The EarLens system: New sound transduction methods
| Autor: | Micha Rosen, Rodney C. Perkins, Jonathan P. Fay, Lisa Olson, Paul Rucker, Sunil Puria |
|---|---|
| Rok vydání: | 2010 |
| Předmět: |
Hearing aid
Time Factors Tympanic Membrane Optical Phenomena Gain before feedback Microphone Hearing Loss Sensorineural Acoustics medicine.medical_treatment Transducers Population Vibration Article Electromagnetic Fields Hearing Aids Audiometry Feedback Sensory Pressure otorhinolaryngologic diseases medicine Humans Ear External education Physics education.field_of_study Optical Devices Auditory Threshold Equipment Design Sensory Systems Transducer medicine.anatomical_structure Acoustic Impedance Tests Hearing level Electromagnetic coil Speech Perception sense organs Noise Eardrum |
| Zdroj: | Hearing Research. 263:104-113 |
| ISSN: | 0378-5955 |
| Popis: | The hypothesis is tested that an open-canal hearing device, with a microphone in the ear canal, can be designed to provide amplification over a wide bandwidth and without acoustic feedback. In the design under consideration, a transducer consisting of a thin silicone platform with an embedded magnet is placed directly on the tympanic membrane. Sound picked up by a microphone in the ear canal, including sound-localization cues thought to be useful for speech perception in noisy environments, is processed and amplified, and then used to drive a coil near the tympanic-membrane transducer. The perception of sound results from the vibration of the transducer in response the electromagnetic field produced by the coil. Sixteen subjects (ranging from normal-hearing to moderately hearing-impaired) wore this transducer for up to a 10-month period, and were monitored for any adverse reactions. Three key functional characteristics were measured: (1) the maximum equivalent pressure output (MEPO) of the transducer; (2) the feedback gain margin (GM), which describes the maximum allowable gain before feedback occurs; and (3) the tympanic-membrane damping effect (D(TM)), which describes the change in hearing level due to placement of the transducer on the eardrum. Results indicate that the tympanic-membrane transducer remains in place and is well tolerated. The system can produce sufficient output to reach threshold for those with as much as 60 dBHL of hearing impairment for up to 8 kHz in 86% of the study population, and up to 11.2 kHz in 50% of the population. The feedback gain margin is on average 30 dB except at the ear-canal resonance frequencies of 3 and 9 kHz, where the average was reduced to 12 dB and 23 dB, respectively. The average value of D(TM) is close to 0 dB everywhere except in the 2-4 kHz range, where it peaks at 8dB. A new alternative system that uses photonic energy to transmit both the signal and power to a photodiode and micro-actuator on an EarLens platform is also described. |
| Databáze: | OpenAIRE |
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