Hearing screening system for a subject or a patient, and a method for hearing screening

A hearing screening system for a subject or patient, the system comprising:

• auditory stimulus device configured to apply an auditory stimulus to at least one ear of the subject or patient;
• at least three electrodes for electrically connecting to at least three different positions on a head of the subject or patient for measuring respective potential changes in response to the auditory stimulus;
• a first power supply having first supply terminals for supplying a first supply voltage;
• a second power supply having second supply terminals for supplying a second supply voltage;
• a first differential amplifier being arranged for receiving the first supply voltage, the first differential amplifier having a first pair of inputs coupled to a first pair of electrodes selected from the at least three electrodes, the first differential amplifier being arranged for amplifying a first potential difference between the first pair selected from the electrodes for obtaining a first electroencephalographic (EEG) signal on a first output of the first differential amplifier, and
• a second differential amplifier being arranged for receiving the second supply voltage, the second differential amplifier having a second pair of inputs coupled to a second pair of electrodes that is different than the first pair of electrodes and that is selected from the at least three electrodes, the second differential amplifier being arranged for amplifying a second potential difference between the second pair selected from the electrodes for obtaining a second EEG signal on a second output of the second differential amplifier;
• wherein the first supply voltage and the second supply voltage are galvanically isolated from each other.