• Volume/Page
  • Keyword
  • DOI
  • Citation
  • Advanced
   
 
 
 

Journal of the Acoustical Society of America

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Previous Issue

Dec 2007

Volume 122, Issue 6, pp. 3133-EL235

Return to All Sections
back to top
RSS Feeds

The effect of hair on auditory localization cues

Bradley E. Treeby, Jie Pan, and Roshun M. Paurobally

J. Acoust. Soc. Am. Volume 122, Issue 6, pp. 3586-3597 (2007); (12 pages)

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Previous empirical and analytical investigations into human sound localization have illustrated that the head-related transfer function (HRTF) and interaural cues are affected by the acoustic material properties of the head. This study utilizes a recent analytical treatment of the sphere scattering problem (which accounts for a hemispherically divided surface boundary) to investigate the contribution of hair to the auditory cues below 5 kHz. The hair is modeled using a locally reactive equivalent impedance parameter, and cue changes are discussed for several cases of measured hair impedance. The hair is shown to produce asymmetric perturbations to the HRTF and the interaural time and level differences. The changes in the azimuth plane are explicated via analytical examination of the surface pressure variations with source angle. Experimental HRTFs obtained using a sphere with and without a hemispherical covering of synthetic hair show a good agreement with analytical results. Additional experimental and analytical investigations illustrate that the relative contribution of the hair remains robust, regardless of the placement of the pinnas, or inclusion of a cylindrical neck.
Show PACS
43.66.Ba Models and theories of auditory processes
43.66.Pn Binaural hearing
43.20.Fn Scattering of acoustic waves

Spectral integration and wideband analysis in gap detection and overshoot paradigms

Joseph W. Hall, III, Emily Buss, and John H. Grose

J. Acoust. Soc. Am. Volume 122, Issue 6, pp. 3598-3608 (2007); (11 pages) | Cited 1 time

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Several listening conditions show that energy remote from a target frequency can deleteriously affect sensitivity. One interpretation of such results entails a wideband analysis involving a wide predetection filter. The present study tested the hypothesis that both temporal gap detection and overshoot results are consistent with a wideband analysis, as contrasted with statistical combination of information across independent channels. For gap detection, stimuli were random or comodulated 50-Hz-wide noise bands centered on 1000, 1932, 3569, and 6437 Hz. For overshoot, the masker was an 8-kHz low-pass filtered noise, with 5-ms tone bursts presented at the same center frequencies used for gap detection. Signals were presented with either 0- or 250-ms delay after masker onset. In each paradigm, the target was introduced at only one frequency or at all four frequencies. Results from gap detection conditions did not favor a wideband analysis interpretation: Results in the random condition were consistent with an optimal combination of cues across frequency. An across-channel interference effect was also evident when only one of the four bands contained the gap. Although results from the overshoot conditions were consistent with a wideband analysis interpretation, they were more parsimoniously accounted for in terms of statistical combination of information.
Show PACS
43.66.Dc Masking
43.66.Ba Models and theories of auditory processes
43.66.Mk Temporal and sequential aspects of hearing; auditory grouping in relation to music

The Franssen effect illusion in budgerigars (Melopsittacus undulatus) and zebra finches (Taeniopygia guttata)

Micheal L. Dent, Elizabeth M. McClaine, and Thomas E. Welch

J. Acoust. Soc. Am. Volume 122, Issue 6, pp. 3609-3614 (2007); (6 pages) | Cited 2 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The properties of the Franssen effect (FE) were measured in budgerigars and zebra finches. To elicit the FE, listeners are presented with a signal which has been split into a transient component, carrying an abrupt onset and ramped offset and separated in space from the sustained component which has a slowly rising onset and longer duration. When these two signals are played under certain conditions, the perception is that of a long-duration steady state tone being played at the location of the transient. The birds were trained using operant conditioning methods on a categorization task to peck a left key when presented with a stimulus from a left speaker and to peck a right key when presented with a stimulus from a right speaker. Once training was completed, FE stimuli were presented during a small proportion of trials. The FE was measured at speaker separations of 60° and 180° in both echoic and echoic-reduced conditions. Both species of birds exhibited the FE, although to varying degrees, across conditions. These results show that nonmammals also experience the FE illusion in confusing listening situations in a manner similar to mammals, suggestive of similar auditory processing mechanisms.
Show PACS
43.66.Gf Detection and discrimination of sound by animals
43.66.Qp Localization of sound sources
43.66.Pn Binaural hearing
43.80.Lb Sound reception by animals: anatomy, physiology, auditory capacities, processing

Detection and discrimination of simple and complex sounds by hearing-impaired Belgian Waterslager canaries

Amanda M. Lauer, Robert J. Dooling, Marjorie R. Leek, and Kirsten Poling

J. Acoust. Soc. Am. Volume 122, Issue 6, pp. 3615-3627 (2007); (13 pages)

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Belgian Waterslager canaries (BWC) are bred to produce a distinctive low-pitched song with energy restricted to a lower range of frequencies than in other types of canaries. Previous studies have shown a high frequency hearing loss primarily above 2000 Hz that is related to hair cell abnormalities in BWC, but little is known about auditory perception in these birds. Here, frequency, duration, and intensity discrimination, temporal integration, gap detection, and discrimination of temporally reversed harmonic complexes in BWC were measured and compared to normal-hearing non-BWC. BWC had excellent frequency discrimination ability at 1000 Hz, but showed poor frequency discrimination compared to non-BWC at frequencies in the region of hearing loss. Duration and intensity discrimination were not adversely affected in BWC. Temporal integration was reduced in BWC, except at 2000 Hz. Gap detection and discrimination of temporally reversed stimuli were somewhat better in BWC than in non-BWC. Those tests that relied primarily on temporal processing were less affected by the cochlear damage in BWC than tests that probably relied more on audibility and spectral analysis. Thus, despite significant high frequency hearing loss and extensive damage along the basilar papilla, BWC retain relatively good hearing abilities under many conditions.
Show PACS
43.66.Gf Detection and discrimination of sound by animals
43.66.Sr Deafness, audiometry, aging effects
43.80.Lb Sound reception by animals: anatomy, physiology, auditory capacities, processing
43.66.Fe Discrimination: intensity and frequency

Discrimination of speaker sex and size when glottal-pulse rate and vocal-tract length are controlled

David R. R. Smith, Thomas C. Walters, and Roy D. Patterson

J. Acoust. Soc. Am. Volume 122, Issue 6, pp. 3628-3639 (2007); (12 pages) | Cited 3 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A recent study [ Smith and Patterson, J. Acoust. Soc. Am. 118, 3177–3186 (2005) ] demonstrated that both the glottal-pulse rate (GPR) and the vocal-tract length (VTL) of vowel sounds have a large effect on the perceived sex and age (or size) of a speaker. The vowels for all of the “different” speakers in that study were synthesized from recordings of the sustained vowels of one, adult male speaker. This paper presents a follow-up study in which a range of vowels were synthesized from recordings of four different speakers—an adult man, an adult woman, a young boy, and a young girl—to determine whether the sex and age of the original speaker would have an effect upon listeners’ judgments of whether a vowel was spoken by a man, woman, boy, or girl, after they were equated for GPR and VTL. The sustained vowels of the four speakers were scaled to produce the same combinations of GPR and VTL, which covered the entire range normally encountered in every day life. The results show that listeners readily distinguish children from adults based on their sustained vowels but that they struggle to distinguish the sex of the speaker.
Show PACS
43.66.Lj Perceptual effects of sound
43.71.Bp Perception of voice and talker characteristics
43.71.An Models and theories of speech perception

Perceptual thresholds for detecting modifications applied to the acoustical properties of a violin

Claudia Fritz, Ian Cross, Brian C. J. Moore, and Jim Woodhouse

J. Acoust. Soc. Am. Volume 122, Issue 6, pp. 3640-3650 (2007); (11 pages) | Cited 4 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
This study is the first step in the psychoacoustic exploration of perceptual differences between the sounds of different violins. A method was used which enabled the same performance to be replayed on different “virtual violins,” so that the relationships between acoustical characteristics of violins and perceived qualities could be explored. Recordings of real performances were made using a bridge-mounted force transducer, giving an accurate representation of the signal from the violin string. These were then played through filters corresponding to the admittance curves of different violins. Initially, limits of listener performance in detecting changes in acoustical characteristics were characterized. These consisted of shifts in frequency or increases in amplitude of single modes or frequency bands that have been proposed previously to be significant in the perception of violin sound quality. Thresholds were significantly lower for musically trained than for nontrained subjects but were not significantly affected by the violin used as a baseline. Thresholds for the musicians typically ranged from 3 to 6 dB for amplitude changes and 1.5%–20% for frequency changes. Interpretation of the results using excitation patterns showed that thresholds for the best subjects were quite well predicted by a multichannel model based on optimal processing.
Show PACS
43.66.Lj Perceptual effects of sound
43.75.Cd Music perception and cognition
43.75.De Bowed stringed instruments
43.66.Jh Timbre, timbre in musical acoustics

Within- and across-channel gap detection in cochlear implant listeners

John H. Grose and Emily Buss

J. Acoust. Soc. Am. Volume 122, Issue 6, pp. 3651-3658 (2007); (8 pages)

Full Text: Read Online (HTML) | Download PDF

Show Abstract
This study examined within- and across-electrode-channel processing of temporal gaps in successful users of MED-EL COMBI 40+ cochlear implants. The first experiment tested across-ear gap duration discrimination (GDD) in four listeners with bilateral implants. The results demonstrated that across-ear GDD thresholds are elevated relative to monaural, within-electrode-channel thresholds; the size of the threshold shift was approximately the same as for monaural, across-electrode-channel configurations. Experiment 1 also demonstrated a decline in GDD performance for channel-asymmetric markers. The second experiment tested the effect of envelope fluctuation on gap detection (GD) for monaural markers carried on a single electrode channel. Results from five cochlear implant listeners indicated that envelopes associated with 50-Hz wide bands of noise resulted in poorer GD thresholds than envelopes associated with 300-Hz wide bands of noise. In both cases GD thresholds improved when envelope fluctuations were compressed by an exponent of 0.2. The results of both experiments parallel those found for acoustic hearing, therefore suggesting that temporal processing of gaps is largely limited by factors central to the cochlea.
Show PACS
43.66.Mk Temporal and sequential aspects of hearing; auditory grouping in relation to music
43.66.Ts Auditory prostheses, hearing aids
Return to All Sections
Close

Home Publications Meetings Contact ASA Site Map Back to Top

Copyright © Acoustical Society of America

close