In fact, not only Old Qian heard it, but He Kao also heard the conversation among the three people. The more he listened, the colder he felt behind his back.
Don't ask how He Kao heard it; it's a peculiar ability that he explored on his own. When he controlled his emotions to empty his mind, he became externally solid yet internally hollow, and various noises from the outside seemed to pour in.
The so-called sound is not necessarily just voice. It includes various chaotic information like sound, light, temperature, touch, etc. Since he couldn't differentiate them, he chose not to, and this was He Kao's recent entry-level cultivation method.
It was easier than imagined. He seemed to quickly reach entry-level, meaning he could achieve a state of "not needing to differentiate," and then suddenly discovered he could "differentiate" again, as long as he focused his attention on a specific object.
