The Sound Reactive Nightgown uses Flexinol, a shape-memory alloy that returns to its original form when it is stimulated. If you yell or speak loudly in the vicinity of this item of apparel, it starts lifting up the hem.
(Sound Reactive Nightgown video)
Fans of JG Ballard recall the fashions of Vermillion Sands, made from bio-fabrics that react to the emotions and moods and noise-level of those nearby:
The racks of gowns itched and quivered, their colors running into blurred pools. One drawback of bio-fabrics is their extreme sensitivity. Bred originally from the gene stocks of delicate wisterias and mimosas, the woven yard have brought with them something of the vine's remarkable response to atmosphere and touch. The sudden movement of someone nearby, let alone of the wearer, brings an immediate reply from the nerve-like tissues. A dress can change its color and texture in a few seconds, becoming more decollete at the approach of an eager admirer, more formal at a chance meeting with a bank manager.