Journal article
Statistics of natural reverberation enable perceptual separation of sound and space
Proceedings of the National Academy of Sciences - PNAS, Vol.113(48), pp.E7856-E7865
11/29/2016
DOI: 10.1073/pnas.1612524113
PMCID: PMC5137703
PMID: 27834730
Abstract
In everyday listening, sound reaches our ears directly from a source as well as indirectly via reflections known as reverberation. Reverberation profoundly distorts the sound from a source, yet humans can both identify sound sources and distinguish environments from the resulting sound, via mechanisms that remain unclear. The core computational challenge is that the acoustic signatures of the source and environment are combined in a single signal received by the ear. Here we ask whether our recognition of sound sources and spaces reflects an ability to separate their effects and whether any such separation is enabled by statistical regularities of real-world reverberation. To first determine whether such statistical regularities exist, we measured impulse responses (IRs) of 271 spaces sampled from the distribution encountered by humans during daily life. The sampled spaces were diverse, but their IRs were tightly constrained, exhibiting exponential decay at frequency-dependent rates: Mid frequencies reverberated longest whereas higher and lower frequencies decayed more rapidly, presumably due to absorptive properties of materials and air. To test whether humans leverage these regularities, we manipulated IR decay characteristics in simulated reverberant audio. Listeners could discriminate sound sources and environments from these signals, but their abilities degraded when reverberation characteristics deviated from those of real-world environments. Subjectively, atypical IRs were mistaken for sound sources. The results suggest the brain separates sound into contributions from the source and the environment, constrained by a prior on natural reverberation. This separation process may contribute to robust recognition while providing information about spaces around us.
Details
- Title: Subtitle
- Statistics of natural reverberation enable perceptual separation of sound and space
- Creators
- James Traer - Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139 jtraer@mit.eduJosh H McDermott - Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139
- Resource Type
- Journal article
- Publication Details
- Proceedings of the National Academy of Sciences - PNAS, Vol.113(48), pp.E7856-E7865
- DOI
- 10.1073/pnas.1612524113
- PMID
- 27834730
- PMCID
- PMC5137703
- NLM abbreviation
- Proc Natl Acad Sci U S A
- ISSN
- 0027-8424
- eISSN
- 1091-6490
- Publisher
- National Academy of Sciences; United States
- Grant note
- name: James S. McDonnell, award: Scholar Award; DOI: 10.13039/100000055, name: HHS | NIH | National Institute on Deafness and Other Communication Disorders, award: R01DC014739; DOI: 10.13039/100000055, name: HHS | NIH | National Institute on Deafness and Other Communication Disorders, award: F32DC013703-03
- Language
- English
- Date published
- 11/29/2016
- Academic Unit
- Psychological and Brain Sciences; Iowa Neuroscience Institute
- Record Identifier
- 9984065373702771
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