The relationship between localization and the Franssen effect

Abstract

The relationship between localization and the Franssen effect was studied for noise and tones in a sound-deadened and in a live room. The noise was wideband and the tones were 250, 500, 1000, 1500, 2500, and 4000 Hz. Listeners were asked to determine the location of the stimuli in a localization task and to discriminate the difference between a pair of stimuli used to generate the Franssen illusion and a steady-state tone in a Franssen-effect discrimination task. Poor performance in the Franssen-effect discrimination task is consistent with the stimulus conditions leading to a strong Franssen illusion. Poor performance in both the Franssen effect and localization tasks was obtained for midfrequency tones (near 1500 Hz) and in the live room. Thus, the Franssen illusion is strongest for a live room and for midfrequency tones consistent with the difficulty listeners have in localizing sounds under these conditions. These results are consistent with those of Hartmann and Rakerd [J. Acoust. Soc. Am. 86, 1366-1373 (1989)] and support their suggestion of a correlation between the Franssen effect and localization in rooms.

Monkey Sound Localization: Head-Restrained versus Head-Unrestrained Orienting

“…The FE is strongest for tonal stimuli of ϳ1-1.5 KHz, which are difficult for humans to localize because of ambiguities in the physical cues used for localization (Hartmann and Rakerd, 1989;Yost et al, 1997),…”

“…It was hypothesized that if the monkeys experienced the FE, they should orient to the source of the transient component of the stimuli, where cats orient to when presented with similar stimuli (Dent et al, 2004), and humans report to hear the sustained component of the stimuli in the context of a discrimination task (Yost et al, 1997).…”

“…To extend our understanding of the spatial auditory abilities of the rhesus monkey, two of the subjects in this study, Glenn and Shepard, were tested with acoustic stimuli of the type known to evoke the perception of the FE in humans (Hartmann and Rakerd, 1989;Yost et al, 1997) and cats (Dent et al, 2004). The FE (Franssen, 1962) is an auditory illusion created by presenting singletone stimuli from speakers located symmetrically about the midline, on the horizontal plane; in the experiments reported here, the sources were located at (Ϯ31°, 0°).…”

“…The FE is an auditory illusion in which a long-duration, slowly rising single-tone stimulus presented from one side of the subject is perceived on the opposite side, at the location of the presentation of an abruptly rising, short-duration tone (Franssen, 1962;Hartmann and Rakerd, 1989;Yost et al, 1997). The stimuli were constructed as in Dent et al (2004), who showed that cats perceive this auditory illusion.…”

Threshold of the precedence effect in noise

“…This onset capture effect observed in lateralization studies is reminiscent of the well-known Franssen effect (Franssen, 1962;Yost et al, 1997;Hartmann and Rakerd, 1989;Dent et al, 2007). In the Franssen effect, an abruptlygated pure tone is separated into the onset transient part, which is presented from one loudspeaker, and the steadystate tonal part presented from another loudspeaker.…”