HUMAN SPEECH.

Thames Star, Volume IX, Issue 3024, 24 October 1878, Page 4

HUMAN SPEECH.

The Royal United Service Institution was recently crowded from floor to ceiling in acceptation of a promise on the part of Mr W. JH. Preece, vice-president of the Society of Telegraph Engineers, to lecture on the interesting subject of the transmission and reproduction of human speech, with exhibits of the phonograph and microphone. Admiral Sir F. Nicholson, who presided, announced that Mr Preece was too ill to attend, and that Dr. Mann, at a very short notice, had kindly supplied his place. Dr Mann, who was, received with warm applause, explained that the apparatus was, that of Mr Preece, and that his own part would be merely to supply the illustrations. Proceeding to describe the action of waves of sound, Dr Mann borrowed from Professor Tyndall's opening lecture on the same subject the illustration of five boy 8 standing in a row, one with, the hand on the other's shoulder, a position in which an impetus given to one would be felt by all, and especially by the last, who, having nothing to support him, would reel, and if standing on the edge of a gulf would fall over, or if against a window would break' it, or if against a drum would produce vibration. Sound acted on the molecules of the air as the push on the first boy, causing a vibration on these minute particles until they communicated the vibration to a drum of the >ear. Sound he described as vibratory taps upon the organ of the ear, and from this point he proceeded to describe that organ, as well as the organs of speech, showing how by the organs of speech various sounds were produced, and how they were received by the ear. The phonograph he described as a mechanical means of reproducing these sounds, and he proceeded in detail, by means of drawings on the wall, to show how the sounds were transmitted by means of the little notch on a cylinder to the tinfoil, and reproduced by the little machine being reversed. A nursery rhyme was chanted by M. Stroh, whose improved instrument was exhibited, and the voice was loudly echoed back, every expression being, too, like a person speaking through a tube. The song was repeated, and with exactly the same results. A lady was invited to join a gentleman in singing "God Save the Queen," but, as no lady would volunteer, the duty was undertaken by M. Stroh and a gentleman, arid both voices could be heard when the phonograph was reversed. The lecturer proceeded then to describe the microphone, and stated that this instrument, which magnifies sound as a microscope magnifies material, was invented by Professor Hughes after long investigation, and was not stumbled upon, bnt was the result of long enquiry. The apparatus in this case is electrical, the microphone, to speak of it in a few words, being a chamber which constitutes a break in an electric circuit, and the sound being there concentrated is sent forth in an increased volume. By the aid of a telephone the sounds of the ticking of a watch, of the rustling of pieces of paper, and of flies walking in a match-box were conveyed to the ears of the audience, who could not otherwise have known that such sounds had broken upon the air. DrMann stated that this little instrument was only in its infancy, but would be of incalculable service in medicine and surgery for the discovery and treatment of disease, as by it could be heard the delicate sounds in the ; animal economy otherwise not distinguishable by the ear aided by the instruments now in use. Thanks were cordially voted to Dr Mann for his lecture.—Times.