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. Author manuscript; available in PMC: 2012 May 9.
Published in final edited form as: Cell Rep. 2012 Apr 19;1(4):374–384. doi: 10.1016/j.celrep.2012.02.013

Figure 6. Measurement of distortion-product propagation along Reissner’s membrane.

Figure 6

We show exemplary results from one of three successful in vivo measurements from the chinchilla. (A) The frequency spectrum during stimulation at the primary frequencies f1 = 1.3 kHz and f2 = 1.6 kHz shows the lower-sideband cubic distortion product 2f1 − f2 = 1 kHz. The upper-sideband cubic distortion is weak and comparable to the noise floor. (B) The distortion product disappears after the animal has been sacrificed. (C) Scanning along Reissner’s membrane at the distortion-product frequency 2f1 − f2 reveals a progressive decrease of the signal’s phase, an indication of a traveling wave moving from base to apex. (D) Stimulation at f1 = 2.5 kHz and f2 = 3 kHz evokes the lower-sideband cubic distortion product 2f1 − f2 = 2 kHz. (E) The distortion product vanishes in a dead animal. (F) The phase decline again implies that the distortion product 2f1 − f2 propagates as a forward traveling wave on Reissner’s membrane.