LASERHEARINGAIDS · Laser: driving force for a new generation of hearing aids

This proposal presents an unconventional method for the stimulation of the outer and middle ear that may change the current concept of hearing aids. Photons of the visible light are known to activate the visual sensory cells through photoreceptors. However, when the so-called stress-confinement condition is fulfilled, laser light can induce an acoustic signal through an optoacoustic effect. We demonstrated previously that these light induced sound waves, the optoacoustic waves, can be used to activate the inner ear, the cochlea. Unexpectedly, we found that not just the inner ear but also the middle and outer ear are responsive to laser pulses. However, simple activation of the auditory system is not a sufficient therapy in hearing impaired people. A controlled frequency specific activation of the complete audible frequency spectrum is mandatory to make speech and complex sounds of daily life perceptible and intelligible. The overall objective of this project is to establish methods for frequency specific activation of the complete audible spectrum using monochrome laser pulses. The frequency modulation is a well known process in physics that has to be proven as valid for biological systems as well. Successfull development of parameters for frequency modulation and speech coding resulting will create / provide the basis for a novel non-contact stimulation method that will revolutionize the implantable and non-implantable hearing aids by replacing the speaker or the sound transducer (force mass transducer, the Bone Anchored Hearing Aid screw) with the non contact and focused laser pulses. We expect that the development of these novel stimulation-strategy and stimulation-devices will ameliorate patients’ quality of life by significantly improving their aided hearing and comfort using the hearing device as well as reducing medical health care expenses determined through device related complications.