"The Auraphone.  Edison's Very Latest--Extraordinary Development of the Phonograph," New York Star, reprinted Indianapolis News, May 21, 1878.

Parties who have personally inspected and listened to the "talking machine" will recall the metallic hoarseness of tones as well as a slight falling off in the volume of its utterances.  Many attribute this to the use of a tin trumpet in delivering the sound, and experiments have since shown this supposition to have been correct.  Long ago Mr. Edison had realized the necessity of utilizing some other and less defective medium, more sensitive and less resonant in material and construction.   After many failures he succeeded in supplying this want by constructing a delivery horn out of a new substance, compounded mainly of catchouc, gelatine and the sensitive carbon which enters so largely into Mr. Edison's manufactures.  A modification was also made on its shape and construction, more especially adapting it to the needed purposes.  Upon the very first time it was found to be almost perfect in action, repeating the voice with such absolute fidelity in tone and inflection as to actually startle the experimenters themselves.  Upon the subsequent day, while again testing its merits, the tube portion of the trumpet accidentally became twisted, when the ever-watchful ear of the inventor at once detected an increase of volume of sound.   His attention was at once directed to the economy of the convolution of the human ear, and the problem presented itself as to whether they do not embody a mechanical principal.  It was not long before this secret yielded itself to the prying search of the wonderful inventor, who discovered that by curling the neck or pipe of the trumpet in a peculiar way and by adding to its convolutions, the faintest sound-wave could be made to recall itself through the medium of the diaphragm, upon the receptive plate or matrix, as deeply as the loudest tone uttered under ordinary conditions.  In short, he succeeded in demonstrating the fact absolutely that by means of proper mechanical arrangements the volume of sound capable of being emitted by the phonograph was actually limitless, and entirely independent of the application of steam, air, valves or any extraneous force.

Impressed with the value of both these discoveries, it was natural in Mr. Edison to set about combining the two, a result he accomplished with little difficulty, the operation of which is to be witnessed at his laboratory in Menlo park, and which he has named the "Auraphone."

The new invention of Edison's is briefly described as follows: in the ceiling of his private office, concealed from view with the exception of a small ear-shaped tunnel [sic, funnel?] of dark color, he has fitted between the rafters and the floor above one of his double-recording and speaking machines.  In the room above a portion of the machine rises through the floor, and attached to it is a small wooden box said to contain the coils of the pipe of the trumpet, the bell or mouth of which opens through one side, and is made of the new substance discovered by Mr. Edison, and is alluded to elsewhere.   With the exception of the box, all other portions of the machine are open to inspection.  Every word uttered in the room below is repeated in the room above with about treble or quadruple the volume of sound (although it can be arranged in vast excess of this), while at the same time it is being recorded on the matrix plate for future references and preservation through the electrotyping process.  The effect produced by the auraphone is not only comically weird but in many ways alarming.  Sending an assistant to the room below in order to test its capacity for catching whispers, the orator, directed by Mr. Edison, bent down his ear to the little box only to be deafened by the inquiry, "What do you think of the auraphone?" shouted in tones that almost made the house rock, followed by a laugh so mockingly hideous and unearthly as to make the blood curdle with terror.  This we soon learned to be one of the peculiar jokes incidental to an introduction of the auraphone, always hugely enjoyed by the inventor and his attaches.  Subsequent experiments proved the exquisite sensitiveness of the machine.  The faintest whisper, the ticking of a clock, the rolling of a lead pencil over the desk, the tearing of a small piece of newspaper, a sigh, a tune hummed in the lowest register--all were successively delivered in the room above in exaggerated volume.   At night, when the quiet is more profound, Mr. Edison informed us that he could plainly hear the purring of his cat in the office below.

The effects to be produced by the introduction of the auraphone will be wonderful.  When all walls have ears, literally, what is to become of our confidence?   With the spy ever in wait for us, not only to repeat them, but to also manufacture their indisputable proof for translation and preservation, what are we to do?  Will society become thoroughly honest, virtuous and good?  Or will it be torn asunder by dissension and relegated by savagery?  When a man's sins are popping up in judgment at all times and places; when a man is forced to go through the world with a window, as it were, in his bosom, will it longer be a pleasant or even an endurable place to live in?   And yet to face this actual contingency we are brought by Mr. Edison and his new auraphone.