SqueezaPulse is a technique for embedding interactivity into fabricated objects using soft, passive, low-cost bellow-like structures. When a soft cavity is squeezed, air pulses travel along a flexible pipe and into a uniquely designed corrugated tube that shapes the airflow into predictable sound signatures. A microphone captures and identifies these air pulses enabling interactivity. The design of 3D-printed corrugated tubes, as well as an informal examination of the effect of different 3D-printed corrugations on air signatures and our resulting SqueezaPulse implementation, are informed by the underlying acoustic theory. To demonstrate and evaluate the potential of SqueezaPulse, we present four prototype applications and a small, lab-based user study (N=9). Our evaluations show that our approach is accurate across users and robust to external noise.