Commemorating 25 years of publication
Assessing human perception
M P Hollier and G Cosier
Network technology typically contains complex and nonlinear processes, such as low bit rate codecs for data reduction. This nonlinearity means that the perceived performance cannot be predicted with conventional engineering performance metrics. Reliable objective assessment of perceived performance is required for optimal design, commissioning and monitoring of quality. This paper looks at how BT can measure, optimise and control the perceived performance of the service that is provided. The final receiver of a signal is the human user - by modelling the senses of the human it is possible to predict whether an error would be perceptible. An auditory perceptual model has been developed and used to predict the subjective performance of a variety of nonlinear systems. Applications for the auditory model include design optimisation, as a measurement tool and as part of a nonlinear network planning tool. This paper focuses specifically on the auditory system, and how perceptual modelling is providing the basis for improved quality of voice service. However, as the global landscape adapts over the next decade, with multimedia, personal interactivity, and the concept of virtuality´ then all of the human senses need to be considered together. Future work is planned to include an elementary visual model and the combination of sensory models for the assessment of multimedia products and services.