A helmet has shock absorbing devices mounted to the sides thereof and extending to a pair of shoulder pads. More particularly, the present invention relates to polymersomes, viscosifying agents that comprise polymersomes, and associated methods of use. By using this technique with the IS-641 speech coder, it has been found that the present invention improves frame erasure concealment device and method improve the speech quality under various channel conditions, compared with a conventional extrapolation-based concealment algorithm.