A Psychoacoustic-Based Analysis of the Impact of Pre-Echoes and Post-Echoes in Soundfield Rendering Applications

Abstract:
In this paper we propose two metrics for the evaluation of the impact of pre-echoes and post-echoes on the perceived quality in soundfield rendering applications. These metrics are derived from psychoacoustic-based considerations, in particular the masking effect, well known in the literature of perceptual coding. The measurement is accomplished through a virtual microphone array that samples the soundfield on a circumference. The soundfield within the circle is estimated by means of the circular harmonic decomposition. As a result, space-time impulse responses of the rendering system are obtained, which are then analyzed through the masking curve to extract the pre- and post-echoes metrics. A comparison between experimental and simulative results, conducted using the same setup, allows to discriminate the impact of the adopted rendering engine and of the non-idealities of the real system (environment and loudspeakers) on pre- and post-echoes. Index Terms — Loudspeaker array, Circular Harmonic Decomposition, Pre-echoes, Post-echoes