Abstract: A telephone handset acoustic coupling cup adapted for use as part of an acoustic data coupler wherein the cup has a flexible, gripping lip surrounding an opening for receiving a telephone handset transmitter or receiver case. Each of two acoustic coupling cups may additionally be eccentrically rotatably mounted on a case in a manner that their openings may be varied in distance from one another by rotating the cups with respect to the case. The cups may also be flexible in a manner to be bendable with respect to said case, all with the view of providing an acoustic data coupler that can accept a wide variety of different sizes and shapes of telephone handsets.