Conductive hearing loss

A 42-year-old man goes to his primary care physician for evaluation of hearing loss. The patient has had worsening hearing loss out of the right ear for the past six to nine months. He has also been experiencing intermittent ringing in the affected ear. Family history is notable for similar symptoms in his father, who developed progressive hearing loss starting at the age of 35. On physical exam, temperature is 37.5°C (99.5°F), blood pressure is 147/88 mmHg, and pulse is 73/min. Otoscopy of the patient's right tympanic membrane demonstrates the finding below. Audiometric testing demonstrates low-frequency hearing loss in the right ear.



  Image reproduced from Wikimedia Commons 

Which of the following best describes the pathophysiology of this patient's condition?