What happened to my sister-in-law?

Stella suddenly wakes up. When she opened her eyes, she saw a white ceiling. She could only smell the pungent smell of disinfectant when she breathed. “Stella, you are awake.” Seeing Stella open her eyes, Emily immediately put down the thing in her hands and waved her hand in front of Stella. Stella seemed to not react and kept her eyes open. “Stella?” When Tristan, who had just gone out to fetch the water, saw that Stella had woken up, he immediately put the kettle on the table and walked up to Stella. Stella watched as Emily and Tristan close and opened their mouths, but there is no sound. Stella wanted to ask where Adrian was. But she suddenly found that she was not able to make any sound. Emily and Tristan looked at each other as if they had found something. Looking at Stella’s expression, Emily could only turn her head and tried her best to hold back the tears in her eyes. Emily turned around and helped Stella sit up. Stella gradually realized that she couldn’t hear what they were