Synopsis from Goodreads

SOUND is the stand-alone companion to Alexandra Duncan’s acclaimed novel Salvage, a debut that internationally bestselling author Stephanie Perkins called “kick-ass, brilliant, feminist science fiction.” For fans of Beth Revis, Firefly, and Battlestar Galactica. As a child, Ava’s adopted sister Miyole watched her mother take to the stars, piloting her own ship from Earth to space making deliveries. Now a teen herself, Miyole is finally living her dream as a research assistant on her very first space voyage. If she plays her cards right, she could even be given permission to conduct her own research and experiments in her own habitat lab on the flight home. But when her ship saves a rover that has been viciously attacked by looters and kidnappers, Miyole—along with a rescued rover girl named Cassia—embarks on a mission to rescue Cassia’s abducted brother, and that changes the course of Miyole’s life forever.