Journal of Building Engineering 41 (2021) 102752 Available online 27 May 2021 2352-7102/© 2021 Elsevier Ltd. All rights reserved. Use of date palm waste fbers as sound absorption material Ebrahim Taban a , Somayeh Amininasab b , Parham Soltani c , Umberto Berardi d, * , Debelo Dugasa Abdi e , Seyed Ehsan Samaei f a Department of Occupational Health Engineering, School of Health, Mashhad University of Medical Sciences, Mashhad, Iran b Department of Acoustic, Road, Housing and Urban Development Research Center (BHRC), Tehran, Iran c Department of Textile Engineering, Isfahan University of Technology, Isfahan, 84156-83111, Iran d Department of Architectural Science, Ryerson University, Toronto, ON, M5B 2K3, Canada e Department of Occupational Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran f Department of Occupational Health Engineering, School of Public Health, Mazandaran University of Medical Sciences, Sari, Iran A R T I C L E INFO Keywords: Date palm waste fber Sound absorption Impedance tube Reverberation room Circular economy ABSTRACT An increasing interest in the possibilities of converting agricultural wastes to value-added products has emerged. Annually, 200,000 tons of date palm waste are generated, which are charred or released as agricultural wastes. This work describes the efforts to fabricate low-cost sound-absorbing panels from date palm waste fbers and assess their performance for sound absorbing applications. Samples of different thicknesses (25, 35, 45, and 55 mm) and densities (125 and 175 kg/m3) were produced. The normal-incidence sound absorption coeffcient was measured using the impedance tube and was modeled using both the Johnson-Champoux-Allard and the Attenborough models. The fndings show that the samples with a thickness of 55 mm and a density of 175 kg/m3 have the highest sound absorbing performance. The acoustic behavior of this new material was investigated in a reverberation room. Moreover, the acoustic performance of the panels in a conference hall was modeled, assessing the improvements in its reverberation time (RT), early decay time (EDT), speech transmission index (STI), clarity (C80), and defnition (D50). Finally, this paper shows that the acoustic performance of this material can be used to enhance room acoustics properties. 1. Introduction In the last two decades, noise pollution has been emerging as a sig- nifcant environmental concern to public health. The implementation of stringent noise pollution measures, together with increasing awareness of the harmful effects of noise, has promoted the use of sound absorbers in the construction and building industries [1,2]. Currently, various sound-absorber materials such as mineral wools, synthetic fbers, and polymeric foams are used in building and construction sectors. Gener- ally, these synthetic and mineral materials provide higher sound ab- sorption and thermal insulation and better fre-retardant properties than natural fbers. However, these materials are costly as they are predom- inantly derived from petroleum-based resources, and consequently, they contribute to adverse environmental effects such as global warming and climate changes [3–5]. These problems have attracted both researchers’ and industries’ attention to develop cost-effective and environmentally-friendly sound-absorbing construction materials. Nat- ural fbers are relatively low cost, biodegradable, easily available, eco-friendly, and show good sound absorption characteristics [6–8]. Some researchers have used vegetative and animal fbers such as cotton, fax, kenaf, sisal, coir, wool, etc. [9–13], and some have used agricul- tural by-products and wastes [14–17] as natural sound-absorbing materials. Soltani et al. [18] investigated the normal-incidence sound absorp- tion coeffcient (SAC) of yucca fbers. The SAC of the yucca peak for specimens with thicknesses of 15 and 35 mm was observed at fre- quencies of 2000 and 4000 Hz. Da Silva et al. [19] examined the sound absorption performance of specimens prepared from sisal, coconut, and sugarcane. The specimen made from sugarcane fbers gave higher acoustic absorption values than the sisal and coconut husk. The acoustic characteristics of sound absorbers made from raw palm empty fruit bunch (EFP) were investigated by Or et al. [20]. The results showed that at the frequency ranges above 1000 Hz, the average SAC of 0.9 is ach- ieved. Berardi and Iannace [21] investigated some vegetative and ani- mal natural fbers’ acoustic characteristics, such as kenaf, sugar cane, wool, and coir. They pointed to the potential application of these fbers * Corresponding author. E-mail address: uberardi@ryerson.ca (U. Berardi). Contents lists available at ScienceDirect Journal of Building Engineering journal homepage: www.elsevier.com/locate/jobe https://doi.org/10.1016/j.jobe.2021.102752 Received 15 April 2021; Received in revised form 8 May 2021; Accepted 17 May 2021