Road traffic and aircraft noise are among the most widespread environmental noise problems globally and closely linked to negative health effects.As a result, they are subject to stringent national and international regulations.Aircraft certified for airworthiness must also comply with increasingly high noise standard requirements to receive a noise certification.And for each category of ground vehicles, government agencies set pass-by noise emission limits–critical regulations that must be respected and are a requirement for all automotive OEMs as part of product certification。