Abstract: A device for monitoring the heartbeat of an individual at a pulse point. Fundamentally, the invention comprises two piezoelectric sensors arranged in close parallel relationship with each other and differentially connected to an amplifier circuit. One of the sensors lies over the pulse point of the individual while the other lies therebeside. A rate detector receives the amplified outputs of the sensors and determines the pulse rate from the heart. If this rate exceeds a predetermined level, a signal is passed to enable an oscillator of audible frequency; the output of the oscillator being connected to any earphone speaker to produce a warning sound.