US1709747A - Electrical apparatus for persons defective in hearing - Google Patents

Electrical apparatus for persons defective in hearing Download PDF

Info

Publication number
US1709747A
US1709747A US130291A US13029126A US1709747A US 1709747 A US1709747 A US 1709747A US 130291 A US130291 A US 130291A US 13029126 A US13029126 A US 13029126A US 1709747 A US1709747 A US 1709747A
Authority
US
United States
Prior art keywords
microphone
hearing
persons
amplifying
receiving
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US130291A
Other languages
English (en)
Inventor
Sell Helmut
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Siemens and Halske AG
Siemens Corp
Original Assignee
Siemens Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Siemens Corp filed Critical Siemens Corp
Application granted granted Critical
Publication of US1709747A publication Critical patent/US1709747A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R23/00—Transducers other than those covered by groups H04R9/00 - H04R21/00
    • H04R23/02—Transducers using more than one principle simultaneously

Definitions

  • the invention relates to electrical apparatus for persons with defective hearing and more particularly to such apparatus in which an amplifying microphone is provided.
  • the present invention has for its object the construction of an appliance for the deaf embodying an amplifier which has the very high est efliciency with respect tosound amplification and quality of transmission and which is nevertheless so small that it can conveniently be concealed inany pocket of the clothing (in the vest pocket, for example).
  • an appliance for the deaf embodying an amplifier which has the very high est efliciency with respect tosound amplification and quality of transmission and which is nevertheless so small that it can conveniently be concealed inany pocket of the clothing (in the vest pocket, for example).
  • the current consun'lptionl of the amplifier be very'small, with a correspondingly low E. M. F. so that the source of current may be kept quite small. In most cases a single element, giving'an E. M. F. of 1.5 volt sul'lices.
  • microphones produclug a particularly high quality ot speech may be used. For the same reason the'employment of several microphones can.
  • Figure 1 illustrates a general View of a constructional form of the invention
  • Figures 2-4 show in section, in front ele vation and in rear elevation, respectively, the amplifier which, is constructed as an amplifyingmicrophone, as will be described more fully hereinafter, and
  • Figure 5 is a wiring diagram of an illusing cords altogether unnecessary, excepting the current lead 4 which connects the amplifying microphoneto a so-called ear-telephone 5 which is inserted into'the'ear, and the type of which is generally known in the art, for instance as represented by my U. S.
  • the amplifier may be mounted on the battery.
  • the amplifier may also be employed as an auxiliary unit, in conjunction with the usual appliances for deaf persons.
  • a large number of combinations of the individual elements of the apparatus may be employed to meet various requirements.
  • the novel amplifier which is fully described in my U. S. Patent No. 1,624,511, comprises a microphone which is 'electro-m'ag- ,netically controlled. Numerous devices of this sort are known, but in practice no such apparatus has given ultimate satisfaction. All amplifiers operating on this principle have been supplanted by the valve amplifier. The reason for this resides firstly in the fact that as a rule the apparatus require very fine adjustment and are exceedingly sensitive to shocks and vibrations. 'Furtherand this is the most important pointthe quality of their speech transmission suflices only for very few cases.
  • the device which forms the subject matter of this invention is free from these deficiencies. This result has been obtained by a particular construction both of the microphone and of the existing system. It is known that an essential cause of distortion in microphones is to be found in the properties of the diaphragm. That is to say, the diaphragms usually employed generally exhibit, within certain. ranges of frequencies, very pro nounced natural oscillations, which accentuate individual frequencies of the transmitted sound. This phenomenon is noticeable to an unpleasant degree in the common application of the microphone in conjunction with telephones. It isincomparably emphasized, however, when such a microphone 1s used as one element of a microphonic amplifier.
  • a further cause of distortion lies in defectivefunctioning of the microphonic contacts. Apart from the distortions broughtabout by the diaphragm, the current fluctuations 'do not completely correspond to the impressed oscillations.
  • the cause of this phenomenon liesin the fact that in microphones, as a rule, a relatively small number of contacts between the carbons come into operation, which are influenced mechanically in an absolutely uncontrollable manner.
  • carbon dias phragn' are employed and constitute one electrode of the microphone, while the other electrode is formed of a block of'ca'rbon provided with pan-shaped-depressions in which are located little, carbon bodies (balls or ranules) which form contacts with the diaphragm, on the one hand, and with the depressions, on the other hand.
  • the microphone comprises a granule chamber 11 closed at one side by a thin stretched metal foil 12 having its surface-covered with a precious metal (for instance by gold plating), while the opposite side is likewise bounded by a plane surface, constituted as an insulating body 16, having a central conducting portion 13 in the same plane.
  • This disc-shaped chamber which has a thickness of a few millimetres, with a diam eter of, say, 25 millimetres, is completely filled with proportionately fine carbon granules, to such a'degree, however, that these granules are only under the pressure due to their own weight.
  • the fine granule filling produces very good average transmission for all loads, since very many'contacts come into operation.
  • the diaphragm used in the microphone, in co-operation with the carbon granules possesses special hysical properties.
  • the diaphragm is ma e of a metal of high elasticity, phosphor bronze, for preference. It has a thickness of about 1/ 100th m. 111.
  • To its center is soldered a disc-shaped armature 14 of about 10 m. m. diameter of a thickness of about 2/10th m. m.
  • the foil is fastened to a carrier ring 15, preferably by soldering and is stretched radially by a suitable annular rid e 17 on the insulating body 16 which forms t e chamber.
  • the diaphragm With an unfilled chamber, the diaphragm, so stretched possesses a pronounced natural frequency but, in contradistinction to other masses present on both sides of the nodal of very smallweight, its natural frequency,
  • the magnet system is provided with-concentric poles,one of which surrounds the other, one being a central rod 18, an annular plate 19 surrounding the same.
  • the rod 18 and plate 19 are, by means of suitable pole pieces 21 and 22 magnetically connected to the poles of a permanent magnet 20,
  • the mass of the armature may be very small.
  • the two-poles are as a rule rather widely separated on account of the winding interposed between them. Consequently the armature in such systems must be larger.
  • Stouter material must also be chosen, because the magnetic path is longer.
  • the magnet properties of the armature are utilized to the fullest advantage.
  • the sound waves which after proper amplification are to be transmitted to the ear of the user by means of the ear telephone 5, first.
  • the receiving microphone 1 which may be of a conventional construction not specifi cally shown'here,.but which should be of such character vthat it reproduces electrically a high quality of speech as aforementioned.
  • the speaking currents-produced in the well known-manner by the resistance variation in the carbon granule filling of the microphone are not, as it was customary heretofore, directly transmitted to the 'ear phone 5, but are conducted into the energizing coil 25 of the microphonic amplifier shown in Figures 2, 3
  • This coil 25' constitutes the electro-magnetic portion of the amplifying microphone.
  • the effect of these currents in the latter microphone is the setting into vibration of the diaphragm 12, so that the latter can transmit its vibrations to the carbon filling 11 of the" amplifier, and
  • Electrical hearing apparatus for persons defective in hearing, comprising in combination a receiving microphone for receiving the sound, an amplifying microphonic de vice electrically connected in cascade to the receiving microphone and being itself substantially insensitive to direct sound striking it from outside, a telephone receiver connected to said amplifying microphone, and a source of current suitably connected to said receiving and said amplifying microphone and to said telephone for energizing said instrumentalities.
  • Electrical hearing apparatus for persons defective in hearing, comprising in com- 'bination a receiving microphone for receiving the sound. an amplifying microphonic device electrically connected in cascade to the receiving microphone, a casing surrounding said amplifying device 'to make it substantially sound proof against direct soundsstriking it from outside, a telephone receiver connected to said amplifying microphone, and a source of current suitably connected to said receiving and amplifying microphones and to said telephone for energizing said instrumentalities.
  • Electrical hearing apparatus for persons defective in hearing, comprising in combination a receiving mlcrophone for receiving the sound, an amplifying microphonic device electrically connected in cascade to said receiving nncrophone and being itself substantially insensitive to direct sound striking it from outside, the speech reproducing qualities of said receiving microphone being higher than those of said ampllfying device while the sound sensitivity of the receiving microphone is lower than that of the amplifying device, a telephone receiver connected to said amplifying microphone, and a source of current suitably connected to said receiving and said amplifying microphone and to said telephone for energizing said instrumentalities.
  • Electrical hearing apparatus for persons defective in hearing, comprising in combination a receiving microphone for receiving the sound.
  • an amplifying microphonic device electrically connected in cascade to the receiving microphone, the speech reproducing qualities of said receiving microphone being higher than those of said am lifying device while the sound sensitivity 0 the receiving microphone is lower than that of the amplifying device, a casing surrounding said amplifying device to make is substantially sound proof against directsounds striking it from the outside,'a telephone receiver connected to said amplifying microphone," nd a source of current suitably connected to aid receiving and said amplifying microphone and to said telephone for energizing said instrumentalities.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Audible-Bandwidth Dynamoelectric Transducers Other Than Pickups (AREA)
  • Diaphragms For Electromechanical Transducers (AREA)
  • Telephone Set Structure (AREA)
US130291A 1925-08-27 1926-08-19 Electrical apparatus for persons defective in hearing Expired - Lifetime US1709747A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DES71274D DE460940C (de) 1925-08-27 1925-08-27 Tragbares Schwerhoerigengeraet mit Verstaerkeranordnung

Publications (1)

Publication Number Publication Date
US1709747A true US1709747A (en) 1929-04-16

Family

ID=5966502

Family Applications (1)

Application Number Title Priority Date Filing Date
US130291A Expired - Lifetime US1709747A (en) 1925-08-27 1926-08-19 Electrical apparatus for persons defective in hearing

Country Status (4)

Country Link
US (1) US1709747A (de)
DE (1) DE460940C (de)
FR (1) FR604032A (de)
GB (1) GB257563A (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2673898A (en) * 1951-06-01 1954-03-30 Sonotone Corp Wearable hearing aid having external microphone with penetrating pin connector structure
DE1114731B (de) * 1957-10-16 1961-10-05 Wasagchemie Ag Einweg-Kolbenschieber fuer Sprengoel-Foerderleitungen

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2673898A (en) * 1951-06-01 1954-03-30 Sonotone Corp Wearable hearing aid having external microphone with penetrating pin connector structure
DE1114731B (de) * 1957-10-16 1961-10-05 Wasagchemie Ag Einweg-Kolbenschieber fuer Sprengoel-Foerderleitungen

Also Published As

Publication number Publication date
FR604032A (fr) 1926-04-28
DE460940C (de) 1928-06-12
GB257563A (en) 1926-12-02

Similar Documents

Publication Publication Date Title
US4151379A (en) Electromagnetic speaker with bucking parallel high and low frequency coils drives sounding board and second diaphragm or external apparatus via magnetic coupling and having adjustable air gap and slot pole piece
JPH0155640B2 (de)
GB594646A (en) Improvements in or relating to directional microphones
US1709747A (en) Electrical apparatus for persons defective in hearing
JPWO2005006809A1 (ja) 圧電型振動発生器及びこれを用いた振動送音器
De Forest The audion-detector and amplifier
US1732393A (en) Electrostatic phonograph pick-up
US3562429A (en) Sound transmitter with feedback and polarization circuitry
US2031789A (en) Acoustic electric energy converter
US1534148A (en) Sound-translating apparatus
US2105296A (en) Hearing aid
US1952577A (en) Mechanical amplifier
US2552800A (en) Magnetic microphone
US1631646A (en) Sound-reproducing apparatus
US2922849A (en) Compound electric speaker
US1375707A (en) Tuning of diaphragms for generating or receiving sound-waves
US1554561A (en) Sound-reproducing mechanism
US2121941A (en) Sound transmitting apparatus
US436513A (en) Telephone
US245105A (en) Telephone
US1878232A (en) Sound reproducing device
US2122191A (en) Sound translation apparatus
US2542017A (en) Combined electromagnetic piezoelectric phonograph translating device
US252641A (en) Compound telephone
CN214205598U (zh) 发声装置和电子设备