Brianna tells Claire after Geillis goes through the stones that she heard them. Both Claire and Brianna hear the stones. Roger also appears to have heard the stones. This seems to be an indication you have the ability to travel.
Initially, when Claire went through the stones there was a strange buzzing sound.
Since the beginning, all time travelers have heard something similar to bees buzzing and the sound of Chaos and even war when going through the stones.
