Fig. 2.

(Color online) (a) Measured voltages using the PCD and hydrophone as receivers for the pulse-echo technique. (b) Measured voltages using the PCD and hydrophone as receivers for the pitch-catch technique. (c) Frequency-dependent, absolute PCD receive sensitivities $M_{\text{PCD}}(f)$ determined using the pulse-echo and pitch-catch techniques, with error bars representing the uncertainty of the PCDs receive sensitivity.