Open Journal of Acoustics, 2013, 3, 31-35 http://dx.doi.org/10.4236/oja.2013.32005 Published Online June 2013 (http://www.scirp.org/journal/oja) The Effect of Television Decors on the Change of Reverberation Time of the Studio Mohsen Karami, Masoumeh Shafieian Department of Media Engineering, IRIB University, Tehran, Iran Email: mohsenkarami.ir@gmail.com, shafieian@iust.ac.ir Received January 1, 2013; revised February 2, 2013; accepted February 10, 2013 Copyright © 2013 Mohsen Karami, Masoumeh Shafieian. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. ABSTRACT Reverberation time within studio’s decor is changed because of addition of its surface to the overall surfaces of the stu- dio and also the additional absorption of its materials. It seems reverberation time changes due to studio’s decor is little because surface of the decor is small in comparison with the overall surfaces of the studio and surface has an important role in room constant and therefore in reverberation time. But these changes do not only depend on added surfaces and their absorption. Reverberation time is also dependent on shape of the decor and sometimes. It can decrease the effects of added surfaces which are used to increase the reverberation time. In this paper, a standard television studio is de- signed and implemented by using ODEON and 12 different decor which their dimensions and materials are similar to the actual ones, are applied inside the studio. Then studio’s decor effects on reverberation time of the studio are com- puted, compared and analyzed. Keywords: TV Studio; TV Decors; Reverberation Time; Coefficient of Absorption 1. Introduction The time that is needed in order that the sound level from 60 dB above the threshold of hearing reach to the hearing level. This is the definition that was released by Sabin in 1895 and functions as an important factor in recognition of the acoustic property of the rooms yet. RT 1 is one of most important factors in studying the quality of sound in studio and it has different amounts according to the size and its function. Reverberation time in one octave fre- quency bands is measured from 63 Hz to 8000 Hz. The number that is given as the reverberation time of the room is actually the numerical average of reverberation time in frequencies of 500 and 1000 Hz. This method is based on ISO3382 standard that has been considered in this essay. Two other factors can be extracted from re- verberation time which shows the way of reverberation time in low and high frequencies and its ratio to rever- beration time in intermediate frequency and therefore the warmth or sharpness of sound in environment. These parameters are BR and TR which are described with the Equation (1). RT is the reverberation time and its fol- lowing number refers to its frequency [1,2] BR 2 = RT125 RT RT500 RT   500 1000 TR 3 = RT1000 RT2000 RT 0   (1) rt ha RT500 100 Researches on the effects of decors on sound are mainly about conce lls stages. Their goal was to pro- vide better acoustic conditions for musicians and trans- mitting good sound to the audience. In 1976, Nakayama researched about reflective elements role in the stage and found out that these elements on ceiling and rear wall can preserve the acoustical conditions of the hall in the stage and this can enhance the sound homogeneity. He also pointed out that it is necessary to use reflective surfaces and strong diffusers on lateral, rear walls and if possible on ceiling [3]. In 2004, Kahle and Katz researches show- ed that to control absorption of sound energy it is needed to use absorption in stage decors and these absorbers are better to be on the rear wall. They don’t mention ab- sorber material and its frequency [4]. According to configuration of TV decors, there is no need to transmit sound to the outside the décor. So find- ing absorbing material with adequate frequency behavior has an important role in controlling sound inside decor. In this paper, we have investigated the influence of TV 2 Bass ratio. 3 Treble ratio. 1 Reverberation time. Copyright © 2013 SciRes. OJA