Four sibs with progressive, bilateral conductive hearing loss are presented. Symmetrical hearing loss averaging 30-60 dB (0.125-8 kHz) became apparent between 8 and 24 years of age. Tympanotomy showed a fixed stapes either through ossified stapedius tendon or through ossified stapedius tendon or through a bony bridge from the stapes to the pyramidal eminence in all patients. After surgical removal of the bony tendon hearing was normal. Both parents, four other sibs, and all grandparents had normal hearing. This family and a further published case suggest a possibly recessive inheritance of this form of conductive hearing loss.