vibration according to the present invention the generation of this high frequency noise is substantially reduced by the provision of a sleeve 94 which is constructed from a metal that is dissimilar with respect to the metal of the pulley 56 specifically where the body 96 of the pulley is of steel alloy the sleeve 94 should be aluminum which is press fitted about the circumference of the body 96 as a result of the increase in the diameter of the pulley 56 by the provision of the sleeve 94 the pulley 56 will rotate at a lower rotational velocity when in use thus further contributing to a reduction in noise level from this source as illustrated in fig6 it has been discovered that another noise source that can be relatively easily suppressed is found in the balancing holes 98 which are formed in the underside of the tape pulleys 36 according to the present invention the high frequency noise which is emitted when the pulleys 36 are rotated at high speeds can be entirely eliminated by simply cementing or otherwise securely adhering a thin plastic disc or annulus 100 so as to completely cover the balancing holes 98 for each of the tape pulleys thus with this relatively inexpensive modification a source of high frequency noise is eliminated in the lessona 553 machine as well as a number of other false twist texturing machines the gear housing 12 see fig8 has a number of openings which according to the present invention are closed by damped sheet metal panels 102 panels 102 may have their inside surfaces lined with polyurethane foam or other sound absorbing material clearly the panels may be of any desired shape to fit the openings found on a specific housing also sound absorption.