Apparatus and method for reducing pressure pulsations within drilling mud being pumped downhole by a plurality of pumps to thereby improve quality of mud-pulse telemetry. The apparatus may include a position sensor disposed in association with each pump and operable to generate a position signal indicative of operational timing of a corresponding one of the pumps, a surface telemetry device fluidly connected with the drilling mud and operable to output a telemetry quality signal indicative of the quality of mud-pulse telemetry, and a controller communicatively connected with the pumps, the position sensors, and the surface telemetry device. The controller may be operable to receive the position signal and the telemetry quality signal, and cause the pumps to change relative operational timing of the pumps based on the position signal and the telemetry quality signal to improve the quality of mud-pulse telemetry.