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Asthma often remains uncontrolled, despite the fact that the pharmacological treatment has undergone large changes. We studied changes in the treatment of asthma over a 20-year period and identified factors associated with the regular use of inhaled corticosteroid (ICS) treatment. Changes in the use of medication were determined in 4617 randomly selected subjects, while changes in adults with persistent asthma were analysed in 369 participants. The study compares data from three surveys in 24 centres in 11 countries. The use of ICSs increased from 1.7% to 5.9% in the general population and the regular use of ICSs increased from 19% to 34% among persistent asthmatic subjects. The proportion of asthmatic subjects reporting asthma attacks in the last 12 months decreased, while the proportion that had seen a doctor in the last 12 months remained unchanged (42%). Subjects with asthma who had experienced attacks or had seen a doctor were more likely to use ICSs on a regular basis. Although ICS use has increased, only one-third of subjects with persistent asthma take ICSs on a regular basis. Less than half had seen a doctor during the last year. This indicates that underuse of ICSs and lack of regular healthcare contacts remains a problem in the management of asthma., Despite increased ICS use, only 34% of subjects with persistent asthma take ICSs on a regular basis

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. Human cortical evoked potentials represent rhythm, consonance, and (as DC-shift) the emotional content of music. Marked harmonics, even of single hair-cell vibrations and in single units of medial geniculate in combination with clock-cell networks, are the physiological basis of "harmony" in music. Dissonant stimuli are detectable at the cortical level in man (Finkenzeller, Keidel).

The human cortical potential evoked by a 1000-Hz tone was recorded under conditions of binaural and monaural stimulation which covered a wide range of stimulus intensities. The results showed that (1) the curve for the amplitude as well as for the area confined by the potential increased with increases in stimulus intensity. At higher stimulus intensities, these curves leveled off. (2) Bilateral stimulation generated larger cortical potentials than did monaural stimulation. (3) Latency of the potential decreased with increases in stimulus intensity. When the monaural stimulus was delivered to the ear contralateral to the active scalp electrode, the various components of the potential showed consistently a shorter latency than when the monaural stimulus was presented ipsi-laterally.This research was supported by a grant from the National Institute of Neurological Diseases and Blindness, USA., and the Deutsche Forschungsgemeinschaft.

This morning, during the previous session of this roundtable discussion, we were presented with a good deal of experimentation concerning the possible role of various tonal stimuli in neural discrimination. The problem of periodicity-analysis, at the very least, must be taken into consideration when discussing the over-all frequency analysis of the ear and the problem of pitch.

Der Off-Effekt des akustisch evozierten Potentials weist, verglichen mit dem On-Effekt, eine Amplitude von etwa 25–45% bei ungefilterten Sinustonimpulsen und 35—55% bei weisen Rauschimpulsen auf. Ebenso wie der On-Effekt gehorcht der Off-Effekt einer Intensitatsabhangigkeit, allerdings, vor allem beim Rauschen, mit geringerer Steilheit. Eine signifikante Abhangigkeit der Amplitude des Off-Effektes von der Beschallungsdauer zwischen 300 und 1300 ms konnte nicht nachgewiesen werden. Signifikante Differenzen zwischen einzelnen Versuchspersonen bei Beschallungsdauern von 400 bzw. 500 ms sind wahrscheinlich auf Uberlagerungsvorgange zuruckzufuhren. Vergleichbar mit den Latenzen des On-Effektes zeigen diejenigen des Off-Effektes ebenfalls eine Verkurzung mit steigender Intensitat. Bezogen auf das Schallende sind die Latenzen von Potentialschwankungen vergleichbarer Polaritat am Schallende jedoch wesentlich kurzer. Fur die negative Komponente werden Werte zwischen 40 und 71 ms, fur die positive Komponente Werte zwischen 100 und 140 ms gemessen.

1. Anhand der Literatur wird zuerst die Entwicklung und der heutige Stand der objektive ven Auskultation dargestellt und diskutiert. Da ein kritisches Studium der einschlagigen Literatur des Herz- und Lungenschalls einerseits eine deutliche Grenze zwischen physiologischen und pathologischen Gerauschen furs Herz etwa bei 120–150 Hz, fur den Lungenschall bei etwa 300 Hz erkennen last, andererseits physikalische gesehen nur relativ kleine Frequenzanderungen physiologisch und pathognomonisch wesentlich sind, halt Verfasser die bisher aus der Technik bekannten Schallspektrographen fur Zwecke der Untersuchungn des Herz- und Lungenschalls fur nicht sehr geeignet, weil in der Technik immer ein im Vergleich deazu sehr groser Frequenzbereich untersucht wird, fur den diese Gerate gebaut sind. 2. Es wird daher nach einer Methode gesucht, die den Frequenzbereich zwischen 60 und 600 Hz mit groserer Untersuchiedsempfindlichkeit zu messen gestattet, als es das Ohr vermag. 3. Im zweiten, experimentellen Teil der Arbeit wird sodann eine Methode beschrieben, die nach Ansisch des Verfassers die Forderungen erfullt, die an einen physiologisch begrundeten Frequenzanalysator des Herzund Lungenschalls gestellt werden mussen: Die Indikatordiagraphie des Herz- und Lungenschalls. 4. Die Indikatordiagraphie des Schalls beruht auf der Verwendung eines Zweikanalverstarkers, der speziell nach den Forderungen von Punkt 2 konstruiert ist und in Indikatordarstellung auf dem Schirm einer Braunschen Rohre einen Schallvektor abzubilden gestattet, dessen. Winkel mit der Waagrechten ein Mas fur die zu messende Frequenz ist. 5. Anhand der Darstellung von Indikatordiagrammen von einfachen Sinusschwingungen, des Schalls von Musikinstrumenten, des normalen und pathologischen Herzcschalls, sowie einiger typischer Atemperauscharten wird die Arbeitsweise der beschriebenen Apparatur aufgezeigt. 6. Anhangeweise wird schlieslich das physikalische Grundprinzip der Methode und die Grundform der Indikatordiagramme durchgerechnet. Die Rechnung steht in Ubereinstimmung mit den experimentellen Ergebnissen.

Based upon some experimental work during the last two years wc were able to demonstrate that it is possible to record extracranially a characteristic slowly evoked cortical response of a rather complex nature time locked to auditory stimuli. All potentials are evoked by sinusoidal tones of 1 second duration. They were averaged by means of a special type of physiological computer. It was possible to record clearly intensity-related human cortical responses of medium latency (second negative deflection, latency 150 to 180 msec). Thus a quantitatively reliable correlation with the stimulus parameters was obtained.The late second negative deflection was measured and the results were compared with those of the Stevens group. This part of our cortical responses when plotted double-logarithmically versus intensity clearly showed the identical exponents of Stevens' power functions when stimulating the auditory and the somesthetic system, the latter especially by both vibratory and electric pain eliciting qualitie...

Bei der Anwendung einer objektiven Audiometrie, die auf elektrophysiologischen Messungen am Menschen basiert, bewirkt die Vernachlassigung von Fehlermoglichkeiten das Auftreten einer groseren Streuung der Mesergebnisse. In den vorliegenden Ausfuhrungen werden die verhaltnismasig leicht erkennbaren Fehlerquellen aufgezahlt und diskutiert.

Es wird uber quantitative Ergebnisse bei einohriger Schallreizung mit Registrierung und elektronischer Mittelung der am unverletzten Schadel ableitbaren langsamen Rindenpotentiale (slow evoked potentials) berichtet, die in der Spontanaktivitat des Gehirns normalerweise nicht erkennbar und im EEG deshalb nicht auswertbar sind. Grosse und Zeitgang der menschlichen Rindenpotentiale werden dargestellt und mit den Ergebnissen aus Tierversuchen verglichen. Ein Teilergebnis weist aus, dass im Rahmen der Optimalisierungsfunktion des sensorischen Teils des ZNS des Menschen der Informationsinhalt dieser Potentiale signifikant verschieden ausfallt, je nachdem ob periodische oder statistische Schallreizfolgen einwirken. Dieses neue Verfahren gestattet den quantitativen Vergleich elektrophysiologischer und psychophysischer Messergebnisse bei derselben menschlichen Versuchs-person.

Direct-current (dc) deflections in the EEG in response to sensory stimuli were first described by Kohler 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. By this means, all types of electric responses obtainable from the intact human skull so auditory, gustatory and olfactory stimuli can be plotted simultaneously including the dc shift duirng a relatively long-lasting train of clicks (perstimulatory dc shift). This technique has been applied both in normal and in pathological subjects in various hospitals (ENT and children's clinics, in our country. The results obtained using this technique are described in our contribution.

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. Decompression of intensity range and compression of frequency range might be especially useful.

In the chapter written by Professor Hallowell Davis the clinical use of ERA (Electric Response Audiometry) in audiology is described in full detail including the early response (BERA) and the perstimulatory DC-shift. Hence, this most important subtopic of the auditory evoked responses can be omitted here. We therefore feel that our contribution in this handbook should deal with all those questions and solutions — as far as they have been elaborated — which are related to explanations from a neurophysiological background. Thus, it should be obvious that a response as complex as the auditory evoked potential must be looked at under a great variety of aspects. Even then our present knowledge does not allow us to get more than a feeling about possible avenues of the basic physiological principles involved.

The present paper dealt with auditory evoked responses, especially with their temporal and local aspect, according to the criteria of von Kries. It further discussed the problem of specificity and, finally, reported on a novel technique for registering a dc-potential in response to, and during the course of, long-lasting sound signals. Possible applications of this technique and its importance for objective audiometry are being discussed.