Clean any debris found on the microphone by using a dry cloth or brush.
Clean the tip of the hearing aid that goes inside your ear with a dry cloth.
Remove the dome from your hearing aid to see if there is any wax plugging the wax guard. However, if you’re not hearing any sound, there may be some hidden wax behind the wax guard.
Change the wax guard if needed.
Check the receiver wire to see if it has any kinks or twists, as this may lead to malfunction.