Abstract
Carefully validated longrange sound propagation
measurements with extensive meteorological
instrumentation were continued for 612 days without
interruption, around the clock, resulting in a database
with millions of files, terabytes of sound and
environmental data, and hundreds of pages of
documentation. More than 100 environmental variables were
analysed by statistical means, and many statistically
highly significant dependencies linked to excess
attenuation were found. At a distance of 3 km from the
source, excess attenuation was spread over a dynamic
range of 80 dB, with differences of 10 dB between
individual quarters of the year; also, negative excess
attenuation at frequencies below 400 Hz existed. The low
frequencies were affected mainly by the stability
characteristics of the atmosphere and the lapse rate.
Humidity; lapse rate; sensible heat flux; and
longitudinal, transverse, and vertical turbulence
intensities explain excess attenuation at higher
frequencies to a statistically highly significant extent.
Through application of a wide range of regression
analyses, a set of criteria for frequencydependent
uncertainty in sound propagation was created. These
criteria were incorporated into a software module, which,
together with a stateoftheart physical sound
propagation calculation module, makes it possible to
perform environmental noise assessments with known
uncertainty. This approach can be applied to the
shortterm measurements too and it was shown that some of
the most complex meteorological variables, among them
atmospheric turbulence, can be taken into account.
Comparison with two standardised noise modelling methods
showed that the statistical model covers well a range of
uncertainty notmatched with the standardisedmethods and
themeasured excess attenuation fit within the limits of
predicted uncertainty.
Original language  English 

Qualification  Doctor Degree 
Awarding Institution 

Supervisors/Advisors 

Award date  3 Jan 2014 
Place of Publication  Espoo 
Publisher  
Print ISBNs  9789513881092 
Electronic ISBNs  9789513881108 
Publication status  Published  2013 
MoE publication type  G4 Doctoral dissertation (monograph) 
Keywords
 acoustic wave propagation
 aeroacoustics
 atmospheric acoustics
 environmental acoustics
 environmental noise
 noise assessments
 uncertainty
 statistical model
Fingerprint Dive into the research topics of 'A measurementbased statistical model to evaluate uncertainty in longrange noise assessments: Dissertation'. Together they form a unique fingerprint.
Cite this
Maijala, P. (2013). A measurementbased statistical model to evaluate uncertainty in longrange noise assessments: Dissertation. VTT Technical Research Centre of Finland. http://www.vtt.fi/inf/pdf/science/2013/S48.pdf