remained unknown.Das Gehor der Volksschulkinder in Helsinki wird in der 1., 3., 6. und 8. Klasse mit dem Audiometer gepruft. 1963-65 wurden unter 30 882 Schulern 28 Falle gefunden, die auf einem Ohr vollstandig taub waren, wahrend das andere normal horte. Die besprochene Untersuchung wurde an 27 Schulern mit cinem Durchsehnittsalter von 10 J...