This is a preliminary report of some experiments undertaken to find a method for detecting threatened or potential ankylosis of the stapes before there is any loss of hearing as shown by the usual functional tests. The approach was by way of sounds louder than those of minimum audibility. The idea is to diagnose clinical otosclerosis (or other dyscrasia of the bone about the windows of the labyrinth) so early that experimental observations and preventive treatment may be instituted at a time when they will be of most service. There is no evidence that anything can be done to reverse the otosclerotic process, but it does stop at various stages of development, and early detection would open up possibilities for treatment now unavailable. The background for my experiments was laid on the following observations and hypothesis.
Throughout the ages acuity of hearing has been measured at mini