No abstract available.
Bone Conduction* ; Tympanoplasty*

No abstract available.
Bone Conduction* ; Otitis Media* ; Otitis*

Bone Conduction ; Hearing Aids ; Humans

Bone Conduction ; Hearing Aids ; Humans

To evaluate the effect of mastoidectomy and posterior tympanotomy on postoperative hearing, 101 cases of type I tympanoplasty operated by one operator were retrospectively reviewed. The patients were divided into three groups; Group I(N=14) was the type I tympanoplasty without mastoidectomy ; Group II(N=44) was the type I tympanoplasty with simple mastoidectomy ; Group III(N=43) was the type I tympanoplasty and mastoidectomy with posterior tympanotomy. The type of operation was determined by preoperative physical finding, radiological findings, and decision was finally made during the operation. Preoperative mean air-bone gaps of pure tone average were significantly different among three groups(group I;13 dBHL; group II ; 22 dBHL, group III ; 31 dBHL). There was no significant difference of the postoperative air-bone gap gains at speech frequencies among three groups and the average gain was about 9 dBHL at 3 months, 11 dBHL at 6 months. respectively. However, the postoperative hearing was significantly changed according to the types of operation in the air and bone conduction, specially in the high tone area. At the 4 kHz, postoperative bone conduction did not changed significantly in the group I and II, however, postopearive bone conduction significantly worsened from 14 dBHL to 20-22 dBHL in the group III. In the same time, air conduction at 8 kHz was significantly aggravated from 52 dBHL to 65 dBHL postoperatively in the group III.
Bone Conduction ; Hearing* ; Humans ; Retrospective Studies ; Tympanoplasty

No abstract available.
Bone Conduction* ; Ear, Middle* ; Otitis Media* ; Otitis* ; Pathology* ; Temporal Bone*

This study was performed to evaluate the effects on hearing of video tape manufacturing workers exposed to organic solvents. The experimental groups included solvents exposed group 51 and unexposed group 57 workers. All workers was examined air and bone conduction sensitivity by pure tone audiometer. The mean age of solvents exposed group was 34.1 and nonexposed group was 35.8. The mean duration of solvents exposed group was 7.3years. High frequency hearing loss prevalence of both groups was 23.5% in the group exposed to organic solvents and 17.5% in nonexposed group. There is no statistical significants in the prevalence of high frequency hearing loss. According to comparison of mean auditory threshold value by frequencies, on the air conduction test, right was statistically significant in the 250, 500, 1000, 2000, 4000Hz, except 8000Hz. Left 250, 500, 1000Hz was statistically significant. On the bone conduction test, left250, both 500, 1000, 2000, 4000Hz, except right 250Hz, was statistically significant difference. Generally, auditory sensitivity threshold of the exposed group was higher than the nonexposed group.
Auditory Threshold ; Bone Conduction ; Hearing Loss ; Hearing* ; Prevalence ; Solvents*

BACKGROUND AND OBJECTIVES: A free-beam-type CO₂ laser, which use a micromanipulator mounted on a microscope as the delivery system, has the merit of not being affected by hand tremor at the time of shooting. However, this delivery system has several disadvantages, including a restricted operation range and a risk of incorrect focusing. A fiber-type CO₂ laser uses a hand-held delivery system and has the opposite merits and demerits. We compared the results of stapes surgery with free-beam and fiber type delivery systems. SUBJECTS AND METHODS: The study enrolled 36 patients who underwent stapedotomy with free-beam- (n=26) or fiber- (n=10) type CO₂ lasers. The air-bone (AB) gap closure, bone conduction (BC) change, and operating time were evaluated. The AB gap closure was calculated by subtracting the preoperative BC thresholds from the postoperative air conduction thresholds. The BC change was calculated by subtracting the postoperative BC thresholds from the preoperative BC thresholds. RESULTS: The mean operating time was significantly (p=0.035) shorter in the fiber-type group (72.5±8.2 min) than in the free-beam-type group (80.5±11.4 min). The mean AB gap closure did not differ significantly (p=0.297) between the free-beamand fiber-type groups (5.8±10.1 and 1.4±6.8 dB, respectively). The mean BC change did not differ significantly (p=0.873) between the free-beam- and fiber-type groups (2.4±6.9 and 2.8±5.3 dB, respectively). The hearing outcomes did not differ significantly between the two groups. CONCLUSIONS: Operating times were significantly shorter using the fiber-type CO₂ laser, while hearing outcomes did not differ significantly between the two groups.
Bone Conduction ; Hand ; Hearing ; Humans ; Otosclerosis ; Stapes Surgery* ; Stapes* ; Tremor

BACKGROUND AND OBJECTIVES: The reports of normative measurements for inner ear structure using computer-based programs are rare. The purpose of this study was to measure the normative data of the Korean inner ear structures and establish the basic data for diagnosis of congenital inner ear anomaly. SUBJECTS AND METHOD: Temporal bone CT of 38 patients (16 men and 22 women) without apparent disease of middle and inner ear, fractures or major disorder such as seizure or tumor were retrospectively reviewed. Fifteen dimensions on axial views and 9 dimensions on coronal views were measured in PACS using pi-view program. The slice thickness of CT was 0.6 mm. RESULTS: From the axial view, the canal diameter of SSCC was 1.09+/-0.15 mm, the bony island width was 5.70+/-0.50 mm, the bony island width of LSCC was 3.99+/-0.58 mm, the cochlear upper turn width & height were each 5.63+/-1.07 and 3.03+/-0.65 mm. The vestibular aqueduct were observed 95.3%. From the coronal view, the cochlear height was 5.14+/-0.36 mm. The length of IAC was significantly longer in male than female (p<0.05) and the opening site of IAC was significantly wider in the left than the right (p<0.05). The upper turn of cochlea in good bone conduction (< or =10 B) had larger width and smaller height than those in poor bone conduction (>10 dB). CONCLUSION: We established the Korean normative measurements of the inner ear structures, which can be used for further diagnosis of the inner ear anomaly.
Bone Conduction ; Cochlea ; Diagnosis ; Ear, Inner* ; Female ; Humans ; Male ; Retrospective Studies ; Seizures ; Temporal Bone* ; Vestibular Aqueduct

OBJECTIVE: This study was undertaken to evaluate that noise-exposed workers have been appropriately selected for the special periodic health examination and that pure-tone audiometry has been correctly applied and the results of these have been properly analyzed. METHODS: We obtained health examination data of noise-exposed workers from 48 special periodic health examination agencies. The data consisted of special periodic health examination results and audiograms that had performed examination during the latter half of 1998. We analysed the appropriateness of the subject selection for the second special periodic health examination of noise-exposed workers, the method of pure-tone audiometry, and the evaluation of audiogram. RESULTS: The screening performance rate is 67.65% in the special periodic health examination of noise-exposed workers. Although 34.29 persons per agency should have had a second examination according to our criteria, only 18.44 persons were actually examined. So a third of subjects were omitted. The air and bone conduction performance rate by each frequency is 75.71 %. 24.29 % persons did not have a bone conduction and were evaluated only by air conduction. The correct use rate of symbols(right, left-unmasked AC, masked AC, unmasked BC, and masked BC) recommended by ASHA(American Speech-Language-Hearing Association) was 70.36 %. Generally air conduction threshold is equal to or higher than bone conduction threshold. In the reverse case, especially if the gap is more than 10 dB(BC-AC > 10), this is considered to be incorrect. When we applied this criteria, the result indicated that it was correct in 75.46 %. The performance rate of air masking was 15.03 %, and bone masking was 26.21 %. 7 among 48 agencies diagnosed NIHL(Noise-Induced Hearing Loss) only by air conduction, 8 performed air masking and 13 did bone masking. When compared with ISO Standard(1964) and Ministry of Labor Standard, the results of evaluation(D1, D2) on hearing loss according to hearing loss type and threshold were rather low. CONCLUSIONS: Hearing Quality Assurance Program about periodic special examination agencies and examiners will continue to be needed and also the evaluation of hearing loss should be performed and controlled using accurate criteria. This will reduce the error among examiners and results in individuals by means of a standard that is capable of being accurate and reliable.
Audiometry, Pure-Tone* ; Bone Conduction ; Hearing ; Hearing Loss ; Humans ; Masks ; Mass Screening ; Noise