three. Insert the hearing instrument to the customer's ear while Keeping the probe tube so that its position inside the ear canal just isn't disturbed. Ensure the hearing support is turned off. Subtract the REUR within the REAR across frequencies or subtract the REUG from your REAG across frequencies https://youtu.be/6Cstbsv3DOA?si=UQNio5eGw8lcZCnX