KINEMATIC SOUND SCREEN DEVELOPMENT

THE NOISE BARRIER WHICH INCORPORATES THE PRINCIPLE OF THE KINETOSCOPE IS COMPOSED OF SIMPLE TRIANGULAR SHAPED SOLID COLUMNS SEPARATED BY 0.125 - 0.25 COLUMNS. THIS FEATURE HAS A DEGRADING EFFECT ON THE SOUND ATTENUATION CAPABILITIES OF AN OTHERWISE CONVENTIONAL NOISE BARRIER. THE COLUMNS CONSTRUCTED TO ACT AS SIDE-BRANCH RESONATORS WILL HAVE A SEE-THROUGH CAPABILITY AND ACT AS AN EFFECTIVE SOUND BARRIER FOR LOW FREQUENCY NOISE. THE ANGLE BETWEEN THE FACES OF THE ADJACENT COLUMNS WOULD ACT AS AN ACOUSTIC HORN. THE "HORN-EFFECT" WILL DIRECT INCIDENT SOUND ENERGY INTO THE CAVITY OPENINGS, THUS INCREASING THE EFFICIENCY OF THE RESONATING CHAMBER. THE HELMHOLTZ RESONATOR IS DESCRIBED IN DETAIL AND THE PHENOMENON OF RESONANCE IS EXPLAINED. THIS NOISE BARRIER INCORPORATES THE FEATURE OF RELIEVING PASSENGERS IN MOVING VEHICLES OF A WALLED-IN EFFECT AND UTILIZES THE FUNCTION OF HELMHOLTZ RESONATORS TO ABSORB SOUND ENERGY OF LOW FREQUENCY. TEST PANELS OF THE SOUND SCREEN WERE INVESTIGATED IN AN ANECHOIC CHAMBER AND THE PHYSICAL CHARACTERISTICS OBSERVED ARE TABULATED. AT A SOUND FREQUENCY OF 500 HZ, THE PROTOTYPE TEST PANELS GAVE AN ATTUATION VALUE OF 17 TO 20 DBA. A 350 FT. SEGMENT OF 12 FOOT HIGH ALUMINUM SOUND SCREEN WAS USED IN A FIELD EVALUATION. THE MODEL WHICH WAS BUILT FROM 3 FOOT BY- 4 FOOT MODULAR PANELS STACKED FOUR TIERS HIGH ON A CONCRETE PAD AT THE CONSTRUCTION SITE. BOTH LABORATORY AND FIELD TESTS INDICATE THAT THIS DESIGN CAN PROVIDE EFFECTIVE REDUCTION OF LOW FREQUENCY TRAFFIC NOISE AND RELIEVE THE DMOTORIST OF A WALLED IN FEELING. ESTIMATED COSTS PER LINEAL FOOT ARE PRESENTED. IT IS HOPED THAT FUTURE MODIFICATIONS OF THIS BASIC DESIGN WILL EFFECTIVELY ATTENUATE TIRE-ROADWAY NOISE. THE OBSERVATION IS MADE THAT, THEORETICALLY, RESONATING CAVITIES MAY BE DESIGNED FOR ANY ONE OF THE BROAD RANGE OF WAVE LENGTHS ENCOUNTERED IN HIGHWAY NOISE.

• Authors:
  • Morris, G R
  • Hauskins, J
  • Mancini, F P
• Publication Date: 1972-12

Media Info

• Features: Figures; Photos; Tables;
• Pagination: 19 Pd
• Serial:
  • Am Assoc State Highway Officials Proc

Subject/Index Terms

• TRT Terms: Aluminum; Barriers (Roads); Field tests; Kinetics; Laboratory tests; Noise; Noise control; Resonance; Sound absorption
• Uncontrolled Terms: Attenuation; Barriers
• Old TRIS Terms: Resonators
• Subject Areas: Environment; Highways; Safety and Human Factors;

Filing Info

• Accession Number: 00224237
• Record Type: Publication
• Files: TRIS
• Created Date: Oct 24 1973 12:00AM