Testing Auditory Displays

1
Testing Auditory Displays

• Katie Parmeson
• October 28th, 2003

2
Effects of Earplugs and Protective Headgear on
Auditory Localization Ability in the Horizontal
Plane

• Nancy L. Vause, D. Wesley Grantham (1999)

3
Overview

• Sound localization on a horizontal plane while
  wearing protective headgear
• Questions addressed
• What are the individual effects with the 1)Kevlar
  helmet, 2)E-A-R earplug, 3)ER25 earplug
• What are the combined effects of the Kevlar
  helmet with each of the separate earplugs
• Tested 8 conditions

4
Task

• Tested two orientations
• Front
• Side 90
• 80 stimulus (4 of each 20 positions) per run, 3
  runs each participant
• Verbally selecting loud speaker number
• Researcher would enter data

5
Results

• Lateral orientation (90) yielded front/back
  confusion
• Ear plugs
• Ear plugs with Kevlar helmet
• Not a significant difference between the
  bare-head and Kevlar helmet condition.
• 25 increase in error for frontal orientation on
  Kevlar, EAR and ER25, but only significant for
  ER25????

6
Application of a Three-Dimensional Auditory
Display in a Flight Task

• Adelbert W. Bronkhorst, J. A. (Hans) Veltman, Leo
  van Breda

7
Overview

• Directional auditory information
• Auditory signals used along with visual radar
  cues to locate targets
• Concerned with front/back and up/down confusion

8
Three-Dimensional Auditory Displays

• Advantages
• Natural sound localization
• Spatial separation of signal and noise
• Assigning spatial positions to sound sources
• Limitations of COTS
• Only on Windows/PC
• Not distributed architecture
• No standard API

9
Task

• Follow a target until it disappears
• Relocate target
• Conditions tested
• No-display
• Auditory display
• Visual display
• Auditory visual display
• Dependent variables
• Search time
• Subjective workload

10
Results

• Sound produced by the virtual source should have
  a relatively long duration and head movements
  should be allowed. (Bronkhorst 1995)
• Virtual sources were more difficult than real
  sources to localize
• Performance improved with the use of multiple
  modalities

11
Efficient and Effective Use of Low-Cost 3D Audio
Systems

• Kenneth Wang, Venkataraman Sundareswaran, Clemet
  Tam, Philbert Bangayan (2002)

12
Overview

• Commercial, off-the-shelf 3D sound cards
• Decrease visual display clutter by utilizing
  auditory cues, 3D audio spatialization
• Interaural time difference
• Interaural intensity difference
• Spectral cues
• Developed 3D audio server

13
Task

• Three phases
• Pre-test phase
• Training phase
• Post-test phase
• Participant indicated location of sound by
  orienting their head

14
Results

• The training period had a lasting effect of at
  least 4 days

15
Evaluating the Effectiveness of Spatial Audio
Displays in a Simulated Airborne Command and
Control Task

• W. Todd Nelson, Robert S. Bolia

16
Overview

• Speech spatialization
• Enhance speech intelligibility
• Compensate for degrading effects of noise
• Lower the perceived mental effort of simultaneous
  speech streams

17
Task

• Listen for Baron then mark down following Color
  and number combination
• Rate perceived mental workload using the NASA
  Task-Load Index
• Mental demand
• Physical demand
• Temporal demand
• Performance
• Effort
• Frustration

18
Results

• Contradictory results
• failed to indicate any main effects or
  interactions involving the SPATIAL AUDIO factor
• the main effect for SPATIAL AUDIO was found to
  approach statistical significance
• No significant differences in the Workload
  analysis