Abstract
This study was designed to develop “ducting” techniques for pneumatic noise control and to determine their feasibilities under field conditions. Pneumatic noise was generated under laboratory conditions and characterized by one-third octave-band measurements. Then two forms of ducting were evaluated for their effectiveness in noise control. Static pressures were measured pre- and post-control to evaluate induced back pressure. Variations of the ducting techniques then were applied to several machines under actual work conditions. Analyses of the laboratory measurements indicated a substantial decrease in sound pressure level between pre-control and post-control noise measurements. A slight increase in static pressure also was indicated. Analyses of pre-control and post-control noise measurements during field validation trials showed typical decreases of 10 to 29 dB(A). Therefore, it was demonstrated that ducting effectively reduced pneumatic noise in the work environment and can be utilized as an alternative to mufflers.