M. S. Longuet-Higgins has predicted [J. Fluid Mech. 201, 525–541 (1989)] that the distortion modes of a bubble can produce, through nonlinear coupling, a monopole radiation of sound. Here, some preliminary results are presented of an experiment designed to investigate this phenomenon. A hydrophone and needle are submerged in water in a small (6.5×6.5×7.0 cm3) sealed cell that is connected to a regulated evacuation system for pressure control. The sound radiation produced by releasing a bubble from the needle is monitored by a hydrophone and displayed on a digital oscilloscope. Two high-speed video cameras simultaneously record the motion of the bubble and the sound radiation trace as displayed on an analog oscilloscope. At low pressures (i.e., a few cm Hg), it is seen that after the pinch-off sound dies out, there follows a sound of the same frequency but with a lower and relatively constant magnitude, which we believe is evidence of the coupling between surface and volume modes. Observation of the phase between the surface oscillation and the radiated sound indicates a causal relationship. [Work supported by ONR.]