A reliable, high data rate, downhole acoustic telemetry system is disclosed. In one embodiment, the acoustic telemetry system includes a tubing string with an acoustic transmitter and an acoustic receiver mounted on it. The acoustic transmitter transmits telemetry information by modulating an acoustic carrier frequency that propagates along the walls of the tubing string. The transmitter is preferably mounted at a selected position relative to the end of the tubing string. The selected position is preferably less than &lgr;/4 from the end or approximately n&lgr;/2 from the end, where &lgr; is the wavelength of the carrier frequency in the tubing string, and n is a positive integer. In a more preferred embodiment, n may be the lesser of 4 times the number of cycles in the modulating toneburst and 40. The receiver is preferably mounted at approximately (2n−1)&lgr;/4 relative to the end of the tubing string, where n is a positive integer. Such positioning prevents reflections of the acoustic signal from significantly degrading the received signal. The acoustic signaling advantageously employs pulse shaping to further improve system performance. To enhance data transmission rates, the acoustic receiver advantageously includes an equalizer that compensates for signal dispersion and intersymbol interference while simultaneously minimizing other forms of signal corruption such as additive noise and channel nonlinearities. The equalizer is preferably an adaptive, nonlinear equalizer that may also be fractionally spaced. Such equalizers eliminate any requirements for spacing intervals which allow signal reflections to die out. The resulting system is capable of higher data rates. When error correction codes are employed, no reliability losses are incurred.