Abstract: An accident sound detector counts the number of records of detected accident sounds in a predetermined period of time. The accident sound detector varies the amplification of input sound signals according to the number of records or their variation to limit the number of records, thereby making it possible to increase the recording time of a recording medium without overwriting the records. The detector includes an amplifier for amplifying a sound signal from an ambient sound detector. An accident sound detector circuit and a record controller detect and record an accident sound by comparing an output value from the amplifier to a threshold. A counter circuit counts the number of detected signals of the accident sound detector circuit. A comparator compares the count value of the counter circuit with a reference count value. An amplification controller circuit controls the amplification of the amplifier based on output of the comparator.
Type:
Grant
Filed:
March 24, 1998
Date of Patent:
August 24, 1999
Assignee:
Mitsubishi Electric Engineering Company, Ltd.