A systematic review on active noise control technologies in the window

 One of the ways to increase sound transmission inside buildings are doors and windows. A lot of effort has been made to reduce the noise inside the building. This study examines the methods of active sound control in windows.

Methods and Materials: 

In this systematic review, English articles were searched based on the PRISMA guide between January 2020 and December 2021 and in Google Scholar, PubMed, Scopus and ISI Web of Science databases without time limits for publishing articles. The selection of keywords was done based on the principle of Pico and from the Mesh database. Selected keywords were used individually or in combination to search for articles. The articles that had the word noise control in their title or summary along with any related words such as window, transportation, active noise control, active noise canceling, traffic noise, low frequency control, low frequency sounds were selected. Then the titles, abstracts and keywords of these articles were reviewed and related articles were separated from unrelated articles and duplicate articles were also removed. Further, after applying the entry and exit criteria, the full text of the entry articles was collected and analyzed.

 In the first step of the search, a total of 638 studies were found that were published in the investigated databases during the years 2020-2021. Then, by checking the titles of the articles, 456 duplicate or unrelated articles were removed. According to the entry and exit criteria and evaluations and screenings, 97 articles were retrieved, of which 17 articles were included in the study based on the PRISMA guidelines, of which 16 were original articles and one was a review article. The largest number of articles belonged to the researchers of Singapore followed by the United States of America, who accounted for 8 and 5 input articles, respectively.The findings showed that the main solutions to prevent the transmission of sound inside the building include three categories: passive control, active control, and hybrid sound control. Active sound control methods are performed according to the closed and open status of the window in different ways such as cavity control, speaker installation on the window frame, speaker installation in the wall, short duct control.

 Today, active sound control is considered as a potential solution to control low-frequency sounds and traffic noise. Using the active sound control method for glass windows improves sound transmission loss without increasing the mass of the window. Due to geographical and cultural differences, the application of active sound control systems on windows is done in three main categories, fully closed windows, fully open windows and half-open windows. It is suggested that researchers focus more on absorbent layer technologies, calculation methods and numerical simulations.