sentences:  Bradbury published his extensive tests to determine this effect in a paper in the Journal of the Audio Engineering Society (JAES) in 1976  and his results agreed that heavily damped lines could reduce the velocity of sound by as much as 50%, although 35% is typical in medium damped lines.Bradbury’s tests were carried out using fibrous materials, typically longhaired wool and glass fibre.These kinds of materials, however, produce highly variable effects that are not consistently repeatable for production purposes.