Skip navigation
Skip navigation

Obliquely Truncated Simple Horns: Idealized Models for Vertebrate Pinnae

Fletcher, Neville H.; Thwaites, Suszanne

Description

The acoustical behaV:iour of simple horns of parabolic, conical and exponential profile is analyzed and explicit expressions are given for the impedance coefficients Zii. Wavefront curvature effects are included and the discussion is extended to investigate the effect of oblique truncation, which gives the horn a shape closely similar to that of a typical vertebrate pinna. The effects of higher modes.are discussed qualitatively and the conditions under which these can be neglected are...[Show more]

dc.contributor.authorFletcher, Neville H.
dc.contributor.authorThwaites, Suszanne
dc.date.accessioned2020-11-04T23:14:58Z
dc.date.available2020-11-04T23:14:58Z
dc.identifier.issn1610-1928
dc.identifier.urihttp://hdl.handle.net/1885/213627
dc.description.abstractThe acoustical behaV:iour of simple horns of parabolic, conical and exponential profile is analyzed and explicit expressions are given for the impedance coefficients Zii. Wavefront curvature effects are included and the discussion is extended to investigate the effect of oblique truncation, which gives the horn a shape closely similar to that of a typical vertebrate pinna. The effects of higher modes.are discussed qualitatively and the conditions under which these can be neglected are outlined. All horns are shown to act as efficient pressure transformers over only a restricted bandwidth, the limits of which are determined by flare rate and mouth diameter. For a horn with throat area S1 and mouth area S2 the maximum blocked-throat pressure gain is 10log10 (4 S2/S1) decibels; the gain reduces to 0 dB _at low frequencies and may become negative at very high frequencies. Oblique truncation raises the maximum gain above that of a horn truncated normally with the same minimum throat-to-mouth distance. It also moves the axis of maximum acoustic response away from the geometric axis of the horn towards the normal to the oblique mouth. This shift is large at low frequencies, becomes slightly nega;pefe at mid frequencies, and approaches zero at high frequencies. Use of these results .in the analysis of model auditory systems is outlined.
dc.format.mimetypeapplication/pdf
dc.language.isoen_AU
dc.publisherEuropean Acoustics Association
dc.rights© 1988 European Acoustics Association
dc.sourceActa Acustica united with Acustica
dc.titleObliquely Truncated Simple Horns: Idealized Models for Vertebrate Pinnae
dc.typeJournal article
local.description.notesThe author was affiliated with CSIRO when the paper was published
local.identifier.citationvolume65
dc.date.issued1988
local.publisher.urlhttps://acta-acustica.edpsciences.org/
local.type.statusPublished Version
local.contributor.affiliationFletcher, N. H., Department of Electronic Materials Engineering, The Australian National University
local.bibliographicCitation.issue4
local.bibliographicCitation.startpage194
local.bibliographicCitation.lastpage204
dcterms.accessRightsOpen Access
dc.provenancehttps://v2.sherpa.ac.uk/id/publication/23848..."The Published Version can be archived in any website" from SHERPA/RoMEO site (as at 5/11/2020).
CollectionsANU Research Publications

Download

File Description SizeFormat Image
Fletcheretal1988.pdf1.01 MBAdobe PDFThumbnail


Items in Open Research are protected by copyright, with all rights reserved, unless otherwise indicated.

Updated:  19 May 2020/ Responsible Officer:  University Librarian/ Page Contact:  Library Systems & Web Coordinator