章 320: Chapter 320 - No longer safe

Yue met up with his family. Now the wait happens. They had to ring the special bell to warn all the remaining survivors here.

It was a specially made bell that rang at five thousand hertz. After years of testing, Qian was able to assure them that only humans could hear its special frequencies of sound. The zombified human lost that ability to hear this frequency.

With that in mind, an alarm bell was made. In case of zombies infiltrated they could ring and warn only the humans of the danger.

In a second, a loud ringing sound rang out.

Yue felt his headache slightly. He squatted down and cupped Zi Chen's ears. Higher frequencies of sound were very bad for children. As well as for older people….

He glanced back at his father. He frowned slightly.