What are sound waves used for in beauty therapy?

Sound waves are utilized in beauty therapy primarily through ultrasound applications. Ultrasound technology employs high-frequency sound waves that can penetrate the skin to promote various therapeutic and aesthetic benefits. This can include enhancing blood circulation, promoting collagen production, and facilitating the absorption of skincare products by creating micro-vibrations in the skin layers.

In the context of beauty therapy, ultrasound treatments are often employed for skin rejuvenation, body contouring, and cellulite reduction. The waves generate a mechanical effect that can help to stimulate and tighten the skin, making them effective tools in non-invasive cosmetic procedures.

The other options don't accurately represent the applications of sound waves in beauty therapy. Changing skin color is not achieved through sound waves, and light emission is unrelated to sound technology. Chemical reactions typically involve different processes that do not utilize ultrasound. Thus, ultrasound applications stand out as the valid and effective use of sound waves in the beauty industry.