When is a conductive hearing loss not a conductive hearing loss? Causes of a mismatch in air-bone threshold measurements or a "pseudoconductive" hearing loss

The otolaryngologist is sometimes faced with a patient with an apparent conductive hearing loss on audiometric testing who appears to have normal and mobile middle ear structures on ear exploration. Some causes of these "pseudoconductive" hearing losses can be diagnosed without resorting to surgery. This article reviews several possible mechanisms for this condition with diagnostic procedures to distinguish etiologic diseases. Conditions discussed include poor audiometry, functional hearing losses, "third window" causes, obliterated round window, abnormal inner ear connection with the cerebrospinal fluid space, inner ear mechanical conductive hearing loss, and apparent inner ear loss owing to missed middle ear pathology.     

Who wants a hearing aid? Personality profiles of hearing aid seekers

OBJECTIVE: Evidence indicates that elderly hearing-impaired people who use amplification live happier, healthier, and longer lives than those who do not. Nevertheless, only a small fraction (approximately 23%) of hearing-impaired adults actually seek and use hearing aids. This study explored the personalities of hearing aid seekers in an attempt to determine whether those who seek hearing aids are systematically different from the general population. DESIGN: In this cross-sectional survey, self-report data were obtained from 230 older adults with bilateral, symmetrical, sensorineural, mild to moderately severe hearing impairment. Subjects were representative of patients served either in a publicly funded hospital-based system (VA) or in a free-standing private practice system (PP). All subjects were seeking new hearing aids. Subjects completed a comprehensive personality questionnaire (NEO-Five-Factor Inventory) as well as questionnaires determining locus of control and preferred coping strategies. RESULTS: Individuals who seek amplification are not simply a random sample of the general population and presumably not a random sample of the hearing-impaired population. Compared with the typical adult, hearing aid seekers tended to be more pragmatic and routine-oriented and probably less imaginative in coming up with novel approaches to dealing with a complex problem such as hearing impairment. These individuals also were found to feel relatively more personally powerful in dealing with life's challenges. Further, hearing aid seekers reported using social support coping strategies less frequently than their non-hearing-impaired peers. In addition, there were significant differences in personality patterns between hearing aid seekers in the PP and VA systems. Differences noted in the personality traits of Openness and Neuroticism might be a useful guide to selecting treatment approaches and expectations for patients in each setting. Additional differences in Agreeableness imply that patients in the private practice system were more trusting than those in the general population, whereas this was not seen for patients in the public health VA system. One interpretation of this finding is that hearing-impaired individuals who are more suspicious and cynical are reluctant to try amplification in the PP system. This observation underscores the need to improve the public image of hearing health care to increase the uptake of hearing aids in general. CONCLUSIONS: Although individual hearing aid seekers display personality characteristics within the range of normal, this study suggested that they are not simply a random sample of the general population. Possible explanations are offered for significant personality differences, and potential clinical relevance is noted for some effects. The data also point to a need to improve the public image of hearing health care in the PP system.     

hearing and cochlear structures in a swine model

Objective To study the audition and inner ear structure in a normal swine model.Methods Auditory brainstem responses(ABRs) were determined in swine at 1 day and 1 month after birth.The form of the cochlea and hair cells were examined under a scanning electron microscope and on cochlear slices.Results ABR thresholds at 1 day and 1 month post-birth were between 40 and 50 dB SPL.The latencies of waves I,III and V in 1 day old swine were 1.97 ± 0.13,3.01± 0.16 and 4.26±0.20 ms,respectively.At 1 month,the lantan...     

Is hearing loss a feature of Joubert syndrome, a ciliopathy?

Objective

To assess if hearing loss is a feature of Joubert syndrome (JBS), one of the ciliopathies and therefore possibly associated with hearing loss.

Design

Retrospective case series.

Setting

University Children's Hospital.

Patients

Dutch patients with JBS.

Main outcome measures

Audiological data.

Results

Data from 22 Dutch Joubert syndrome (JBS) cases (17 males, 5 females) aged 3-40 years were available. Audiological tests were successfully performed in 14 cases. Three cases (aged 17-26 years) showed very mild sensorineural hearing loss (SNHL) at different frequencies. Conductive hearing loss due to middle ear infections occurred frequently in young JBS children (6 out of 22 cases). In three cases (aged 3-13 years) the parents reported the child was hypersensitive to sound.

Conclusion

We found no evidence for significant hearing loss in Joubert syndrome patients. However, given the compromised speech development in JBS, conductive hearing loss due to middle ear infections should be treated vigorously. SNHL at a later age cannot be excluded on the basis of our data, given the sample size. Three of the older cases showed discretely increased hearing thresholds. Analogous to the ciliopathy Bardet-Biedl syndrome, where hearing thresholds were reported to be subclinically increased in a group of adolescents patients, we recommend follow-up of JBS patients in view of the possibility of progressive, late-onset SNHL.     

Congenital hypothyroidism as a risk factor for hearing and parents’ knowledge about its impact on hearing

Aim:To evaluate the hearing of children with congenital hypothyroidism(CH)and to analyze the knowledge that parents’have on the possible auditory impacts of the disease.Methods:A total of 263 parents/guardians were interviewed about aspects of CH and hearing.Audiological evaluation was performed on 80 participants,divided into two groups:with CH(n?50)and without CH(n紏30).Clinical and laboratory CH data were obtained from medical records,pure tone auditory thresholds and acoustic reflexes were analyzed.The auditory data was compared between groups.Student’s t-test and Chi-square were used for statistical analysis at a significance level of 5%(p<0.05).Results:The majority(78%),of the parents were unaware that CH when not treated early is a potential risk to hearing.There was no correlation between socioeconomic class and level of information about CH and hearing(p>0,05;p=0.026).There was a statistically significant difference between the auditory tone thresholds of the groups and between the levels of intensity necessary for the triggering of the acoustic reflex.The group with CH presented the worst results(p<0.05)and absence of acoustic reflex in a normal tympanometric condition.Conclusions:Children with CH are more likely to develop damage to the auditory system involving retrocochlear structures when compared to healthy children,and that the disease may have been a risk factor for functional deficits without deteriorating hearing sensitivity.The possible impacts of CH on hearing,when not treated early,should be more publicized among the parents/guardians of this population.     

Can Rh antigens be a risk factor in noise-induced hearing loss?

Noise-induced hearing loss (NIHL) is one of the most common occupational problems and is one of the main causes of deafness. Many factors cause NIHL. Individual susceptibility is one of them. Rhesus (Rh) antigens and ABO blood groups can be factors in determining individual susceptibility. We aim to investigate the relationship between the Rh antigens and NIHL. The study was conducted in 438 factory workers who had been exposed to a noise level more than 85 dB for 8 h a day for a period of ≥15 years. The audiologic results and blood groups were obtained from the individual health records of the factory workers. We determined NIHL in 236 (53.9%) workers. Two hundred and nineteen (55.4%) of Rh-positive workers and seventeen (39.5%) of Rh-negative workers have NIHL, and the difference between the two groups was statistically significant (P < 0.05), whereas no statistically significant difference was determined between the NIHL and ABO blood groups. In conclusion, we suggest that the people with Rh-positive blood group are more prone to develop NIHL.     

Discrimination of envelope statistics reveals evidence of sub-clinical hearing damage in a noise-exposed population with ‘normal’ hearing thresholds

Noise exposure can affect the functioning of inner hair cells (IHC) within the cochlea, leading to a ‘noisy’ representation of the properties of sounds even when absolute thresholds are normal. This may lead to a reduced ability to discriminate sounds based on their statistical properties, especially for narrowband sounds presented at low levels, since such sounds excite only a small proportion of the IHCs. This idea was tested by requiring subjects to discriminate a Gaussian noise from a ‘low-noise noise’ with minimal envelope fluctuations. The noises were centred at 2, 3, or 4kHz. The stimulus duration required for threshold was measured as a function of sensation level (SL) for two groups of normal-hearing subjects, one rarely exposed to high-noise events (control group, C) and one frequently exposed to high-noise events (experimental group, X). For group X, threshold consistently rose for SLs below about 20dB, while for group C the threshold did not consistently rise at low SLs (although it did for a minority of subjects). The worsening in performance with decreasing level was significantly greater for group X than for group C.     

Autoimmune sensorineural hearing loss: is it still a clinical diagnosis?

Inner ear involvement with sensorineural hearing loss (SNHL) has been reported in many autoimmune disorders including ulcerative colitis. The pathogenetic mechanism of hearing loss in ulcerative colitis is thought to be immune mediated. Diagnostic tests are being developed to identify inner ear autoantibodies, that may be the cause of such hearing loss. The only test that is currently available for clinical use is the Otoblot test. This, however, tests only for antibodies against bovine heat shock protein 70 which is only one of the many cross-reacting proteins against the inner ear in suspected immune-mediated hearing loss. The clinical response to steroid therapy is thus the mainstay in the diagnosis of immune-mediated hearing loss. This paper presents a series of patients with clinically suspected autoimmune hearing loss. Diagnostic assays for this condition are discussed along with a review of the recent advances in the pathogenesis and laboratory diagnosis of immune-mediated sensorineural hearing loss.     

Progressive hearing loss after closed head injury: a predictable outcome?

OBJECTIVES: To evaluate the prevalence of progression of closed head injury (CHI)-induced hearing impairment, defined as > or = 15 dB HL deterioration at 1 or more frequencies, and to identify risk factors in patient history and initial status that could predict progression. MATERIAL AND METHODS: A total of 600 patients with major CHI were admitted to 2 Swedish medical centres during a 14-year period. The type of injury was established by means of CT and the severity of head injury was measured using the Swedish Reaction Level Scale (RLS). In 62 of these patients, pure-tone audiometry was performed soon after the injury. Forty-three patients agreed to participate in the present investigation, which was carried out 2-13 years after the injury. Each participant was evaluated using pure-tone audiometry and an itemized anamnesis was obtained. RESULTS: There was a higher prevalence of hearing impairments in the study group compared to a control group. Thirty-two subjects (74%,) showed a progression of > or = 15 dB, which was significantly greater than the spontaneous progression in the control group. Age and temporal bone fracture were risk factors for progression but not brain contusion only or RLS. There was an association between early pure-tone average (PTA) and progression as well as regression, i.e. the poorer the initial PTA the greater the progression as well as regression, indicating increased instability in the auditory system. Examination of patient histories did not reveal any single risk factors for progression. A serendipitous finding was a higher prevalence of reported memory shortcomings among those with post-traumatic tinnitus. CONCLUSION: Especially for those with fracture of the temporal bone the present results stress the importance of audiometric evaluation and follow-up, from both rehabilitation and medicolegal perspectives,     

a report of who ear and hearing disorders survey in guizhou province

Objective To report a population-based survey on the prevalence, pathogenic factors and medical needs of ear diseases and hearing loss. Methods Using the probability proportion to size (PPS) method, 6626 residents were investigated in 30 clusters in accordance with the WHO protocol. Results The prevalence of hearing loss was 17.1%(compatible with the natioanal standardized rate of 17.6%), including mild (11.0%), moderate (4.2%), severe (1.4%), and profound (0.5%)impairment. Of the 1131 individuals with hearing loss, 663 (20.2%) were male and 468 (14.0%) were female. The prevalence of hearing disability was 6.1%(again compatible with the national standardized rate of 6.5%). The causes of hearing loss were ear diseases (31.4%), non-infectious ear disorders (42.5%), genetic disorders (6.7%), infectious disease (0.4%) and undetermined causes (29.3%). Of the hearing impaired people, 13.8% needed otologic and/or audiologic interventions and 9.1% needed hearing aids. Conclusion The prevalence of hearing loss and hearing disability have increased in the past twenty years. The data pro-vide important information for authorities in formulating policies for prevention and management of deafness.     

Does the bone-anchored hearing aid have a complementary effect on audiological and subjective outcomes in patients with unilateral conductive hearing loss?

OBJECTIVES: To study the effect of a bone-anchored hearing aid (BAHA) in patients with unilateral conductive hearing loss. STUDY DESIGN: Prospective evaluation on 18 subjects. METHODS: Aided and unaided binaural hearing was assessed in the sound field using a sound localization test and a speech recognition in noise test with spatially separated sound and noise sources. The patients also filled out a disability-specific questionnaire. PATIENTS: 13 out of the 18 subjects had normal hearing on one side and acquired conductive hearing loss in the other ear. The remaining 5 patients had a unilateral air-bone gap and mild symmetrical sensorineural hearing loss. RESULTS: Sound localization with the BAHA improved significantly. Speech recognition in noise with spatially separated speech and noise sources also improved with the BAHA. Fitting a BAHA to patients with unilateral conductive hearing loss had a complementary effect on hearing. Questionnaire results showed that the BAHA was of obvious benefit in daily life. CONCLUSIONS: The BAHA proved to be a beneficial means to optimize binaural hearing in patients with severe (40-60 dB) unilateral conductive hearing loss according to audiometric data and patient outcome measures.     

Can a hearing education campaign for adolescents change their music listening behavior?

This study looked at whether a hearing education campaign would have behavioral effects on the music listening practices of high school students. A total of 1757 students participated in a hearing education campaign. Before the campaign and one year thereafter they completed a survey asking for: (1) average frequency of discotheque attendance, (2) average duration of stay in the discotheque, (3) use of earplugs in discotheques, (4) frequency of regeneration breaks while at a discotheque, and (5) mean time per week spent listening to music through headphones. On questions (2), (3) and (5) no relevant post-campaign changes were reported. On question (1) students' answers indicated that the frequency of discotheque attendance had even increased after the campaign. The only change in keeping with the purpose of the campaign was an increase in the number of regeneration breaks when at a discotheque. The effect of hearing education campaigns on music listening behavior is questioned. Additional efforts are suggested to encourage adolescents to adopt protective behaviors.     

Early detection of hearing impairment in a developing country: what options?

The concept of early detection is often predicated on a specified time-interval for optimal neural development in early childhood. This has been facilitated by advances in objective screening methods such as auditory brainstem response (ABR) and otoacoustic emissions (OAE). However, the prospects for this trend in developing countries remain doubtful, because of adverse socio-economic conditions. Consequently, the relative effectiveness of available tests was evaluated to determine the most viable option for mass screening based on findings from a broader study among 359 school entrants (mean age 6.7 years) in Lagos. The specificity of the questionnaire for detecting hearing loss was 94.0 per cent as against 62.4 per cent for otoscopy and 84.0 per cent for tympanometry. The sensitivities for the three methods were 10.0 per cent, 56.0 per cent and 52.0 per cent, while the positive predictive values were 21.7 per cent, 19.4 per cent and 34.6 per cent respectively. Notwithstanding its limitations, the administration of a well-structured questionnaire at school entry, complemented with parental education, may constitute the inevitable and immediate option for an early detection program in a developing country.