Patent ID: 6234021
Filing Date: 2001-05-22
Classification: G01H,G01N,G01V,G10K

Abstract:
A device for detecting an emission source of an ultrasonic signal against a background of noise, and for producing an audio signal based upon the ultrasonic signal, where the detecting of the emission source is based at least in part on audibility of the audio signal, and where the ultrasonic signal is a dynamic pressure or vibration signal and has one or more frequency components, the device comprising:an ultrasonic sensor for sensing the ultrasonic signal during a predetermined sampling period and producing a sensor signal corresponding to the ultrasonic signal;amplitude characteristic determination means for determining an amplitude characteristic corresponding to the amplitude of the ultrasonic signal during the predetermined sampling period, and for generating an amplitude indication based on the amplitude characteristic;a signal-conditioning system for receiving the sensor signal and for generating the audio signal based on the sensor signal, the signal-conditioning system including at least one amplifier having adjustable gain for causing the audio signal to have an increased amplitude relative to the sensor signal, said amplifier being capable of producing a predetermined maximum voltage; andautomatic gain adjustment means for receiving the amplitude indication and adjusting the gain of the at least one amplifier based at least in part on the amplitude indication and on a predetermined percentage of the maximum voltage of said at least one amplifier to avoid clipping transient signals having increased voltage amplitude relative to said amplitude indication to thereby enhance the audibility of the audio signal.