unbekannt (unknown)
«telephone concert»

«One of the most popular attractions at the Paris Electrical Exhibition is the nightly demonstration of the marvelous powers of the Ader telephone, by its transmission of the singing on the stage and the music in the orchestra of the Grand Opera at Paris, to a suite of four rooms reserved for the purpose in one of the galleries of the Palais de l'Industrie. This demonstration is given nightly between eight and eleven o'clock, and the enormous number of people who crowd the entrance to the building before the doors are open to the evening visitors rapidly resolve themselves into patient queues as soon as they can obtain access to the gallery adjoining the telephone rooms. There they patiently await their time for admission, and the privilege of hearing for a few minutes whatever may be going on at the opera—solo, chorus, instrumental music, or possibly all three, until the allotted time has expired, and the listeners have to give way for a fresh installment from the outside. In this way eighty telephones are constantly at work at the same time, at short intervals the communication being shifted to another set of eighty similar instruments in two other rooms. [...]
M. Hospitaller, in the article from which we are drawing our information, refers to a peculiar property of the Ader telephone which we cannot do better than deal with in his own words: «We will now consider the new acoustic effect which Mr. Ader has discovered, and applied for the first time in the telephonic transmission at the Electrical Exhibition. Every one who has been fortunate enough to hear the telephones at the Palais de l'Industrie has remarked that, in listening with both ears at the two telephones, the sound takes a special character of relief and localization which a single receiver cannot produce. [...] As soon as the experiment commences the singers place themselves, in the mind of the listener, at a fixed distance, some to the right and others to the left. It is easy to follow their movements, and to indicate exactly, each time that they change their position, the imaginary distance at which they appear to be. This phenomenon is very curious, it approximates to the theory of binauriclar auduition, and has never been applied, we believe, before to produce this remarkable illusion to which may almost be given the name of auditive perspective. [...] Each person is placed in front of a transmitter with two telephones, which receive the impression from two distinct transmitters, placed a certain distance apart. These transmitters are grouped in pairs, 1 and 6, 2 and 7, 3 and 8, 4 and 9, and 5 and 10. Fig. 3 shows the complete arrangement for group 1 and 6. This group supplies sixteen telephones adapted for eight listeners, but the transmitter 1 serves the eight telephones on the left, and the transmitter 6 the eight telephones on the right of the eight listeners, A, B, C, to H.»

(Source: Scientific American, 31.12.1881, pp. 422-423.)