When the ear looks like a septum after a cold, the patient should be suffering from secretory otitis media. There is a tube between the nasopharynx and the middle ear tympanic chamber called the eustachian tube, which regulates the air pressure in the tympanic chamber and maintains the pressure balance inside and outside the eardrum. When you have a cold, inflammation of the nose and nasopharynx or inflammation of the eustachian tube itself causes the eustachian tube to become blocked, the air inside the tympanic chamber is absorbed, the pressure drops, and the eardrum is sunken, resulting in hearing loss and hearing sounds like a membrane, accompanied by symptoms of tinnitus and ear pain. There is also a case that when you blow your nose hard when you have a cold, the disease-causing microorganisms are squeezed into the middle ear from the nasopharynx through the eustachian tube and acute purulent otitis media occurs, which also results in hearing loss accompanied by ear pain, tinnitus and fever. Therefore, when you have a cold, you should actively treat it, keep the nasal cavity clear, and do not blow your nose hard to avoid causing otitis media.