Mid-frequency sensorineural hearing loss: aetiology and prognosis

OBJECTIVES: An audiometric finding of mid-frequency sensorineural hearing loss (MFSNHL), or a U-shaped pattern, is uncommon. The objective of this study is to investigate the aetiology and prognostic significance of MFSNHL. DESIGN: Tertiary academic referral centre-based retrospective case review and review of audiograms to determine the prevalence of this audiometric finding. METHODS: Patients with a pure tone threshold average at 1, 2, and 4 kHz at least 10 dB greater than the average at 0.5 and 8 kHz were included in this study; 35 patients met these criteria. The mean age of the patients was 34.6 years old (range 4-71 years). Twelve patients (33 per cent) were under 18 years of age. Serial audiograms were obtained for 14 patients. The notes were reviewed for any pertinent otologic history, subsequent diagnoses, management and disease course. RESULTS: The prevalence of MFSNHL in this practice setting is less than 1 per cent. The average hearing threshold in the mid-frequencies was 44 dB, which was 17 dB and 20 dB lower than at 0.5 Hz and 8 kHz, respectively. The pure tone average (0.5, 1, 2 kHz) was 40 dB. Sixteen patients (44 per cent) required amplification. Of all patients, 22 had hereditary hearing loss, eight had idiopathic hearing loss, and five adults had vestibular schwannomas. CONCLUSIONS: MFSNHL is an infrequent audiometric finding. The great majority of these cases are of presumed hereditary or idiopathic aetiology, although 22 per cent of adults had vestibular schwannomas. This series presents the causes and prognosis of this audiometric pattern.     

The prevalence of hearing impairment amongst Maori schoolchildren

A survey of hearing amongst a population of Maori schoolchildren in the eastern North Island of New Zealand has demonstrated a high prevalence of hearing impairment. Out of 194 children undergoing audiometry an impairment of 20 dB or greater at 0.5, 1.2 and 4 kHz was found in the worse hearing ear in 29% and in the better hearing ear in 12%. Comparison with a similar survey done in the same valley in 1977 revealed an apparent reduction in the prevalence of hearing loss and the prevalence of otitis media. This improvement appears to be due to a reduced prevalence of otitis media. An unexpected finding was that at least 2% of the children had a bilateral sensorineural hearing impairment.     

Prevalence of hearing loss in primary school children in Zimbabwe

OBJECTIVE: The objective of the study was to determine the prevalence of significant hearing impairment in children attending primary school in the country of Zimbabwe. METHODS: A cross-sectional study of the prevalence of hearing impairment in primary school children was undertaken as part of The Rotary Hearing Health Care Program in Zimbabwe. The sampling unit was primary schools in Manicaland, a province of Zimbabwe. All students in selected schools were screened. In total, 5528 students were screened for significant hearing impairment defined as greater than 30 dB HL at 1, 2 and 4 kHz in a quiet classroom. RESULTS: Overall, 135 students (2.4%, 95% CI 2.0-2.8) were identified as having a hearing threshold of greater than 30 dB in at least one ear and for at least one of the test frequencies. A conductive hearing loss was found in 79 students, or 1.4% of the total, and a sensorineural hearing loss was found in 56 students or 1.0% of the total. Disabling hearing impairment was found in 0.9% of children. CONCLUSIONS: The prevalence of hearing impairment in children in Zimbabwe is significant, even as a conservative measure amongst children attending school. Hearing impairment challenges the academic, career and social potential of young children. Regular screening, such as this could help target preventative measures that may improve the hearing impaired child's potential in terms of social interaction, academic achievement, and work opportunities.     

The effect of mild hearing loss on academic performance in primary school children

Objectives

To determine the prevalence of mild hearing loss and its association with academic performance among primary school children.

Patients and methods

A comparative cross sectional study was conducted on standard (grade) five school children in a state in Malaysia. Five schools were selected by using simple random sampling. There were three classes (A, B and C) of standard five in each school. Student's selection into these classes was made by respective school administration based on their final term examination in standard four. Class A was for the best academic achievers while class C was for the poorest. Ear examinations were done followed by pure tone audiometry for confirmation of the hearing status. In this study, mild hearing loss was defined as an average threshold of 20-39 dB at 0.5, 1, 2 and 4 kHz. Data analysis was done using SPSS Version 12.0 software. Chi-square test was used to determine the association between mild hearing loss and academic performance. The significant level was set at p = 0.05.

Results

From a total of 257 students, 234 have completed the examinations (response rate = 91.0%). Fifty-three percent of them were boys while 47% were girls. A hundred and forty-nine (63.7%) of them were from class A while 85 (36.3%) were from class C. The prevalence of hearing loss in our school population was 15% (95% CI: 11.0-20.0%). Thirty-two (88.9%) of them were having conductive type. Out of the total, 38.9% were having problems in both ears. The students who have poor academic performance have been shown to be significantly associated with mild hearing loss (p < 0.001).

Conclusions

There was a high prevalence of mild hearing loss among primary school children. This problem could affect their academic performance. Therefore, hearing assessment is highly recommended to be done on every child especially to those who have poor academic achievement.     

Hearing loss in school children. A longitudinal study of sensorineural hearing impairment

In a longitudinal study, 2325 children were hearing tested at age 7, 10 and 13 with screening audiometry. The screening level was 20 dB HL. Approximately 75% of the children passed the screening level at all ages. Hearing loss was more frequent in boys than in girls at age 13 (16%:9%). The left ear was more commonly affected than the right ear. High frequency dips increased for boys with age, but not for girls. The increasing incidence of hearing loss for boys with age is probably due to noisy leisure time activities.     

Unilateral hearing loss in children

Recent reports suggest that early onset, severe unilateral sensorineural hearing loss (USNHL) in children may be associated with significant deficits in auditory and psycholinguistic skills and school performance. This report reviews a consecutive series of 324 children and adolescents (202 males, 122 females) with documented USNHL evaluated at the Boys Town National Research Hospital. The left ear was affected in 168 (52%) and the right ear in 156 (48%). Based on speech frequency threshold averages (i.e., 500, 1000, and 2000 Hz), the losses were classified by severity as follows: borderline, 43 (13%); mild, 51 (16%); moderate, 40 (12%); severe, 19 (6%); profound, 31 (10%), and anacusic, 50 (15%). The remaining 90 children (28%) had high frequency losses (i.e, above 2000 Hz). The mean and median age of diagnosis were 8.78 years and 7.75 years. Temporal bone imaging studies, auditory brainstem responses (ABRs), and vestibular evaluations were performed on selected cases. Etiology was uncertain in 34.8% of cases, while hereditary factors (12.6%), head trauma (10.8%), and perinatal risk factors (10.7%) were the most commonly identified etiologies. Thirty-one percent of the children had scholastic or behavioral problems in school. A concerted effort aimed at early identification and intervention in cases of USNHL is warranted.     

Functional hearing loss in children

The cases of children diagnosed with pseudohypacusis in the Department of Pediatric Otolaryngology were presented. Probable mechanism of its pathogenesis was described. The main stress was put on its correct diagnosis particularly in children with co-existing organic changes. Diagnosis of pseudohypacusis in children is not problematic provided that the occurence of this disease is taken into consideration during diagnostic procedures.     

Functional hearing loss in children

This report reviewed 39 school-age children diagnosed as having a functional hearing loss utilizing auditory brainstem response (ABR) audiometry during the past 5 years at the Department of Otolaryngology, Kyushu University Hospital in Japan. Twenty-seven cases were females and 12 were males. Seven cases had a hearing loss unilaterally and 32 bilaterally. Although pure-tone audiometry revealed a variety of audiogram shapes, two-thirds of the cases had a flat or saucer-shaped audiogram with a mild to moderately severe hearing loss. ABR audiometry for the frequencies of 1, 2 and 4 kHz indicated a normal hearing threshold in 65 ears of 35 patients, and mild threshold elevations of at least one frequency in the remaining 6 ears of 4 patients. Three illustrative cases were demonstrated, and a discussion was held regarding the features in audiometric tests, and environmental factors surrounding the children with this condition. We emphasized that the physiological hearing measurement such as ABR audiometry should be performed when any discrepancy was noted between the patient's history and results of pure-tone audiometry, because of not infrequent occurrence of functional hearing loss.     

Sensorineural hearing loss in children

Sensorineural hearing loss in children, either congenital or acquired, has an incidence of 2-4 per million. Molecular diagnosis of early childhood deafness became available for some types of syndromal and non-syndromal forms and will offer different treatment modalities in the future. Severe to profound sensorineural hearing loss can be effectively treated with cochlear implants. There is evidence of cerebral auditory plasticity under electrical stimulation of the auditory nerve with better performance in early implanted children. Other predicting factors are related to the type of schooling, family support and residual hearing. In the long-term, prelingually deafened children will develop considerable speech perception and production. Children with marginal benefit from hearing aid amplification show significant improvements in speech perception following implantation. Implantation is also possible in cases of cochlear malformation. However, special attention has to be given to the facial nerve, a possible CSF leak and electrode misplacement. Apart from hearing improvement cochlear implants have a positive impact on the family situation, schooling and personal well-being.     

Prevalence of occupational noise induced hearing loss amongst traffic police personnel

Traffic branch personnel of Pune traffic police were screened for presence of noise induced hearing loss. A very significant number (81.2%) showed sensorineural hearing loss. The various factors responsible for noise induced hearing loss are discussed.     

Chronic suppurative otitis media in school going children

The morbidity and mortality associated with otitis media is really a challenge for the health care systems. This study is a small attempt to look into the magnitude of this problem in the society, where in school going children in Yavatmal city were studied. A total of 4104 students were studied. It was found that the overall prevalence of chronic suppurative otitis media in Yavatmal city is 3%. The incidence of acute otitis media was found to be 1.3% Chronic suppurative otitis media was commoner in students belonging to low socioeconomic strata and its association with adenoid hypertrophy was statistically significant. The authors recommend that a few more such studies should be carried out in different parts of the country to collect vital data for the health care system managers. Suppurative otitis media, school children, Yavatmal city.     

Tinnitus prevalence in industrial hearing loss compensation claimants

In a study of 3466 claimants for noise-induced occupational hearing loss tinnitus was reported by half of the patients. Its characteristics in this select group were different from tinnitus seen in other groups. Specifically, tinnitus prevalence seemed to be independent of age, state of hearing and duration of noise exposure if greater than 10 years. The reasons for these differences are unclear, though the possibility of financial motivation by some claimants is raised. Further work in this area is urgently required to achieve standardization and objectivity. Being a subjective complaint these aims will be difficult to accomplish. However not until then can a fair handicap scale be developed for workers who develop this disquieting symptom as a result of their occupation.     

Novel-word learning in children with normal hearing and hearing loss

OBJECTIVE: The goal of this study was to assess performance on a novel-word learning task by normal-hearing and hearing-impaired children for words varying in form (noun versus verb), stimulus level (50 versus 60 dB SPL), and number of repetitions (4 versus 6). It was hypothesized that novel-word learning would be significantly poorer in the subjects with hearing loss, would increase with both level and repetition, and would be better for nouns than verbs. DESIGN: Twenty normal-hearing and 11 hearing-impaired children (6 to 9 yr old) participated in this study. Each child viewed a 4-minute animated slide show containing 8 novel words. The effects of hearing status, word form, repetition, and stimulus level were examined systematically. The influence of audibility, word recognition, chronological age, and lexical development also were evaluated. After hearing the story twice, children were asked to identify each word from a set of four pictures. RESULTS: Overall performance was 60% for the normal-hearing children and 41% for the children with hearing loss. Significant predictors of performance were PPVT raw scores, hearing status, stimulus level, and repetitions. The variables age, audibility, word recognition scores, and word form were not significant predictors. CONCLUSIONS: Results suggest that a child's ability to learn new words can be predicted from vocabulary size, stimulus level, number of exposures, and hearing status. Further, the sensitivity to presentation level observed in this novel-word learning task suggests that this type of paradigm may be an effective tool for studying various forms of hearing aid signal processing algorithms.     

Functional hearing loss in children who were not aware of their hearing loss

We investigated one hundred and fourteen ears of 60 children (8 males, 52 females, aged from 6 to 13 years) with diagnoses of functional hearing loss (FHL), and were not aware of their own hearing loss. Forty nine (81.7%) of 60 cases examined were detected by school screening tests, 6 (10.0%) were referred to our hospital because their families noticed poor hearing responses, and 5 (8.3%) were enrolled because they complained of otalgia or discomfort in the ear. Forty (66.7%) showed only pure tone threshold loss without complications, and the remaining 20 associated nonorganic disorders. In addition, our investigation found 11 cases (18.3%) with nonorganic otalgia, 5 (8.3%) with functional visual disturbance, 1 (1.7%) with enuresis nocturna who refused to attend school, 1 with tinnitus, 1 with vertigo, and 1 with tic. Moreover, 11 (18.3%) of the 60 cases were suspected of being in conflict with school and/or home. The Type V Békésy pattern, which is frequently observed in FHL and it has clinical utility to distinguish FHL from other types of organic hearing loss, was detected in 44 ears (38.6%). Fifty two (45.6%) of 114 ears showed normal pure-tone thresholds during the clinical course. Sixteen (14.0%) ears needed more than 1 year for thresholds to normalize. These findings suggest that some FHL cases without awareness of their hearing loss resemble psychogenic hearing loss. In such cases, otolaryngologists should carefully check the patient's individual circumstances, and when appropriate, refer patients for psychiatric consultation.     

儿童突发性感音神经性聋发病特点分析

目的 :探讨儿童突发性感音神经性聋 (突发性聋 )的发病特点 ,以指导临床诊断与治疗。方法 :总结2 1例 14岁以下突发性聋患儿 (儿童组 )的临床表现及预后等 ,并与 6 7例成年突发性聋 (对照组 )进行对比分析。结果 :儿童组中 11例 (5 2 .4 % )查到可能的病因 ,其中腮腺炎 4例 (19% )、上呼吸道感染 3例 (14 .3% )、耳毒性药物中毒 2例 (9.5 % )、声损伤和代谢性脑病各 1例 ;对照组 19.4 %找到可疑的病因。入院时儿童组听力受损平均88.6dB ,对照组 80 .2dB ,两组差异有统计学意义 (P <0 .0 5 ) ;治疗后儿童组听力平均提高 14 .3dB ,对照组提高37.8dB ,两组差异有统计学意义 (P <0 .0 5 )。结论 :儿童突发性聋的特点多有明确病因 ,其中以病毒感染多见 ,其耳聋程度重 ,预后较成人差     

Simulated conductive hearing loss in children

Otitis media with effusion (OME) often results in hearing loss for children with the condition. In order to provide appropriate and effective audiologic management, it is important to understand the impact of OME on speech recognition ability when hearing loss is present. This study examined the speech recognition abilities of normal-hearing six- and seven-year-old children (n = 12) and adults (n = 12) using monosyllabic words and nonsense syllables presented at two levels of simulated conductive hearing loss characteristic of OME. Average speech recognition scores decreased as the degree of simulated conductive hearing loss increased. Both age groups scored significantly poorer for nonsense syllables than for monosyllabic words. In general, the children performed more poorly than the adults with the exception of the easiest listening condition for word stimuli. Furthermore, children appeared less able than adults to use their knowledge of familiar words to improve performance. These findings suggest that rehabilitative strategies may best be focused on combining familiarization techniques and amplification options.