Download An Acoustic Paintbrush Method for Simulated Spatial Room Impulse Responses Virtual reality applications require all kinds of methods to create
plausible virtual acoustics environments to enhance the user experience. Here, we present an acoustic paintbrush method that modifies
the timbre of a simple room acoustics simulation with the timbre
of a measured room response while aiming to preserve the spatial
aspects of the simulated room. In other words, the method only
applies the measured spectral coloration and alters the simulated
and temporal distribution of early reflections as little as possible.
Three variations of the acoustic paintbrush method are validated
with a listening test. The results indicate that the method works
reasonably well. The paintbrushed room acoustic simulations were
perceived to become closer to the measured room acoustics than
the source simulation. However, the limits of the perceived effect
varied depending on the input signal and the simulated and recorded
responses. This warrants for further perceptual testing.
Download Fade-in Control for Feedback Delay Networks In virtual acoustics, it is common to simulate the early part of a
Room Impulse Response using approaches from geometrical acoustics and the late part using Feedback Delay Networks (FDNs). In
order to transition from the early to the late part, it is useful to
slowly fade-in the FDN response. We propose two methods to control the fade-in, one based on double decays and the other based
on modal beating. We use modal analysis to explain the two concepts for incorporating this fade-in behaviour entirely within the
IIR structure of a multiple input multiple output FDN. We present
design equations, which allow for placing the fade-in time at an
arbitrary point within its derived limit.