Perceptual implications of different Ambisonics-based methods for binaural reverberation.

Reverberation is essential for the realistic auralisation of enclosed spaces. However, it can be computationally expensive to render with high fidelity and, in practice, simplified models are typically used to lower costs while preserving perceived quality. Ambisonics-based methods may be employed to this purpose as they allow us to render a reverberant sound field more efficiently by limiting its spatial resolution.

A multimedia speech corpus for audio visual research in virtual reality (L).

Virtual reality environments offer new possibilities in perceptual research, such as presentation of physically impossible but ecologically valid stimuli in contrived scenarios. To facilitate perceptual research in such environments, this study presents a publicly available database of anechoic audio speech samples with matching stereoscopic and 360° video. These materials and accompanying software tool allow researchers to create simulations with up to five talkers positioned at arbitrary azimuthal locations, at multiple depth planes, in any 360° or stereoscopic environment.

Acoustic visualizations using surface mapping.

Sound visualizations have been an integral part of room acoustics studies for more than a century. As acoustic measurement techniques and knowledge of hearing evolve, acousticians need more intuitive ways to represent increasingly complex data. Microphone array processing now allows accurate measurement of spatio-temporal acoustic properties.

Concert halls with strong lateral reflections enhance musical dynamics.

One of the most thrilling cultural experiences is to hear live symphony-orchestra music build up from a whispering passage to a monumental fortissimo. The impact of such a crescendo has been thought to depend only on the musicians' skill, but here we show that interactions between the concert-hall acoustics and listeners' hearing also play a major role in musical dynamics. These interactions contribute to the shoebox-type concert hall's established success, but little prior research has been devoted to dynamic expression in this three-part transmission chain as a complete system.

Design and outcomes of an acoustic data visualization seminar.

Recently, the Department of Media Technology at Aalto University offered a seminar entitled Applied Data Analysis and Visualization. The course used spatial impulse response measurements from concert halls as the context to explore high-dimensional data visualization methods. Students were encouraged to represent source and receiver positions, spatial aspects, and temporal development of sound fields, frequency characteristics, and comparisons between halls, using animations and interactive graphics.

Echo thresholds for reflections from acoustically diffusive architectural surfaces.

When sound reflects from an irregular architectural surface, it spreads spatially and temporally. Extensive research has been devoted to prediction and measurement of diffusion, but less has focused on its perceptual effects. This paper examines the effect of temporal diffusion on echo threshold.

The role of diffusive architectural surfaces on auditory spatial discrimination in performance venues.

In musical or theatrical performance, some venues allow listeners to individually localize and segregate individual performers, while others produce a well blended ensemble sound. The room acoustic conditions that make this possible, and the psycho-acoustic effects at work are not fully understood. This research utilizes auralizations from measured and simulated performance venues to investigate spatial discrimination of multiple acoustic sources in rooms.