A study is reported in which it is shown that observers can useat least three types of acoustics variables that indicate reliablywhen a moving sound source is passing: interaural temporal differences,the Doppler effect, and amplitude change. Each of these variableswas presented in isolation and each was successful in indicatingwhen a (simulated) moving sound source passed an observer. Thesethree variables were put into competition (with each indicatingthat closest passage occurred at a different time) in an effortto determine their relative importance. It was found that amplitudechange dominated inteaural temporal differences which, in turn,dominated the Doppler effect stimulus variable. The results arediscussed in terms of two interpretations. First, it is possiblethat subjects based their judgments on the potential discriminabilityof each stimulus variable. However, because the stimuli used involvedeasily discrimable changes, subjects may instead have based theirjudgments on the independence of a stimlus variable from differentenvironmental situation conditions. The dominance ordering obtainedsupports the second interpretation.
Rosenblum, L.D., Wuestefeld, A.P.,and Saldaña, H.M (1993). Auditory Looming Perception: Influenceson Anticipatory Judgments. Perception. 22, 1467-1482.
Several studies in the auditory perception literature hint thatlisteners may be able to anticipate the time of arrival of anapproaching sound source (Rosenblum, L D, Carello, C, Pastore,R E, 1987; Schiff, W, Oldak, R, 1990). In two experiments listenersjudged the time of arrival of an approaching car based on variousportions of its auditory signal. Subjects pressed a computer keyto indicate when the car would have just passed them assumingthe car maintained a constant approach velocity. A number of variableswere tested including (a) the time between the offset of the signaland the virtual time of passage (b) duration of the signal (c)feedback concerning judgment accuracy. Results indicate that increasingthe time between signal offset and virtual time of passage decreasesjudgment accuracy while the actual duration of the signal hadno significant effect. Feedback significantly improved performanceoverall.
Rosenblum, L.D. (1993). Acousticalinformation for controlled collisions. In A. Schick (Ed.), Contributionsto Psychological Acoustics. Oldenburg, Germany: Bibliotheks- undInformationssystem der Carl von Ossietzky Universität Oldenburg.
From the ecological approach to perception, all behavior can beunderstood as the control of collisions with objects of the environment.It is incumbent on the ecological psychologist to understand theprospective information which allows an animal to anticipate upcomingcollisions. In this chapter, prospective acoustic informationfor controlled collisions is discussed borrowing from work onvisual time-to-arrival information. Potential acoustic dimensionswhich might specify time-to-arrival are surveyed. Two specificexamples of auditorily-controlled collisions are examined: 1)a moving observer approaching a stationary surface, and 2) a loomingobject approaching a stationary observer. The research conductedon these two scenarios is reviewed along with conjectures abouttheir informational support.
Rosenblum, L.D., Wuestefeld, A.P.,and Anderson, K.L. (1996). Auditory reachability: An affordanceapproach to the perception of sound source distance. EcologicalPsychology. 8(3), 1-24.
The literature on perception of sound source distance revealsa wide range of listener accuracy. Most experiments have listenersperform unintuitive tasks, using unnatural sounds presented inimpoverished acoustic environments. The present experiments implementan affordance paradigm for which listeners judge the 'reachability'of a natural, live sound source in a familiar acoustic environment.Results reveal that listeners are quite accurate in judging whetherthe source is reachable and are sensitive to the advantage affordedby two vs. one degree of freedom reaches. Further analyses revealthat when scaled to an intrinsic bodily dimension, judgment differencesbetween listeners disappear, implicating intrinsically scaledspecificational information. A follow-up experiment explores thepotential informational support for these judgments testing theusefulness of head movements and binaural hearing. Results revealthat whereas head movements had no bearing on either judgmentaccuracy or consistency, binaural information did enhance listenerconsistency. This could suggest that the allometric relation betweeninteraural distance and arm length might provide a basis for auditoryreachability judgments.
Wuestefeld, A.P. & Rosenblum, L.D.(1996). Perceptual learning in an auditory time to arrival task.University of California, Riverside Cogntive Science TechnicalReport #UCR.96.011
The present research examines accuracy in an auditory time toarrival task when performance feedback is first provided to listenersand is subsequently withdrawn. Previous research testing visualtime to arrival suggests that while performance feedback improvesaccuracy, this improvement is not maintained after feedback iswithdrawn. While these findings are supportive of a Cognitiveapproach to looming perception, they are not supportive of anEcological approach which predicts a retention of performanceupon feedback withdrawal. In an effort to determine which approachbest construes the perceptual learning occurring for auditorytime to arrival tasks, listeners were provided with feedback whichwas then withdrawn. Listeners made judgments about the time toarrival of an approaching car based on various portions of theevent. Subjects participated in three experimental sessions onconsecutive days. The experimental group received no feedbackduring the first session, feedback during the second session,and no feedback during the final session. When feedback was withdrawn,the higher performance level attained during training was retained.These results support the Ecological approach to perceptual learningin auditory time to arrival tasks.
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