Automatic call tone adjusting telephone set

  • Inventors: TANAKA MASASHI
  • Assignees: Nec Corp
  • Publication Date: May 28, 1988
  • Publication Number: JP-S63124659-A


PURPOSE: To always a call tone with proper sound volume by radiating the call tone whose sound volume is adjusted automatically according to the level of noise around a telephone set. CONSTITUTION: A noise detection means 12 is provided with a noise detection circuit 6 and a microphone 7 and the noise around the telephone set is collected by the microphone 7. An exciting section 8 controls the generating level of a call tone by a control signal obtained for a predetermined time (e.g., 1sec) just before the call signal is inputted and the call tone is radiated. Thus, when the noise around the telephone set is large, the call tone is large and when the noise around the telephone set is small, the call tone gets small and the call tone suitable for listening is obtained. COPYRIGHT: (C)1988,JPO&Japio




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