Ermous developing electronic techlogy has brought telecommunication huge popularity. Users love to be connected all the time everywhere to the network or Internet through Mobile Ad-hoc Network (MANET), UMTS and WiMAX etc. MANET is considered as self-configured unlike des creating infrastructure-less network connected by Wireless Network; des can exchange data packets without a central control. For beyond line of sight (BLOS) communication, MANET can be an intelligent selection. However, to maintain quality of service (QoS), more or less challenges still have to be resolved. Multimedia as well as VoIP gaining massive popularity as the internet world favored by the huge use of Wireless Network. In this thesis, routing protocols (RP) OLSR, DSR and TORA have been employed for voice traffic as they maintaining dissimilar characteristics in unlike situations as Wireless Network factors like; bandwidth, signal strength, network traffic or load, network size influencing the voice quality. This thesis work focusing on the impact of de mobility influencing voice quality in unlike Routing Protocol's performance. To decide the best suit RP, the OPNET Simulator 16.0 has been used.