Subject <Equals> "Acoustics" <Equals> "true" Subject <Equals> "Akustik" Subject <Equals> "Absorption" Subject <Equals> "Nachhallzeit" Subject <Equals> "Aktive Lärmminderung" Subject <Equals> "Aktive Absorption" Subject <Equals> "Active noise control" Date Issued <Equals> "2012" Subject <Equals> "Reverberation"