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Patent Searching and Data


Title:
LOUDSPEAKING TELEPHONE
Document Type and Number:
Japanese Patent JPS60114056
Kind Code:
A
Abstract:

PURPOSE: To let a user notice a surrounding noise level and enable him to make an appropriate voice level call by providing a level meter indicating peripheral noise levels to a loudspeaking telephone set.

CONSTITUTION: Transmission rectification output of a transmission rectification circuit 11 drives a level meter 15 through a meter driving amplifier circuit 14. In normal condition of distinguishing a periphery noise from sound signals, an easy noise meter can be constituted, which indicates noise levels to be inputted in a microphone 1 on a level meter 15 by giving characteristics analogous to audible sense correction characteristics A of JIS C1502 to frequency characteristics of the circuit 11 because accoustic energy of the periphery noise is in most part contained in a low frequency area. Therefore, in case of a user not uttering any sound, the user can know proper sound level because the meter 15 displays the periphery noise level collected.


Inventors:
OOTA SEIZOU
Application Number:
JP22286283A
Publication Date:
June 20, 1985
Filing Date:
November 26, 1983
Export Citation:
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Assignee:
NIPPON ELECTRIC CO
International Classes:
H04M1/60; H04M9/08; (IPC1-7): H04M1/60
Attorney, Agent or Firm:
Kurita Haruo