Examples of hearing assistance devices are described. The hearing assistance devices include an enclosing structure configured to house a receiver that generates sound waves into an ear canal of a user when the hearing assistance device is worn, and a tube coupled to the receiver to direct the sound waves into the ear canal of the user. The tube may include magnetized particles that form a magnetic field through the tube. The tube may include a portion of hydrophilic coating and a portion of hydrophobic coating. The hearing assistance device may include a coiled wire configured to carry an alternating current to generate an electro-magnetic field through the tube.