Analysis of the room acoustic texture parameters in function of diffusers location and distribution inside a small concert hall

To study the room acoustic texture, defined through a group of parameters derived from the cumulative energy in time of the early reflections temporal information, different room configurations inside a small concert hall with fixed room volume were analyzed. The proposed texture parameters are the expected texture (ETx), the mixing time (Mt) and the distance between models (DBM) of the monaural impulse responses. The cases consisted in: a) six configurations with constant diffusers surface extension positioned at different locations on the lateral walls, b) three configurations with ceiling, lateral, rear and front walls set at the same acoustic condition, i.e. reflective, absorptive and diffusive, and c) constant surface extension of just one wall with different coatings. For this, a series of monaural impulse responses (RIRs) registered at ESPRO (IRCAM) were processed. For case a) texture parameters remain almost constant through all variations; b) Although ETx showed higher values in the diffusive condition compared to the reflective condition, Absolute DBM showed a more appropriate values for the reflective and absorptive conditions. For case c) spatial average ETx shows no significant improvement of adding one diffusive wall from the fully reflective one.