The 5th International Conference on Acoustics and Vibration (ISAV2015) follows four previous conferences which were successfully held in Tehran in 2011 to 2014. The previous conferences were all well received by experts in acoustics and vibration and showed that there is a great interest in Iran for this important and vital field of science. The 5th International Conference on Acoustics and Vibration (ISAV2015) is jointly held by the Iranian Society of Acoustics and Vibration (ISAV) and the University of Tehran from 25-26 November 2015 in Tehran. ISAV2015 will provide an international forum for presentation and exchange of the latest scientific achievements and technological developments in the fields of acoustics and vibration. The program will feature plenary and keynote presentations, contributed oral and poster papers, a specialized commercial exhibition, and a number of technical workshops. A student competition for selection of the best BSc, MSc and PhD theses in acoustics and vibration is another exciting part of ISAV2015. On behalf of the organizing committee, it is a great pleasure for me to invite you to participate in this special event. We look forward to seeing you in Nov. 2015 in Tehran at ISAV2015.