Microphone

“ But although a single pencil microphone will under favourable circumstances transmit these varied sounds, the best effect for each kind of sound is obtained by one specially adjusted. There is one pressure best adapted for minute sounds, another for speech, and a third for louder sounds. A simple spring arrangement for adjusting the pressure of the contacts is therefore an advantage, and it can easily be applied to a microphone formed of a small rod of carbon pivoted at its middle, with one end resting on a block or anvil of carbon underneath. ”

“ There are some directions in this play which may be new to you, but these are necessary, for you are now in a radio broadcasting studio, talking in front of a microphone. The word [in] means that the character is standing close to the microphone, while [off] indicates that he is farther away, so that his voice sounds faint. When the directions [off, coming in] are given, the person speaking is away from the microphone at first but gradually comes closer. The words [mob] or [crowd noise] you will understand mean the sound of many people talking in the distance. ”

“ The marvellous fact that a little piece of charcoal can, as it were, both listen and speak, that a person may talk to it so that his friend can hear him at a similar piece a hundred miles away, is a miracle of nineteenth century science which far transcends the oracles of antiquity.
The articulating telephone was the forerunner of the phonograph and microphone, and led to their discovery. They in turn will doubtless lead to other new inventions, which it is now impossible to foresee. ”

“ The Microphone is an instrument that magnifies sound in the same way as a microscope magnifies objects; a very powerful microphone magnifies the sound of a fly walking into a loud tramping footstep, the tick of a watch into a deafening clatter, and a whisper into a loud shout. Take a Microphone, then properly affix it to the Phonograph described above, and you have a good Scolding Machine; turn the handle, and as the Phonograph gives out the scoldings, the microphone part magnifies them so loudly that they are heard for a considerable distance. ”

“ The microphone is a discovery as well as an invention, and the true explanation of its action is as yet merely an hypothesis. It is supposed that the vibrations put the carbons in a tremor and cause them to approach more or less nearly, thus closing or opening the breach between them, which is, as it were, the floodgate of the current. ”

“ Stirrings in the crowd. Mutterings. Temple gaped. Microphone, yes—but receivers also, placed strategically, all around the hall, to pick up sound. Telio receivers too, perhaps? It made him feel something like a goldfish.
Apparently someone liked the idea of the two-way microphones. "I got a question. When are we coming back?"
Laughter. Hooting. Catcalls.
Blared the microphone: "There is a rotation system in operation, men. When it is feasible, men will be rotated." ”

“ It may be here noted that in a paper on experiments in audition published in 1827 Wheatstone said: “The great intensity with which sound is transmitted by solid rods at the same time that its diffusion is prevented, affords a ready means of augmenting the loudness of external sounds and of constructing an instrument which, from its rendering audible the weakest sounds, may with propriety be named the microphone.” ”

“ The discovery of the microphone by Professor Hughes has enabled us to understand the reason of this failure. The transmitter of Reis was based on the plan of interrupting the current, and the spring was intended to close the contact after it had been opened by the shock of a vibration. So long as the sound was a musical tone it proved efficient, for a musical tone is a regular succession of vibrations. ”

“ I tried to get a phonographic record of the whistling; but it simply produced no impression on the wax at all. That is one of the things that has made me feel queer, I can tell you. Another extraordinary thing is that the microphone will not magnify the sound—will not even transmit it; seems to take no account of it, and acts as if it were nonexistent. I am absolutely and utterly stumped, up to the present. I am a wee bit curious to see whether any of your dear clever heads can make daylight of it. ”

“ The sound that is heard in the receiving-instrument of the microphone, when a fly is walking across the board on which the transmitter is placed, is not the sound of the fly's footsteps, any more than the stroke of a powerful electric bell, or sounder, is the magnified sound of the operator's fingers tapping lightly, and it may be inaudibly, upon the key. ”

“ The amount of current flowing in the circuit thus keeps step with the changes in the resistance, and accordingly produces sounds in the telephone receiver. The vibrations emitted from the receiver are usually much greater than those of the original sounds, and so the microphone may be used to magnify weak sounds such as the ticking of clock-wheels or the footfalls of insects. If a watch is laid on the base of the microphone, the ticking of the escapement wheel can be heard with startling loudness. ”

“ The telephone enables us to speak to distances far beyond the reach of eye or ear, 'to waft a sigh from Indus to the Pole; 'the phonograph enables us to seal the living speech on brazen tablets, and store it up for any length of time; while it is the peculiar function of the microphone to let us hear those minute sounds which are below the range of our unassisted powers of hearing. ”

“ In broadcasting a play from a theatre, when the speakers are moving about, the only way of dealing with the problem is to use several microphones and a mixing device which enables the engineer to change silently from one microphone to another, or to combine them in varying proportions. ”

“ In ordinary telephony with connecting wires the current variations are produced by means of a microphone in the transmitter, and in wireless telephony201 the same principle is adopted. Here comes in the outstanding difficulty in wireless transmission of speech. The currents used in ordinary telephony are small, and the microphone works with them quite satisfactorily; but in wireless telephony very heavy currents have to be employed, and so far no microphone has proved capable of dealing effectively with these currents. Countless devices to assist the microphone have been tried. ”

“ The microphone is not only useful as a transmitter of sounds, but also as a relay of sounds received on a telephone. Professors Houston and Thomson of America were perhaps the first to construct a telephonic relay. They mounted a carbon microphone on the vibrating plate of a telephone in such a way that the vibrations of the plate due to the received speech would react on the microphone, and be transmitted in this way over another line to another receiving telephone at a distance. ”

“ It was a burglar's microphone, used for picking combination locks. As the combination turned, a slight sound was made when the proper number came opposite the working point. Imperceptible ordinarily to even the most sensitive ear, to an ear trained it was comparatively easy to recognize the fall of the tumblers over this microphone.
As he worked, the door behind him opened softly and the gray friar entered, closing it and moving noiselessly over back of the shelter of a big mahogany high-boy, around which he could watch. ”

“ In order to hear faint whispers, move the slide-bar away from the carbon block.
In order to hear a fly walk it is necessary to have the carbons very dry and clean. The instrument must be very carefully adjusted. Cover the microphone with a large glass globe and place a fly inside of the globe. Whenever the fly walks on any part of the microphone you will be able to hear each footstep in the telephone receivers. When he flies about inside of the globe, his wings will cause a loud roaring and buzzing noise to be heard in the receivers. ”

“ Another way of observing these curious little movements is by burying microphones in the ground. The microphone is a little instrument invented of late years which is capable of enormously magnifying the very slightest sounds, such as our ears will not detect. ”

“ To get music by radio, a microphone converts sound into electrical modulation, which, carried by radio to distant places, is then changed back into sound and we hear the music.
To get pictures by radio, a sensitive cell converts light into electrical current, and at radio distances changes these currents back into light values, and one may see the distant scene; for light is the thing of which pictures are made, as music is made of sound. ”

“ Again it was proved that the diaphragm or tympanum to receive the impression of the sound and convey it to the carbon button, on which Edison had laid considerable stress, was non-essential; for the microphone, pure and simple, was operated by the direct impact of the sonorous waves, and required no tympanum. Moreover, the microphone, as its name implies, could magnify a feeble sound, and render audible the vibrations which would otherwise escape the ear. The discovery of these remarkable and subtle properties of a delicate contact had indeed confronted Edison ”

“ An audio signal, from the microphone in the helmets or lightweight headsets, is amplified by two microphone amplifiers and then applied to the MODE switch. With the MODE switch in the HF position, the output of the microphone amplifiers is applied to the hf transmitter. When the MODE switch is in the INT position, the output of the microphone is applied to the four headset amplifiers, via the two INT volume controls. With the MODE switch in the HF position, the output of the microphone amplifiers is applied to the uhf transmitter. ”

“ A microphone is an instrument for making extremely small sounds plainly audible. If a current is passed through a box containing loose bits of broken carbon, it meets with great resistance, but if the bits of carbon are compressed their conducting power is considerably increased. Even such slight differences in pressure as are produced by vibrating the box will affect the amount of current passing through the carbon. If this current is led by wires to an ordinary telephone receiver the arrangement becomes a simple form of microphone. ”

“ The Blake transmitter, the Ader, and many others by which music and speech are now conveyed so many miles, are all varieties of the carbon microphone. In some churches, microphone transmitters are now applied to the pulpit, so that the sermon can be transmitted by telephone to invalid members who cannot leave home. At the Electrical Exhibitions of Paris, Vienna, and the Crystal Palace, the music of an entire opera was transmitted from the stage by wire to other buildings where great numbers of persons sat and listened to it. ”

“ The microphone re-transmits it as before, the telephone utters it, and so the process of repetition goes on ad infinitum.
Since the microphone can, as it were, magnify small sounds, and in this respect has some resemblance to the microscope, which magnifies minute objects, it might be thought that it would prove useful for deaf persons. But though the microphone enables a person with good ears to hear mechanical vibrations which otherwise would be inaudible, the sounds that are heard are not in themselves very loud, and hence a dull aural nerve might fail to appreciate them. ”

“ The three nails I have spoken of will not only do all, and that far better than Edison's carbon telephone in telephony, but has the power of taking up sounds inaudible to human ears, and rendering them audible, in fact a true microphone; besides it has the merit of demonstrating the molecular action which is constantly occurring in all matter under the influence of sonorous vibrations. ”

“ During recording sessions at many places, the singers could not be motivated to sing without the installation of a sound system. They have become so accustomed to microphones that the pitch and volume at which they sing has considerably reduced. They feel uncomfortable singing without the microphones. Impractically, they especially like to listen to themselves during the performance by tilting one of the loudspeakers towards themselves. With the use of microphones and amplifiers, the singers do not have to exert themselves. The empathy between the singer and the instrumental players is lost. ”

“ These emanations, as modulated, are projected through space to the receiving sets. There, by a reverse process, they so actuate the receiving mechanisms as to produce a new set of sound waves, of frequencies identical with those produced at the microphone. ”

“ It seems, then, that some scientific men agree that variation of pressure is required to produce action in a microphone, and some of them admit that a microphone with loose contacts will transmit articulate speech, while others deny it, and some admit that a jolting or shaking motion of the parts of the microphone does not interfere with articulate speech, while others say such motion would break the circuit, and cannot be relied on. ”

“ Communicating with every suite of rooms we have the vocaphone. I find it very convenient to have these microphones, as I suppose you would call them, catching your words without talking into them directly as you have to do in the telephone and then at the other end emitting the words without the use of an earpiece, from the box itself, as if from a megaphone horn. Miss Haversham, this is Dr. Klemm. There is a Dr. Kennedy here visiting another patient, a specialist from New York. ”