Sound great without it. They are advertised as cotton. My feet and legs normally are sore after playing tennis, but I am amazed after wearing these Adidas shoes the padding must have absorbed the running around I did, and my legs and feet feel great, no soreness! They deliver what they promise. I thought it was my phone, but when I tried another headset, it worked. Now the cover on the other hand. Están increíbles a mi hija le gustaron mucho y la calidad es muy buena, seguro primero ya no le quedan que antes de acabarselas Well, after 3 days of occasional use, these things are so big that they don’t touch the sides, top, or back of my feet. Its almost 500 pages, but it felt like 200. Been 2 months with daily usage around 2-3 hours.