Signal Processing Framework for Virtual Headphone Listening Tests in a Noisy Environment

A signal processing framework is introduced to enable parallel evaluation of headphones in a virtual listening test. It is otherwise impractical to conduct a blind comparison of several headphones. The ambient noise isolation capability of headphones has become an important design feature, since the mobile usage of earphones takes place in noisy listening environments. Therefore, the proposed signal processing framework allows a noise signal to be fed through a filter simulating the ambient sound isolation at the same time when music is played. This enables the simultaneous evaluation of the timbre and background noise characteristics, which together define the total headphone listening experience. Methods to design FIR filters for compensating the reference headphone response and for simulating the frequency response and isolation curve of the headphones to be tested are presented. Furthermore, a real-time test environment implemented using Matlab and Playrec is described.