Logarithm of tympanic membrane velocity normalized to background sound pressure measured from the external auditory canal plotted against the frequency of sound stimulus. Results are averaged over four bones per experimental group. Tympanic membrane locations were: A. Posterior superior quadrant, B. Anterior superior quadrant, C. Lateral process of malleus, D. Umbo, E. Posterior inferior quadrant, F. Anterior inferior quadrant. Legend: For each tracing, the thin lines represent frequencies at which the SNR (signal to noise ratio) did not meet our criteria (see text). Thick lines represent frequencies at which the SNR met our criteria.