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- Dobrev, Ivo, et al.
(författare)
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Influence of stimulation position on the sensitivity for bone conduction hearing aids without skin penetration
- 2016
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Ingår i: International Journal of Audiology. - : TAYLOR & FRANCIS LTD. - 1499-2027 .- 1708-8186. ; 55:8, s. 439-446
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Tidskriftsartikel (refereegranskat)abstract
- Objective: This study explores the influence of stimulation position on bone conduction (BC) hearing sensitivity with a BC transducer attached using a headband. Design:(1) The cochlear promontory motion was measured in cadaver heads using laser Doppler vibrometry while seven different positions around the pinna were stimulated using a bone anchored hearing aid transducer attached using a headband. (2) The BC hearing thresholds were measured in human subjects, with the bone vibrator Radioear B71 attached to the same seven stimulation positions. Study sample: Three cadaver heads and twenty participants. Results: Stimulation on a position superior-anterior to the pinna generated the largest promontory motion and the lowest BC thresholds. Stimulations on the positions superior to the pinna, the mastoid, and posterior-inferior to the pinna showed similar magnitudes of promontory motion and similar levels of BC thresholds. Conclusion: Stimulations on the regions superior to the pinna, the mastoid, and posterior-inferior to the pinna provide stable BC transmission, and are insensitive to small changes of the stimulation position. Therefore it is reliable to use the mastoid to determine BC thresholds in clinical audiometry. However, stimulation on a position superior-anterior to the pinna provides more efficient BC transmission than stimulation on the mastoid.
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| 2. |
- Roosli, Christof, et al.
(författare)
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Intracranial Pressure and Promontory Vibration With Soft Tissue Stimulation in Cadaveric Human Whole Heads
- 2016
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Ingår i: Otology and Neurotology. - : LIPPINCOTT WILLIAMS & WILKINS. - 1531-7129 .- 1537-4505. ; 37:9, s. E384-E390
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Tidskriftsartikel (refereegranskat)abstract
- Hypothesis:Intracranial pressure and skull vibrations are correlated and depend on the stimulation position and frequency.Background:A hearing sensation can be elicited by vibratory stimulation on the skin covered skull, or by stimulation on soft tissue such as the neck. It is not fully understood whether different stimulation sites induce the skull vibrations responsible for the perception or whether other transmission pathways are dominant. The aim of this study was to assess the correlation between intracranial pressure and skull vibration measured on the promontory for stimulation to different sites on the head.Methods:Measurements were performed on four human cadaver heads. A bone conduction hearing aid was held in place with a 5-Newton steel headband at four locations (mastoid, forehead, eye, and neck). While stimulating in the frequency range of 0.3 to 10kHz, acceleration of the cochlear promontory was measured with a Laser Doppler Vibrometer, and intracranial pressure at the center of the head with a hydrophone.Results:Promontory acceleration and intracranial pressure was measurable for all stimulation sites. The ratios were comparable between all stimulation sites for frequencies below 2kHz.Conclusion:These findings indicate that both promontory acceleration and intracranial pressure are involved for stimulation on the sites investigated. The transmission pathway of sound energy is comparable for the four stimulation sites.
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