Accession Number:

ADA191289

Title:

Overground Excess Sound Attenuation (ESA). Volume 1. Experimental Study for Flat Grassy Terrains.

Descriptive Note:

Final rept. Jul 79-Jun 87,

Corporate Author:

HARRY G ARMSTRONG AEROSPACE MEDICAL RESEARCH LAB WRIGHT-PATTERSON AFB OH

Personal Author(s):

• Powell, Robert G.

Report Date:

1987-06-01

Pagination or Media Count:

702.0

Abstract:

This is Volume 1 of a 3 volume series concerning overground excess sound attenuation, ESA, i.e. all attenuation in excess of air absorption and inverse square law effects. All three volumes concern a 15-month study conducted at Wright-Patterson Air Force Base, Ohio, over flat, grassy terrain. Volume 1 describes the study and presents the acoustic and meteorological data base that Volumes 2 and 3 use to formulate ESA functions. The study is described in terms of propagation path,instrumentation, reference noise levels, data acquisition techniques, calibration procedures, the noise source and its location. A large portion of this report is devoted to two appendices. Appendix A contain one-third octave band sound pressure levels, overall and A-weighted levels for 415 events. The noise data come from 10 microphones spaced along a 2400 M propagation path. Appendix B lists one-third octave band, overall and A-weighted ESA values in dB. Also included in this appendix are measures of temperature, relative humidity, wind velocity, wind vector relative to source-receiver position, temperature and wind gradients, and meteorological observations, the data in this volume was used to develop a new USAF ESA model which is presented in Volume 3.

Descriptors:

• *ACOUSTIC ATTENUATION
• ACOUSTIC DATA
• AIR
• CALIBRATION
• DATA ACQUISITION
• DATA BASES
• GRADIENTS
• HUMIDITY
• INVERSION
• LEVEL(QUANTITY)
• METEOROLOGICAL DATA
• METEOROLOGY
• METHODOLOGY
• POSITION(LOCATION)
• RECEIVERS
• WIND
• WIND VELOCITY
• GROUND LEVEL
• ACOUSTIC ABSORPTION
• VEGETATION
• ORIENTATION(DIRECTION)
• NOISE(SOUND)
• TABLES(DATA)

Subject Categories:

• Acoustics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE