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Biomedical subjects

R S Bolia

Publications and source records attributed to R S Bolia.

6 recordsLinked to original sources
PubMed2001

Effects of CIC hearing aids on auditory localization by listeners with normal hearing.

An experiment was conducted to determine the effects of completely-in-the-canal (CIC) hearing aids on auditory localization performance. Six normal-hearing listeners localized a 750-ms broadband noise from loudspeakers ranging in azimuth from -180 degrees to +180 degrees and in elevation from -75 degrees to +90 degrees. Independent variables included the presence or absence of the hearing aid and the elevation of the source. Dependent measures included azimuth error, elevation error, and the percentage of trials resulting in a front-back confusion. The findings indicate a statistically significant decrement in localization acuity, both in azimuth and elevation, occasioned by the wearing of CIC hearing aids. However, the magnitude of this decrement was small compared to those typically caused by other ear-canal occlusions, such as earplugs, and would probably not engender mislocalization of real-world sounds.

Adult↗
PubMed2001

Auditory localization under sustained +Gz acceleration.

The ability to localize a virtual sound source in the horizontal plane was evaluated under varying levels of sustained (+Gz) acceleration. Participants were required to judge the locations of spatialized noise bursts in the horizontal plane (elevation 0 degrees) during exposure to 1.0, 1.5, 2.5, 4.0, 5.5, and 7.0 +Gz. The experiment was conducted at the U.S. Air Force Research Laboratory's Dynamic Environment Simulator, a three-axis centrifuge. No significant increases in localization error were found between 1.0 and 5.5 +Gz; however, a significant increase did occur at the 7.0 +Gz level. In addition, the percentage of front/back confusions did not vary as a function of +Gz level. Collectively, these results indicate that the ability to localize virtual sound sources is well maintained at various levels of sustained acceleration. Actual or potential applications include the incorporation of spatial audio displays into the human-computer interface for vehicles that are operated in acceleration environments.

Acceleration↗
PubMed2001

Effects of hearing protectors on auditory localization in azimuth and elevation.

An experiment was conducted to determine the effects of two types of hearing protectors on auditory localization performance. Six listeners localized a 750-ms broadband noise from loudspeakers ranging in azimuth from -180 degrees to +180 degrees and in elevation from -75 degrees to +90 degrees. Independent variables included the type of hearing protector and the elevation of the source. Dependent measures included azimuth error, elevation error, and the percentage of trials resulting in a front-back confusion. Performance on each of the dependent measures was found to be mediated by one or more of the independent variables. Actual or potential applications include the generation of improved design guidelines for hearing protectors and workplace alarms.

Adolescent↗
PubMed2000

The effects of hearing protectors on auditory localization: evidence from audio-visual target acquisition.

Response times (RT) in an audio-visual target acquisition task were collected from 3 participants while wearing either circumaural earmuffs, foam earplugs, or no hearing protection. Analyses revealed that participants took significantly longer to locate and identify an audio-visual target in both hearing protector conditions than they did in the unoccluded condition, suggesting a disturbance of the cues used by listeners to localize sounds in space. RTs were significantly faster in both hearing protector conditions than in a non-audio control condition, indicating that auditory localization was not completely disrupted. Results are discussed in terms of safety issues involved with wearing hearing protectors in an occupational environment.

Adult↗
PubMed1999

Aurally aided visual search in three-dimensional space.

We conducted an experiment to evaluate the effectiveness of spatial audio displays on target acquisition performance. Participants performed a visual search task with and without the aid of a spatial audio display. Potential target locations ranged between plus and minus 180 degrees in azimuth and from -70 degrees to +90 degrees in elevation. Independent variables included the number of visual distractors present (1, 5, 10, 25, 50) and the spatial audio condition (no spatial audio, free-field spatial audio, virtual spatial audio). Results indicated that both free-field and virtual audio cues engendered a significant decrease in search times. Potential applications of this research include the design of spatial audio displays for aircraft cockpits and ground combat vehicles.

Adult↗