[Which colours can we hear?: light stimulation of the hearing system]. / Welche Farben könnten wir hören?: Lichtstimulation des Hörsystems.

The success of conventional hearing aids and electrical auditory prostheses for hearing impaired patients is still limited in noisy environments and for sounds more complex than speech (e. g. music). This is partially due to the difficulty of frequency-specific activation of the auditory system using these devices. Stimulation of the auditory system using light pulses represents an alternative to mechanical and electrical stimulation. Light is a source of energy that can be very exactly focused and applied with little scattering, thus offering perspectives for optimal activation of the auditory system. Studies investigating light stimulation of sectors along the auditory pathway have shown stimulation of the auditory system is possible using light pulses. However, further studies and developments are needed before a new generation of light stimulation-based auditory prostheses can be made available for clinical application.

Optoacoustic induced vibrations within the inner ear.

An acoustic transient can be generated inside an absorbing tissue as a result of laser-tissue interaction after pulsed laser irradiation. Herein we report a novel application of this physical process, the optoacoustic wave generation in the inner ear and subsequently the induction of basilar membrane vibrations. These laser induced vibrations show a direct correlation to the laser energy and an indirect correlation to the distance from the irradiation focus. Through these characteristics they may be used, in a new generation of cochlear implants, to improve the frequency specific cochlear activation and consequently improve speech perception in hearing impaired patients with residual hearing.

[Unusually long latency before the appearance of Frey's syndrome after parotidectomy]. / Aussergewöhnlich lange Latenz für das Auftreten des Frey-Syndroms nach Parotidektomie.

We report on an unusual case of Frey's syndrome. A 45 year old male patient presented with gustatory sweating 14 years after parotidectomy. The sialography showed a post-parotidectomy status without any pathologic findings. The MRI also showed a normal rest-parenchyma of the parotid gland without any pathologic findings. Minor's starch iodine test [14], confirmed the gustatory sweating in the left preauricular area. Frey's syndrome can appear with a latency of 14 years postoperative or post-trauma. The pathogenic mechanism and the curative therapy for this auriculotemporal-syndrome are still unsolved.