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- Håkansson, Bo, 1953, et al.
(författare)
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Percutaneous Versus Transcutaneous Bone Conduction Implant System : A Feasibility Study on a Cadaver Head
- 2008
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Ingår i: Otology and Neurotology. - 1531-7129 .- 1537-4505. ; 29:8, s. 1132-1139
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Percutaneous bone-anchored hearing aid (BAHA) is an important rehabilitation alternative for patients who have conductive or mixed hearing loss. However, these devices use a percutaneous and bone-anchored implant that has some drawbacks reported. A transcutaneous bone conduction implant system (BCI) is proposed as an alternative to the percutaneous system because it leaves the skin intact. The BCI transmits the signal to a permanently implanted transducer with an induction loop system through the intact skin. The aim of this study was to compare the electroacoustic performance of the BAHA Classic-300 with a full-scale BCI on a cadaver head in a sound field. The BCI comprised the audio processor of the vibrant sound bridge connected to a balanced vibration transducer (balanced electromagnetic separation transducer).Methods: Implants with snap abutments were placed in the parietal bone (Classic-300) and 15-mm deep in the temporal bone (BCI). The vibration responses at the ipsilateral and contralateral cochlear promontories were measured with a laser Doppler vibrometer, with the beam aimed through the ear canal.Results: Results show that the BCI produces approximately 5 dB higher maximum output level and has a slightly lower distortion than the Classic-300 at the ipsilateral promontorium at speech frequencies. At the contralateral promontorium, the maximum output level was considerably lower for the BCI than for the Classic-300 except in the 1-2 kHz range, where it was similar.Conclusion: Present results support the proposal that a BCI system can be a realistic alternative to a BAHA.
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| 2. |
- Reinfeldt, Sabine, 1978, et al.
(författare)
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Examination of bone-conducted transmission from sound field excitation measured by thresholds, ear-canal sound pressure, and skull vibrations
- 2007
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Ingår i: Journal of the Acoustical Society of America. - : Acoustical Society of America (ASA). - 1520-8524 .- 0001-4966. ; 121:3, s. 1576-1587
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Tidskriftsartikel (refereegranskat)abstract
- Bone conduction (BC) relative to air conduction (AC) sound field sensitivity is here defined as the perceived difference between a sound field transmitted to the ear by BC and by AC. Previous investigations of BC-AC sound field sensitivity have used different estimation methods and report estimates that vary by up to 20 dB at some frequencies. In this study, the BC-AC sound field sensitivity was investigated by hearing threshold shifts, ear canal sound pressure measurements, and skull bone vibrations measured with an accelerometer. The vibration measurement produced valid estimates at 400 Hz and below, the threshold shifts produced valid estimates at 500 Hz and above, while the ear canal sound pressure measurements were found erroneous for estimating the BC-AC sound field sensitivity. The BC-AC sound field sensitivity is proposed, by combining the present result with others, as frequency independent at 50 to 60 dB at frequencies up to 900 Hz. At higher frequencies, it is frequency dependent with minima of 40 to 50 dB; at 2 and 8 kHz, and a maximum of 50 to 60 dB at 4 kHz. The BC-AC sound field sensitivity is the theoretical limit of maximum attenuation achievable with ordinary hearing protection devices. (c) 2007 Acoustical Society of America.
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