1996 Fiscal Year Final Research Report Summary
The Age Variation of Hearing among Chinese Farmers
| Project/Area Number |
07045055
|
|---|
| Research Category |
Grant-in-Aid for international Scientific Research
|
| Allocation Type | Single-year Grants |
|---|
| Section | University-to-University Cooperative Research |
|---|
| Research Institution | Wakayama Medical University |
|---|
Principal Investigator |
MIYASHITA Kazuhisa Wakayama Medical University, Professor, 医学部, 教授 (50124889)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
林 忠輝 山東医科大学, 講師
ほう 培良 山東医科大学, 衛生学部, 助教授
張 衡 山東医科大学, 副校長
王 廷礎 山東医科大学, 校長
MORIOKA Ikuharu Wakayama Medical University, Associate Professor, 医学部, 助教授 (70264877)
YAMANAKA Noboru Wakayama Medical University, Professor, 医学部, 教授 (10136963)
TAKEDA Shintaro Nursing College, Wakayama Medical University, Professor, 看護短期大学部, 教授 (70073690)
LIN Zhang Hui Shandong Medical University, Ent Attending & Lecturer
HAO Pei Liang Shandong Medical University, Associate Professor
ZHANG Heng Shandong Medical University, Vice President
WANG Ting Chu Shandong Medical University, President
|
|---|
| Project Period (FY) |
1995 – 1996
|
| Keywords | hearing acuity / age-related change / hearing level / upper limit of hearing / normal aging curve / difference / rural Chinese / urban Chinese |
|---|
| Research Abstract |
To clarify the effects of environmental noise on the age-related changes in hearing, the joint research between Wakayama Medical University in Japan and Shandong Medical University in China was conducted. The subjects were 1064 male and 1273 female Chinese who were occupationally unexposed to noise ranging in age from 5 to 83 years. Audiometric threshold testing was performed at the audiometric frequencies of 0.5,1,2,4 and 8 kHz. The upper limit of hearing was also measured. The ears of subjects with no evidence of hearing impairment were selected to analyze the hearing level and the upper limit of hearing. The subjects finally accepted comprised 1604 male and 2223 female normal ears. Normal aging curves of hearing level at each frequency and upper limit of hearing were established by calculating the 25th, 50th and 75th percentiles for each age group. The hearing level gradually increased with age and rapidly over 50 years. Deterioration of the upper limit of hearing was observed from early childhood and slight between age 25 and 49 but at ages over 50 it was accelerated. The age-related changes in hearing of Chinese were compared with those of Japanese normal group. Those of Chinese were slower than those of Japanese. When the age-related changes in hearing of urban Chinese were compared with those of rural Chinese. Those of urban Chinese were faster than those of rural Chinese. These differences may be the effects of environmental noise. In this study, 370 subjects (16% subjects) were excluded from the normal groups because of hearing impairment, 223 of them showed sensory hearing loss. Logistic regression analysis was used to analyze the items related to hearing impairment. Odds ratio of otitis media was the highest. This might come from the effect of aminoglycoside antibiotics commonly used to treat otitis media.
|
