Influence of Sender Parameters and Network Architecture on Perceived Audio Quality

Abstract

Network simulations and subjective testing have been used to evaluate the effects of frame lengths, packetization settings, and the advantages of using a Differentiated Services (DiffServ) network architecture for music streaming over Internet Protocol (IP) networks. The simulations show that using smaller packet sizes can result in lower packet loss ratios, even though the total bit rate is increased due to network overhead. The network architecture simulations show that DiffServ make the packet loss process less bursty when compared to the current Best Effort (BE) network architecture. These network simulations were followed up with a subjective test to investigate the effects more thoroughly. The subjective test combined three audio clips, three packet loss ratios (3%, 5%, 7%) and two Error Concealment (EC) algorithms with two packet loss processes. Results from the subjective test show statistically significant effects of audio clip, EC, and packet loss ratio on perceived audio quality as well as interaction effects between the network architectures and both audio clip and packet loss ratio. It was found that for a loss ratio of 3%, the loss pattern from a DiffServ network lead to a significantly higher perceived audio quality than the loss pattern from a BE network. However, for higher loss ratios no differences can be seen between the two network architectures.