it makes the noise in both ears, with the cable unplugged, and using a 'standard' duracell aaa battery (1.5 v). with my head titled to the right, the cracks are most prominent in the left channel, and vice versa. it seems a little more sensitive when tilting to the left than the right, but maybe my head just tends to tilt left more often than not. the cracks are more pronounced when the cable is plugged into my headphone jack w/ nothing playing. the cable isn't plugged into my headphones right now and i can hear the cracking, and it's very undesirable.