A biological information monitoring system comprising: an alarm generator which generates an alarm signal indicative of an abnormality of biological information of a patient, or an abnormality of a unit related to monitoring of biological information of a patient, or an abnormality due to an operation of a unit related to monitoring of biological information of a patient; a biological information processor that receives the alarm signal from the alarm generator, converts the alarm signal to an alarm output, outputs the alarm output along a first data path, and outputs one of the alarm output and a notification signal indicating presence of the alarm output along a second data path; a first output generator connected to the biological information processor along the first data path, the first data path beginning at the biological information processor and terminating at the first output generator; a sound driver which receives the alarm output from the biological information processor along the first data path and drives the first output generator to output a first alarm based on the alarm output, the sound driver connected between the biological information processor and the first output generator along the first data path; a detector which detects the alarm output at an input side of the sound driver and an output side of the sound driver along the first data path and outputs an output signal indicating presence of the alarm output detected along the first data path; a second output generator which outputs a second alarm independent from the first alarm; and a warning controller directly connected to the biological information processor along the second data path, the second data path beginning at the biological information processor and terminating at the warning controller which receives (i) a first input of the one of the alarm output and the notification signal indicating presence of the alarm output from the biological information processor along the second data path and (ii) a second input of the output signal from the detector, determines a malfunction condition that exists when (a) the first input is received and the second input is not received or (b) the first input is not received and the second input is received, and controls the second output generator to output the second alarm in response to determining the malfunction condition. an alarm generator which generates an alarm signal indicative of an abnormality of biological information of a patient, or an abnormality of a unit related to monitoring of biological information of a patient, or an abnormality due to an operation of a unit related to monitoring of biological information of a patient; a biological information processor that receives the alarm signal from the alarm generator, converts the alarm signal to an alarm output, outputs the alarm output along a first data path, and outputs one of the alarm output and a notification signal indicating presence of the alarm output along a second data path; a first output generator connected to the biological information processor along the first data path, the first data path beginning at the biological information processor and terminating at the first output generator; a sound driver which receives the alarm output from the biological information processor along the first data path and drives the first output generator to output a first alarm based on the alarm output, the sound driver connected between the biological information processor and the first output generator along the first data path; a detector which detects the alarm output at an input side of the sound driver and an output side of the sound driver along the first data path and outputs an output signal indicating presence of the alarm output detected along the first data path; a second output generator which outputs a second alarm independent from the first alarm; and a warning controller directly connected to the biological information processor along the second data path, the second data path beginning at the biological information processor and terminating at the warning controller which receives (i) a first input of the one of the alarm output and the notification signal indicating presence of the alarm output from the biological information processor along the second data path and (ii) a second input of the output signal from the detector, determines a malfunction condition that exists when (a) the first input is received and the second input is not received or (b) the first input is not received and the second input is received, and controls the second output generator to output the second alarm in response to determining the malfunction condition.