Although it's always impressive to see talented artists pull off high notes live on stage, fans can't help but worry about the strain they're putting their vocal cords through 3-4 times a week. The Brown Eyed Girls have been stunning viewers with their dolphin-like pitch at the end of "Sixth Sense", but that doesn't come without effort. Concerned about their health conditions, Nega Network actually tried to restrict their number of promotion stages to once a week. The girls admitted, "It was hard at first because the song had so many high notes, but it was our first comeback in two years, and we sorely missed the stage.  We asked our company to not cut back on the number of live stages a week." They continued, "Our fans worry a lot over our throat conditions.  We've been receiving a lot of bellflower foods and medicines from our fans, which fortunately helps us a lot on stage." Narsha added, "It sometimes gets really tough, but that's all okay." Source + Photos: OSEN