FR639320A - Improvements to hearing devices - Google Patents

Improvements to hearing devices

Info

Publication number
FR639320A
FR639320A FR639320DA FR639320A FR 639320 A FR639320 A FR 639320A FR 639320D A FR639320D A FR 639320DA FR 639320 A FR639320 A FR 639320A
Authority
FR
France
Prior art keywords
hearing devices
hearing
devices
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
Application number
Other languages
French (fr)
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.)
Electrical Research Products Inc
Original Assignee
Electrical Research Products Inc
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 Electrical Research Products Inc filed Critical Electrical Research Products Inc
Application granted granted Critical
Publication of FR639320A publication Critical patent/FR639320A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R19/00—Electrostatic transducers

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Audible-Bandwidth Dynamoelectric Transducers Other Than Pickups (AREA)
  • Soundproofing, Sound Blocking, And Sound Damping (AREA)
  • Electrostatic, Electromagnetic, Magneto- Strictive, And Variable-Resistance Transducers (AREA)
FR639320D 1926-10-20 1927-08-11 Improvements to hearing devices Expired FR639320A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US142790A US1722347A (en) 1926-10-20 1926-10-20 Acoustic apparatus

Publications (1)

Publication Number Publication Date
FR639320A true FR639320A (en) 1928-06-19

Family

ID=22501288

Family Applications (1)

Application Number Title Priority Date Filing Date
FR639320D Expired FR639320A (en) 1926-10-20 1927-08-11 Improvements to hearing devices

Country Status (6)

Country Link
US (1) US1722347A (en)
BE (1) BE345155A (en)
DE (1) DE519901C (en)
FR (1) FR639320A (en)
GB (1) GB279390A (en)
NL (1) NL22541C (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2500643A (en) * 1946-12-07 1950-03-14 Bell Telephone Labor Inc Condenser transducer independent of ambient atmospheric conditions
JPS5121791B2 (en) * 1972-08-04 1976-07-05

Also Published As

Publication number Publication date
DE519901C (en) 1931-03-06
NL22541C (en)
BE345155A (en)
GB279390A (en) 1928-10-22
US1722347A (en) 1929-07-30

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