I bought two of these, one for me, one for my wife. In a random fashion, either the left ear or the right ear will "go deaf". Occasionally both ears will "go deaf". My wife's jack is so loose that it simply separates from the nano with the slightest movement! I get the same problems when I use my Bose earphones. The reason seems to be that the audio jack ports on this product have been manufactured without adequate attention to quality control. Short of returning the nanos, can you think of a solution?