Noise exposure and hearing impairment among Chinese restaurant workers and entertainment employees in Hong Kong.

BACKGROUND: Noise-induced hearing loss (NIHL) is a major concern in the non-manufacturing industries. This study aimed to investigate the occupational noise exposure and the NIHL among Chinese restaurant workers and entertainment employees working in the service industry in Hong Kong. METHODS: This cross-sectional survey involved a total of 1,670 participants. Among them, 937 were randomly selected from the workers of Chinese restaurants and 733 were selected from workers in three entertainment sectors: radio and television stations; cultural performance halls or auditoria of the Leisure and Cultural Services Department (LCSD); and karaoke bars. Noise exposure levels were measured in the sampled restaurants and entertainment sectors. Each participant received an audiometric screening test. Those who were found to have abnormalities were required to take another diagnostic test in the health center. The "Klockhoff digit" method was used to classify NIHL in the present study. RESULTS: The main source of noise inside restaurants was the stoves. The mean hearing thresholds showed a typical dip at 3 to 6 KHz and a substantial proportion (23.7%) of the workers fulfilled the criteria for presumptive NIHL. For entertainment sectors, employees in radio and television stations generally had higher exposure levels than those in the halls or auditoria of the LCSD and karaoke bars. The mean hearing thresholds showed a typical dip at 6 KHz and a substantial proportion of the employees fulfilled the criteria for presumptive NIHL (38.6%, 95%CI: 35.1-42.1%). Being male, older, and having longer service and daily alcohol consumption were associated with noise-induced hearing impairment both in restaurant workers and entertainment employees. CONCLUSION: Excessive noise exposure is common in the Chinese restaurant and entertainment industries and a substantial proportion of restaurant workers and entertainment employees suffer from NIHL. Comprehensive hearing conservation programs should be introduced to the service industry in Hong Kong.

Short electrode insertion in cochlear implantation: speech perception performance of Cantonese-speaking subjects.

CONCLUSIONS: Subjects with cochlear ossification derived benefits in terms of speech performance similar to those of the non-ossified group. It is thus recommended that the insertion of short electrode arrays should be considered an alternative choice for patients with cochlear ossification. OBJECTIVE: Cochlear ossification has been recognized as a major obstacle to the full insertion of a multichannel cochlear implant electrode array. To alleviate the technical difficulty of placing a standard electrode array and the possibility of causing undesirable trauma to the cochlea, a newly designed electrode array with the same number of electrodes compressed into a shorter length has been made available. The aim of the present study was to examine the speech perception performance of patients implanted with the MED-EL C40+S compressed electrode array and to compare their results with those of matched groups implanted with the MED-EL C40+standard electrode array. MATERIAL AND METHODS: One pre-lingually and two post-lingually deaf subjects using short electrode arrays were matched with three groups of subjects using standard electrode arrays. The pre- and postoperative speech perception scores were evaluated. RESULTS: All three subjects using compressed electrode arrays achieved speech perception scores comparable to those of matched subjects using standard electrode arrays. There was also a tendency for the subjects to show similar patterns of speech perception scores as a function of the difficulty of the tests.

Translation of the dizziness handicap inventory into Chinese, validation of it, and evaluation of the quality of life of patients with chronic dizziness.

The aims of this study were 1) to translate the Dizziness Handicap Inventory (DHI) into Chinese and to validate it and 2) to use the Chinese DHI and the Chinese (Hong Kong) Short Form-36 Health Survey (Chinese [HK] SF-36) to evaluate the quality of life (QoL) of patients with chronic dizziness. Seventy-one patients with 6 months of dizziness due to vestibular dysfunction were evaluated initially, 7 days later (n = 49), and after 7 months of medical treatment (n = 17). The Chinese DHI has been shown to retain good test-retest reliability (intraclass correlation coefficient range, 0.64 to 0.87) and internal consistency (Cronbach alpha coefficient > 0.7) as compared to the original DHI and has a moderate responsiveness (0.54). We find the Chinese DHI to be a valid tool for evaluation of QoL of Chinese patients with dizziness. Low mean scores on the Chinese DHI and Chinese (HK) SF-36 signify that chronic dizziness has a considerable impact on the QoL of these patients.

Superiority of bilateral cochlear implantation over unilateral cochlear implantation in tone discrimination in chinese patients.

PURPOSE: The benefits of bilateral cochlear implants (CIs) versus unilateral CIs were evaluated by comparing the Cantonese lexical tone discrimination scores conducted in a quiet environment and against a background noise. MATERIALS AND METHODS: Four postlingually deafened Cantonese-speaking adults (2 men and 2 women) with bilateral CIs were included in this study. The subjects were their own control in the monaural hearing condition. Both the Cantonese lexical tone stimuli and the speech-weighted background noise were presented at 0(0) azimuth and at a distance of 1 m from the subject. The speech stimuli, which were maintained at 65 dB sound pressure level, were presented in both a quiet environment and against a background noise at signal to noise ratios (SNRs) of +15, +10, +5, 0, -5, -10, and -15. RESULTS: Against a background noise, the bilateral CIs required +5 dB SNR only to obtain significant scores in discriminating Cantonese lexical tones and to achieve discrimination scores that were comparable to the optimal discrimination scores obtained in quiet. No significant difference in the discrimination scores was observed between binaural and monaural hearing conditions when the tests were conducted in quiet. CONCLUSIONS: Our study showed that in the presence of background noise, bilateral CIs were better than unilateral CIs in discriminating Cantonese lexical tones.

[Radiological study of temporal bone in children with profound deafness before cochlear implant: CT vs magnetic resonance imaging].

OBJECTIVE: To evaluate the clinical application of magnetic resonance imaging (MRI) and CT in children with profound deafness before cochlear implant and their impact on surgical decision. METHODS: The pre-operative CT and MRI data from 71 children with bilateral profound deafness planned for cochlear implant were studied. RESULTS: 12 patients showed enlarged vestibular aqueduct (16.9%); 14 patients had Mondini malformation (19.7%); 3 patients demonstrated enlarged internal auditory meatus (4.2%); and 2 patients were suspected to have fistulae (2.8%) on both CT and MRI examinations. In comparison between MRI and CT, unilateral cochlear fibrosis was detected in 5 patients(7%) by MRI, but none by CT scans. Bilateral dehiscent facial nerve was detected in 1 patient(1.4%) by CT scan, while MRI was normal. CONCLUSION: CT and MRI are essential for the pre-operative planning of cochlear implant, especially in patients with enlarged vestibular aqueduct, Mondini malformation, enlarged internal auditory meatus and suspected fistulae. These two imaging modalities are complementary to each other in cases with cochlear fibrosis and facial nerve dehiscence.