This report describes manometric apparatus developed for registering the involuntary displacements of the human tympanic membrane during the reflex contraction of the middle‐ear muscles. Recent tests with the new method have been uniformly successful in 14 inexperienced subjects, as contrasted with only 20 out of 57 previously. The reflex reactions have also been recorded from subjects who had been judged nonreactors in previous tests. Extensive repetitions of tests on one subject have yielded a close quantitative relation between stimulus and response‐index magnitudes. In this set of experiments the stimulus was a click‐free tone of 500 cps, graded in steps of 1 db. The threshold sound pressure level was about 111 db, and response magnitude rose in sigmoid fashion with progressively stronger stimuli.