Impulse responses are great for recreating spaces, whether it is a resonant glass bottle or a large cave. Here’s a handy a trick for sculpting your own impulse responses, and therefore your own reverbs, from something that we spend a lot of time getting rid of — noise!
If you listen to an impulse response by itself, you’ll find that it has noise-like qualities, except the frequency response changes over time. This isn’t surprising as sine sweeps and pistol shots are representations of bursts of noise.
For the examples below, I’ve used Logic’s Space Designer, but this technique is possible with any convolution reverb. The white noise samples were processed in Logic, bounced out as a wav file and then dropped into Space Designer’s interface. [Space Designer's dry level was set to 0dB and wet level to -6dB with filter and volume envelopes bypassed]
Here’s an example of a white noise sample that was about 1.5 seconds long with an exponential fade out. The samples below include the dry noise sample (watch your speaker/headphone level) followed by the convolved output (apologies for the rather sad drum loop).
The Open Acoustic Impulse Response (Open AIR) Library is an amazing resource for sound designers to share acoustical data, and most of the content on this site is released under Creative Commons licenses.
(CC BY 2.0) OiMax
By Karen Collins
Adapted from a forthcoming article in Animation: An Interdisciplinary Journal
An often overlooked aspect of sound design is the use of sound to create a sense of identification for the audience. Just as with using point-of-view with camera angles, sound can be used to create an auditory position for the listener/audience, putting them “there” in the space, creating an emotional response and empathy, or distancing them from the action.
Auditory perspective is constructed by a variety of techniques that create or reinforce the physical sense of space for the listener through the use of spatialized sound. These techniques combine physical acoustics with psychoacoustics (the perceptual aspects of our response to sound). For example, the perceived location of a sound can appear to emanate from between two loudspeakers, in what is referred to as a “phantom image”. The techniques commonly used to create and reinforce a sense of acoustic space for the listener including microphone placement, loudspeaker placement, and digital signal processing effects.
Guest Contribution by Dr Tom Garner
This article addresses contemporary concepts regarding how we attune to sound within a fear context and discusses the potential impact of these ideas upon sound design, specifically with regards to evoking disorientation in survival horror computer games. Relevant theory is distilled to consider an ecological perspective of sound experience within a survival horror game context. We then discuss how this approach will likely impact upon future practice as we, as designers, strive to develop sound production and implementation techniques that have increasingly greater potential to unnerve, panic and otherwise terrify even the most hardcore of gamers.
A project funded by the EU is taking on the challenge of modelling, synthesizing and analysing acoustic reverberation. The DREAMS (Dereverberation, Reverberation of Audio, Music and Speech) project began in February 2013 and is expected to run for three years. The research initiative is being led by the Katholieke Universiteit Leuven (Belgium), and will focus on four areas seen as pivotal to our understanding and experience of (de-)reverberation: room acoustics; signal processing; psychoacoustics; speech and audio processing. And although the research itself is pretty technical it is expected that the findings could lead to improvements in a whole range of audio outputs and devices, such as tablets, mobile phones, etc. But will it fix the perennial problem of PA announcements at train stations?