Auditory efferents facilitate sound localization in noise in humans.

The mammalian auditory system contains descending neural pathways, some of which project onto the cochlea via the medial olivocochlear (MOC) system. The function of this efferent auditory system is not entirely clear. Behavioral studies in animals with olivocochlear (OC) lesions suggest that the MOC serves to facilitate sound localization in noise.

Localization of virtual sound at 4 Gz.

Introduction: Acceleration directed along the body's z-axis (Gz) leads to misperception of the elevation of visual objects (the "elevator illusion"), most probably as a result of errors in the transformation from eye-centered to head-centered coordinates. We have investigated whether the location of sound sources is misperceived under increased Gz.

Method: Visually guided localization responses were made, using a remotely controlled laser pointer, to virtual auditory targets under conditions of 1 and 4 Gz induced in a human centrifuge.

Hearing thresholds during Gz acceleration with masking noise.

Background: Future fighter aircraft will include three-dimensional sound signals as part of the human-machine interface. The reduction in cerebral vascular flow associated with maneuvering acceleration (+Gz) may affect a pilot's ability to perceive and interpret such aural cues. We hypothesized that vascular deprivation along the cochlea produced by +Gz would raise hearing thresholds either globally or specifically at 1000 Hz.

Judging the urgency of nonvocal auditory warning signals: perceptual and cognitive processes.

Previous research has identified acoustic properties modulating the perceived urgency of alarms. The authors conducted 3 experiments using a multidimensional approach in which participants made acoustic dissimilarity judgments and urgency dissimilarity judgments for pairs of sequences. Experiment 1 confirmed the validity of acoustic parameters in urgency perception of experimental alarms.