• Journal of Audiology & Otology
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• v.24 no.2
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• pp.79-84
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• 2020

Background and Objectives: Hearing can be elicited in response to vibratory stimuli delivered to fluid in the external auditory meatus. To obtain a complete audiogram in subjects with normal hearing in response to pure tone vibratory stimuli delivered to fluid applied to the external meatus. Subjects and Methods: Pure tone vibratory stimuli in the audiometric range from 0.25 to 6.0 kHz were delivered to fluid applied to the external meatus of eight participants with normal hearing (15 dB or better) using a rod attached to a standard clinical bone vibrator. The fluid thresholds obtained were compared to the air conduction (AC), bone conduction (BC; mastoid), and soft tissue conduction (STC; neck) thresholds in the same subjects. Results: Fluid stimulation thresholds were obtained at every frequency in each subject. The fluid and STC (neck) audiograms sloped down at higher frequencies, while the AC and BC audiograms were flat. It is likely that the fluid stimulation audiograms did not involve AC mechanisms or even, possibly, osseous BC mechanisms. Conclusions: The thresholds elicited in response to the fluid in the meatus likely reflect a form of STC and may result from excitation of the inner ear by the vibrations induced in the fluid. The sloping fluid audiograms may reflect transmission pathways that are less effective at higher frequencies.

• Korean Journal of Audiology
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• v.24 no.2
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• pp.79-84
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• 2020

Background and Objectives: Hearing can be elicited in response to vibratory stimuli delivered to fluid in the external auditory meatus. To obtain a complete audiogram in subjects with normal hearing in response to pure tone vibratory stimuli delivered to fluid applied to the external meatus. Subjects and Methods: Pure tone vibratory stimuli in the audiometric range from 0.25 to 6.0 kHz were delivered to fluid applied to the external meatus of eight participants with normal hearing (15 dB or better) using a rod attached to a standard clinical bone vibrator. The fluid thresholds obtained were compared to the air conduction (AC), bone conduction (BC; mastoid), and soft tissue conduction (STC; neck) thresholds in the same subjects. Results: Fluid stimulation thresholds were obtained at every frequency in each subject. The fluid and STC (neck) audiograms sloped down at higher frequencies, while the AC and BC audiograms were flat. It is likely that the fluid stimulation audiograms did not involve AC mechanisms or even, possibly, osseous BC mechanisms. Conclusions: The thresholds elicited in response to the fluid in the meatus likely reflect a form of STC and may result from excitation of the inner ear by the vibrations induced in the fluid. The sloping fluid audiograms may reflect transmission pathways that are less effective at higher frequencies.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1820-1825
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• 2005

DSP chip parameters of a digital hearing aid (HA) should be optimally selected or fitted for hearing impaired persons. The more precise parameter fitting guarantees the better compensation of the hearing loss (HL). Digital HAs adopt DSP chips for more precise fitting of various HL threshold curve patterns. A specific DSP chip such as Gennum GB3211 was designed and manufactured in order to match up to about 4.7 billion different possible HL cases with combination of 7 limited parameters. This paper deals with a digital HA fitting program which is developed for optimal fitting of GB3211 DSP chip parameters. The fitting program has completed features from audiogram input to DSP chip interface. The compensation effects of the microphone and the receiver are also included. The paper shows some application examples.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.6
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• pp.530-538
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• 2006

DSP chip parameters of a digital hearing aid (HA) should be optimally selected or fitted for hearing impaired persons. The more precise parameter fitting guarantees the better compensation of the hearing loss (HL). Digital HAs adopt DSP chips for more precise fitting of various HL threshold curve patterns. A specific DSP chip such as Gennum GB3211 was designed and manufactured in order to match up to about 4.7 billion different possible HL cases with combination of 7 limited parameters. This paper deals with a digital HA fitting program which is developed for optimal fitting of GB3211 DSP chip parameters. The fitting program has completed features from audiogram input to DSP chip interface. The compensation effects of the microphone and the receiver are also included. The paper shows some application examples.

• Journal of Biomedical Engineering Research
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• v.16 no.1
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• pp.77-84
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• 1995

Nl and N2 gross neural action potentials were measured from the round window of the guinea pig cochlea at the onset of the acoustic stimuli. Nl -N2 audiograms were made by means of regulating stimulant intensities in order to produce constant Nl -N2 potentials as criteria for different input tone pip frequencies. The lowest threshold was measured with an input tone pip 15 dB SPL in intensity and 12 KHz in frequency when the animal was in normal physiological condition. The procedure of experimental measurements is explained in detail. This experimental approach is very useful for the investigation of the Cochlear function. Both nonlinear and active functions of the Cochlea can be monitored by Nl -N2 audiograms. Key words : Guinea Pig, Cochlea, Wl and N2 Gross Neural Action Potential, Nl -N2 audiogram.

• Journal of Audiology & Otology
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• v.25 no.3
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• pp.159-162
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• 2021

Temporal bone trauma can cause hearing loss and in case of prolonged conductive hearing loss, traumatic ossicular injury should be considered. Separation of the incudostapedial joint is the most common lesion, and stapediovestibular dislocation is relatively rare but can easily cause perilymphatic fistula. Here, we report a very rare case of external stapediovestibular dislocation after trauma, ending up with successful surgical outcome. A 27-year-old man with non-progressive hearing loss on the right side since childhood visited the clinic. Audiogram showed a conductive hearing loss with air-bone gap of 55 dB on the right side. Temporal bone CT revealed the disruption of ossicular chain. An exploratory tympanotomy identified multiple ossicular disruptions including external stapediovestibular dislocation with shiny fibrous membrane sealing the oval window. Ossicular chain reconstruction was performed using the total ossicular replacement prosthesis of titanium. A postoperative audiogram showed a recovery of air-bone gap less than 10 dB. To the best of our knowledge, this is the first case of external long-standing stapediovestibular dislocation, with oval window completely sealed with fibrous membrane, ending up with successful hearing recovery by surgery. This case would help dealing with such condition which can be encountered in the clinic.

• Journal of Audiology & Otology
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• v.24 no.3
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• pp.127-132
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• 2020

Background and Objectives: In this study, we compared the outcomes of patients with idiopathic sudden sensorineural hearing loss who underwent steroid treatment with or without hyperbaric oxygen (HBO) therapy and were followed-up in our clinic. Subjects and Methods: Patients were divided into two groups according to their treatment regimen. Steroid group received intravenous 1 mg/kg methylprednisolone which was due to be completed in 2-3 weeks with decreasing doses, and five doses of 0.5 mL intratympanic dexamethasone. Steroid+HBO group received the same steroid treatment with the addition of HBO therapy. The audiologic results of both treatment groups were compared after considering the patients' risk factors. Results: There was no significant difference between the steroid and Steroid+HBO groups in terms of hearing gain and degree of recovery, both at all degrees of hearing loss, and in severe and profound hearing loss. Hearing gain was similar when evaluated by audiogram type and admission time in both treatment groups. Conclusions: We found that the addition of HBO therapy to systemic plus intratympanic steroid treatment did not affect hearing gain at all degrees of hearing loss in this study. Furthermore, audiogram type and admission time did not affect hearing gain between the two groups.

• Korean Journal of Audiology
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• v.25 no.3
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• pp.159-162
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• 2021

Temporal bone trauma can cause hearing loss and in case of prolonged conductive hearing loss, traumatic ossicular injury should be considered. Separation of the incudostapedial joint is the most common lesion, and stapediovestibular dislocation is relatively rare but can easily cause perilymphatic fistula. Here, we report a very rare case of external stapediovestibular dislocation after trauma, ending up with successful surgical outcome. A 27-year-old man with non-progressive hearing loss on the right side since childhood visited the clinic. Audiogram showed a conductive hearing loss with air-bone gap of 55 dB on the right side. Temporal bone CT revealed the disruption of ossicular chain. An exploratory tympanotomy identified multiple ossicular disruptions including external stapediovestibular dislocation with shiny fibrous membrane sealing the oval window. Ossicular chain reconstruction was performed using the total ossicular replacement prosthesis of titanium. A postoperative audiogram showed a recovery of air-bone gap less than 10 dB. To the best of our knowledge, this is the first case of external long-standing stapediovestibular dislocation, with oval window completely sealed with fibrous membrane, ending up with successful hearing recovery by surgery. This case would help dealing with such condition which can be encountered in the clinic.

• Korean Journal of Audiology
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• v.24 no.3
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• pp.127-132
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• 2020

Background and Objectives: In this study, we compared the outcomes of patients with idiopathic sudden sensorineural hearing loss who underwent steroid treatment with or without hyperbaric oxygen (HBO) therapy and were followed-up in our clinic. Subjects and Methods: Patients were divided into two groups according to their treatment regimen. Steroid group received intravenous 1 mg/kg methylprednisolone which was due to be completed in 2-3 weeks with decreasing doses, and five doses of 0.5 mL intratympanic dexamethasone. Steroid+HBO group received the same steroid treatment with the addition of HBO therapy. The audiologic results of both treatment groups were compared after considering the patients' risk factors. Results: There was no significant difference between the steroid and Steroid+HBO groups in terms of hearing gain and degree of recovery, both at all degrees of hearing loss, and in severe and profound hearing loss. Hearing gain was similar when evaluated by audiogram type and admission time in both treatment groups. Conclusions: We found that the addition of HBO therapy to systemic plus intratympanic steroid treatment did not affect hearing gain at all degrees of hearing loss in this study. Furthermore, audiogram type and admission time did not affect hearing gain between the two groups.

• 대한예방의학회:학술대회논문집
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• 2002.10a
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• pp.586-587
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• 2002