The laboratory facilities and apparatus described in an earlier paper were used to study the normal intensity and frequency limits of audition for bone conduction. The condition of the observer's head to give greatest acuity for pure tones, and the optimal total force of application and area of the vibrator button were found to be essentially the same as for speech sounds. Acuity was found to vary with the position of application of the vibrator; for example, the maximum variation with position of the 1000‐cycle threshold was 18 db. A threshold for open canals was determined for the frequency range 80–2000 cycles, without interference from stray air radiation (18 normal observers). Above 2000 cycles air radiation interfered with open canal tests to such an extent that a special technique was devised to obviate its effects. The occluded threshold curve, for a single normal individual, lay below his open canal curve over the range 80–2000 cycles, and also at 10,000 cycles. The usable intensity range for open canals was tentatively determined; it is a maximum of 80–90 db at 1000–2000 cycles. The total audible frequency range for open canals was found to be at least 25–17,000 cycles.