Two rectangular 1/3-octave passbands were derived from different spectral regions of everyday sentences, with the intelligibility of one band approximately twice the others. Both passbands were then filtered to produce a series of narrower rectangular passbands. Each of the original 1/3-octave passbands in turn served as the fixed bandwidth “pedestal” and was paired with each of the series of narrower passbands of the other band. Remarkably, dual band intelligibilities were the same, regardless of which band served as pedestal, so the summed bandwidths determined intelligibility: The summed intelligibilities were irrelevant. Implications of this paradoxical “summed bandwidth rule” are discussed.
Received 14 March 2013Accepted 02 July 2013Published online 15 July 2013
The project described was supported by Award Number R01DC000208 from the National Institute on Deafness and Other Communication Disorders. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institute on Deafness and Other Communication Disorders or the National Institutes of Health.
Article outline: I. Introduction II. Methods A. Subjects B. Stimulus preparation III. General procedure A. Experiment 1: Intelligibility of dual band stimuli with 4-semitone pedestals B. Results for experiment 1 C. Experiment 2: Testing the validity of the summed bandwidth rule for narrow rectangular passbands D. Results for experiment 2 E. Experiment 3: Intelligibility of dual band stimuli with 12-semitone pedestals F. Results for experiment 3 IV. Summary and discussion
Richard M. Warren,
James A. Bashford Jr. and
Peter W. Lenz
Source:J. Acoust. Soc. Am. 134, EL244 (
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