en Audiology Audiology Original Research Original Research <p><strong>Background: </strong>Many elderly individuals complain of difficulty in understanding speech in noise despite having normal hearing thresholds. According to previous studies, auditory training leads to improvement in speech-in-noise perception, but these studies did not consider the etiology, so their results cannot be generalized. The present study aimed at investigating the effectiveness of envelope-based interaural time difference (ITD ENV) localization training on improving ITD threshold and speech-in-noise perception.<br> &nbsp;&nbsp; <strong>Methods:</strong> Thirty-two elderly males aged 55 to 65 years with clinically diagnosed normal hearing at 250-2000 Hertz, who suffered from speech-in-noise perception difficulty participated in this study. These individuals were randomly divided into training and control groups:&nbsp; 16 elderlies in the experimental group received envelope-based interaural time difference localization training in 9 sessions, but 16 matched elderlies in the control group did not receive any training. The ITD ENV threshold and spatial word recognition score (WRS) in noise were analyzed before and after the localization training.<br> <strong>&nbsp;&nbsp; Results:</strong> Findings demonstrated that following the training program, the interaural time difference envelope threshold and spatial word recognition score (WRS) in noise were improved significantly in the experimental group (p&le; 0.001). Moreover, a significant difference was detected in interaural time difference envelope threshold and spatial word recognition score (WRS) in noise (p&le; 0.001) before and after the training in the experimental group.<br> &nbsp;&nbsp; <strong>Conclusion:</strong> The results of the present study revealed the effectiveness of envelope- based interaural time difference localization training in localization ability and speech in noise perception in the elderlies with normal hearing up to 2000 Hz who suffered from speech-in-noise perception difficulty.<br> &nbsp;</p> <div> <div><div id="_com_3" uage="JavaScript"></div></div> </div> <p></p> Interaural Time Difference, Training, Speech-in-Noise Perception, Localization 207 212 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-1716-3&slc_lang=en&sid=1 Maryam Delphi delphi.maryam1@gmail.com 200319475328460033726 200319475328460033726 No Department of Audiology, University of Social Welfare and Rehabilitation Sciences, Tehran & Musculoskeletal Rehabilitation Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran. Yones Lotfi yones1333@gmail.com 200319475328460033727 200319475328460033727 Yes Department of Audiology, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran. Abdollah Moossavi amoossavi@gmail.com 200319475328460033728 200319475328460033728 No Department of Otolaryngology and Head and Neck Surgery, School of Medicine, Iran University of Medical sciences, Tehran, Iran. Enayatollah Bakhshi bakhshi@razi.tums.ac.ir 200319475328460033729 200319475328460033729 No Department of Biostatistics, University of Social Welfare and Rehabilitation Scienc-es, Tehran, Iran. Maryam Banimostafa banimostafa.maryam@gmail.com 200319475328460033730 200319475328460033730 No Department of Biomedical Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran.