JPS57186900A - Acoustic device - Google Patents

Acoustic device

Info

Publication number
JPS57186900A
JPS57186900A JP7255781A JP7255781A JPS57186900A JP S57186900 A JPS57186900 A JP S57186900A JP 7255781 A JP7255781 A JP 7255781A JP 7255781 A JP7255781 A JP 7255781A JP S57186900 A JPS57186900 A JP S57186900A
Authority
JP
Japan
Prior art keywords
signal
circuit
loudspeaker
switching
sound
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.)
Pending
Application number
JP7255781A
Other languages
Japanese (ja)
Inventor
Isamu Yokoyama
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.)
Mitsubishi Electric Corp
Original Assignee
Mitsubishi Electric 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 Mitsubishi Electric Corp filed Critical Mitsubishi Electric Corp
Priority to JP7255781A priority Critical patent/JPS57186900A/en
Publication of JPS57186900A publication Critical patent/JPS57186900A/en
Pending 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
    • H04R27/00—Public address systems

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Circuit For Audible Band Transducer (AREA)

Abstract

PURPOSE:To adjust sound volume suitably in accordance with an ambient noise, by switching a sound signal output by a detecting circuit, and using a loudspeaker as a noise detector, in case when a sound signal from a voice generating source has become a prescribed level or below. CONSTITUTION:When a sound signal (a) from a sound signal generating source 1 such as a radio broadcast, a cassette, etc. is outputted and its signal level has become a prescribed value or below, for instance, zero, a detecting circuit 6 generates a switching signal (b) consisting of a pulse. In accordance with this switching signal (b), an amplifying circuit 3 is separated from a loudspeaker 5 by a switching circuit 4, and the loudspeaker is connected to a controlling means 10. As a result, the loudspeaker 5 detects an ambient noise and obtains a noise signal (d). This signal is amplified and detected by an amplifying circuit 7 and a detecting circuit 8, respectively, and a control signal (e) is outputted by an integration circuit 9. A voltage control gain adjusting circuit 2 amplifies the sound signal (a) by an amplification factor corresponding to a level of the control signal (e), by which sound volume is controlled.
JP7255781A 1981-05-12 1981-05-12 Acoustic device Pending JPS57186900A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP7255781A JPS57186900A (en) 1981-05-12 1981-05-12 Acoustic device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP7255781A JPS57186900A (en) 1981-05-12 1981-05-12 Acoustic device

Publications (1)

Publication Number Publication Date
JPS57186900A true JPS57186900A (en) 1982-11-17

Family

ID=13492768

Family Applications (1)

Application Number Title Priority Date Filing Date
JP7255781A Pending JPS57186900A (en) 1981-05-12 1981-05-12 Acoustic device

Country Status (1)

Country Link
JP (1) JPS57186900A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63293599A (en) * 1987-05-26 1988-11-30 クラリオン株式会社 Electronic siren

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63293599A (en) * 1987-05-26 1988-11-30 クラリオン株式会社 Electronic siren

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