An in-well type acoustic telemetry system includes an elongate tubular housing, an elongate transmitter in the tubular housing, and a receiver in the tubular housing. The transmitter is adapted to generate an output acoustic signal by linearly fluctuating along a transmitter axis in response to an electrical signal. The receiver is adapted to generate a second electrical signal by linearly fluctuating along a receiver axis that is parallel to or coincides with the transmitter axis.