Currently used procedures in room acoustics measurements are not automated. Particularly in medium-sized and large areas they require a lot of time and intensive labour which directly translates into an increase in the measurement cost. Introduction of an automated system would increase efficiency of the measurements, and therefore could present both practical and scientific benefit. The paper presents initial feasibility study for designing a system that permits the measurement of selected acoustic parameters for any choice of three-dimensional grid of measurement points throughout the volume of the room. The system will utilize an autonomous probe attached to a blimp, and will be able to measure and analyze acoustic characteristics of the rooms. The article discusses the initial choices of the system elements, starting from the general idea, through the mechanical design and control procedures, the software that controls positioning and flying of the probe, up to the automation of the measurement procedure and its possible impact on the acoustic field.

Reflecting structures placed over the stage in auditoria and concert halls should provide sound reflection in a way that enhances sound emission from the stage without causing acoustic defects in the interior. Model studies conducted by the authors were used to determine the relative level of sound reflection by reflecting structures as a function of frequency for a number of geometric configurations and materials. Analysis of the results allowed drawing conclusions about the effect of modifications of the ceiling over the reflecting panels on the quality of the sound reflected from them. It was shown that modification of the ceiling over the reflecting panels by employing highly sound absorbing materials significantly improved the characteristics of the reflected sound. Also, certain configurations of elements located in the space under the ceiling should be avoided, as the experiments indicated the occurrence of adverse acoustic effects.

Sound diffusers, in particular those based on changes in the phase of the reflected wave (Schroeder diffusers), have recently gained greatly in popularity in acoustics as an effective means to eliminate defects and improve the acoustic performance of interiors. This paper draws attention to a possibility of shaping acoustic parameters of sound diffusers and fundamental errors made in applying diffusers. Also, an often neglected issue of sound absorption by diffusers has been tackled. The presented results of laboratory measurements indicate a great significance of the diffusers' rigidity and geometry on their absorption coefficient at low frequencies. The effect of arrangement of elements on the diffusion coefficient was analysed for two types of elements based on the prime number N = 7.