A speech synthesis system is disclosed that utilizes a pitch contour resulting in a more natural-sounding speech. More particularly, the invention provides substituted aryl sulfonamides, compositions comprising these compounds, as well as methods of using these compounds or compositions in the treatment of central or peripheral nervous system disorders, particularly pain and chronic pain by blocking sodium channels associated with the onset or recurrence of the indicated conditions. An engine is also mounted within the shock absorber for converting the translational movement into rotational movement. This achieves dynamic attenuation of the noise in a manner that is particularly simple and low cost, while also being very effective in suppressing discharge noise.