Besides investigating the function of a new implantable bone conduction hearing aid, Sabine Reinfeldt has studied the sensitivity for bone conducted sound and also examined the possibilities for a two-way communication system that is utilizing bone conduction in noisy environments.
A new Bone Conduction Implant (BCI) hearing system was investigated by Sabine Reinfeldt:
"This hearing aid does not require a permanent skin penetration, in contrast to the Bone-Anchored Hearing Aids (BAHAs) used today."
Measurements showed that the new BCI hearing system can be a realistic alternative to the BAHA.
Sound is normally perceived through Air Conduction (AC), which means that the sound waves in the air enter the ear-canal and are transmitted to the cochlea in the inner ear. However, sound can also be perceived via Bone Conduction (BC). Vibrations are then transmitted to the cochleae through the skull bone from either one's own voice, the surrounding sound field, or a BC transducer.
In two-way communication systems, BC is believed to improve the sound quality when used in extremely noisy environments which require hearing protection devices in the ear-canals.
Several studies were performed to investigate the possibilities for a BC communication system and to increase the general knowledge of BC sound perception.
The low-frequency increase in perceived BC sound when wearing ear-plugs and/or ear-muffs is called the occlusion effect. This effect was studied by different methods and it was found that it is lower for deeper insertion of ear-plugs and for larger ear-muffs, and that it varies for different stimulations.
The difference in sensitivity of the BC and AC parts of one's own voice was estimated, showing that the BC component dominated for most sounds between 1 and 2 kHz. To be able to measure the BC component of a person's own voice, a large ear-muff was developed to attenuate the AC sound and to minimize the occlusion effect.
The study also showed that the sensitivity difference between the BC and AC parts of one's own voice were different for different kinds of sounds, depending on where in the mouth the sound is produced and on the influence from the vocal cords.
Also estimated was the difference in sensitivity between BC and AC sound from a surrounding sound field, demonstrating that the BC part was 40 to 60 dB lower than the AC part. This measure gives the maximum attenuation achievable with ordinary hearing protection devices, like ear-plugs and ear-muffs. It also shows the possible noise reduction from the surrounding noise by using a BC microphone, instead of an ordinary AC microphone in front of the mouth, to record one's own voice in a noisy environment.
Moreover, the amount of BC sound reaching the cochleae from different positions of the skull bone was examined with the conclusion that relative BC hearing can be estimated from ear-canal sound pressure and cochlear vibrations.
The thesis "Bone Conduction Hearing in Human Communication - Sensitivity, Transmission, and Applications" was defended in public on June 5, 2009.More information:
Further reports about: > BAHA > BCI > Bone Conduction Implant > Bone-Anchored Hearing Aids > Technology > bone conducted sound > communication system > conduction > ear-canals > hearing > implantable bone conduction > noisy environments > permanent skin penetration > two-way communication system > vibrations
New Technologies for A/V Analysis and Search
13.04.2017 | Fraunhofer-Institut für Digitale Medientechnologie IDMT
On patrol in social networks
25.01.2017 | Fraunhofer-Institut für Arbeitswirtschaft und Organisation IAO
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems Holding GmbH about commercial use of a multi-well tissue plate for automated and reliable tissue engineering & drug testing.
MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems...
Pathogenic bacteria are becoming resistant to common antibiotics to an ever increasing degree. One of the most difficult germs is Pseudomonas aeruginosa, a...
Scientists from the MPI for Chemical Energy Conversion report in the first issue of the new journal JOULE.
Cell Press has just released the first issue of Joule, a new journal dedicated to sustainable energy research. In this issue James Birrell, Olaf Rüdiger,...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
19.09.2017 | Event News
19.09.2017 | Physics and Astronomy
19.09.2017 | Power and Electrical Engineering