[The phenomenon of hearing: an interdisciplinary discussion. II].

This part of the paper deals with the neurophysiological background of speech analysis and hearing of music. Single vowel- and consonant-detector cells could be clearly separated at the colliculus and geniculate level (Kallert, Keidel). Musical stimulation is decoded at three levels: hair cells, geniculate, and auditory cortex.

[The phenomenon of hearing: an interdisciplinary discourse. I].

For the last century hearing has been considered a purely passive process. G. S.

The computer-vibromyography as a biometric progress in studying muscle function.

Muscular vibrations were recorded from different relaxed and contracted skeletal muscles in human subjects, with the use of a piezo-electric device. Simultaneous wire-EMG recordings were performed. Spectral analysis of the acceleration curves (vibromyograms) disclosed muscle and function dependent compound frequency patterns.

[Determination of two unknown peaks in the 31P magnetic resonance spectrum appearing during the breakdown of high energy phosphates in the ischemic heart and skeletal musculature].

Using the 31-Phosphorus pulsed NMR-technique by FFT information processing it was possible to obtain the following results: The phosphorus compounds were measured as time function in the course of 24 h in isolated skeletal and cardiac muscle of rana temporaria in a dynamic NMR experiment. The shift of the observed resonance lines by increasing intracellular H+ concentration during anoxic conditions will be described in this paper in accordance with the NMR literature. The time course of the beta group of ATP (which is representative for ATP) has been found not to decrease monotonically but rather periodically in a half-hour periodicity until finally a complete fading of ATP in the NMR spectrogram occurs.

[Problems of interpersonal communication in the latter part of life as seen from sensory physiology].

Both, the sensory organs themselves and the central nervous system with its decoding functions for perception of sensory stimuli influence drastically the human ability for social communication especially with respect to the exchange of speech information. Severe hearing loss, e. g.

Late cortical-evoked responses in clinical use.

Direct-current (dc) deflections in the EEG in response to sensory stimuli were first described by Köhler who, however, employed relatively high intensities. Gumnit, as well as Caspers, working with physiological stimulus intensities in animals, and recording from the primary projection areas of the different sensory modalities then showed that the evoked dc potentials during stimulation were restricted to a relatively small area of the animal's cortex which conformed well to the locus of the chosen modality. In our laboratory, using a fully computerized dc recording averaging system with Beckman electrodes, placed normally on the vertex, we have developed a routine technique adapted for clinical use.

Neurophysiological requirements for implanted cochlear prostheses.

In a few introductory remarks the technological, neurophysiological and clinical assessments of new developments in modern, highly sophisticated hearing aids are reviewed. The necessity of preprocessing auditory information is discussed as well as the problems related to the choice of suitable electrodes, and, in particular, how much auditory information for speech communication, given by the product of number of just noticeable differences in intensity, number of just noticeable differences in frequency, number of channels for conveying neurophysiologically processable signals would be required as a minimum for cochlear implants to enable patients to communicate with one another. Finally, the fact that a number of different sensory modalities converge in to man's cortical association area might possibly be used for some special application of a multimodal input in a completely deaf patient with the aim of enabling him to understand human speech.

Neurophysiological requirements for implanted cochlear prostheses.

Regarding the neurophysiological requirements for implanted cochlear prostheses, we have discussed (i) the complexity of speech sounds, (ii) problems of intensity, then (iii) the frequency problem, and (iv) finally the possibility of a frequency transposition to the genuine frequency range of a single fibre of any mechanoreceptor and its connecting nerve fibre (less than 1 kHz) for the construction of an intracochlear prosthesis. In general it would seem necessary to seek compromises based on the fact that speech, at least the vowels, contains redundancy and that the use of additional sensory channels might be helpful for cochlear implants. Certainly besides other preprocessing techniques for speech information, the multichannel stimulation set-up of special electrodes has to be used to convey a sufficient amount of speech information to restore the faculty of speech perception in completely deaf patients.

[The significance of the CNS for the physiology of hearing (author's transl)].

Some general aspects of auditory perception (funnelling, contrast, pattern recognition, form perception, methodological limitations) are discussed in the first part of this presentation. The modern concept of the hydrodynamics of the inner ear, including electronic modelling of the function of the basilar membrane is their dealth with. For the encoding and decoding processes of the auditory system the different grades of intensity function at the different neuronal levels is compared with that of the envelope of the basilar membranes deflection.