Yes, it is possible for an object to expand or contract without producing any sound or gravitational waves. Sound is a mechanical wave that requires a medium, such as air or water, to propagate. If the object is in a vacuum or an environment where sound cannot travel, there would be no sound produced during its expansion or contraction.
Similarly, gravitational waves are ripples in the fabric of spacetime caused by accelerating massive objects. However, the expansion or contraction of an object alone does not necessarily involve the acceleration of its mass. If the object is not undergoing significant acceleration or movement, it would not generate gravitational waves.
Therefore, if an object undergoes expansion or contraction without generating sound or accelerating its mass, it would not produce any sound or gravitational waves.