Ecological Acoustics and Human Factors Design

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Ecological Acoustics and Human Factors Design

• Upcoming
• Mon Dec 6 CPD (final TLA)
• Wed Dec 8 Quizette 4 (Last day of Class)
• Fri Dec 10 Paper (4 pm CCIT 4015)

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Perceived Urgency

• Urgency corresponds to close sounds
• Higher Frequencies
• Why is this urgent?
• Attenuated over distance, audible when close
• Higher Intensities
• Why is this urgent?
• Attenuated over distance, more acoustic energy
  when close
• Greater Spectral distortion
• Why is this urgent?
• Ripple noise pitch distorts timbre when close

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Alarm Design

• Alarm and horn design
• Alarm purpose
• Maximum urgency long-term localization
• Design to compliment need
• Example Train horn vs. Fog horn
• Train horn Train approaching (demo)
• Need for high urgency
• Loud sounds disturb communities
• Engineers get hearing loss
• Choose peak frequency/pitch combo for loudness
  (560 Hz New horn)
• Fog Horn Land is near (demo)
• Need for medium urgency
• Sound attenuation with water, mountains, etc
• No intensity limit if horn aimed at sea
• Choose low frequency to maintain sound over
  distance

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Ambulance Siren

• Maximum Urgency
• Designed to attract and hold attention (demo old)
• Obstacles
• Attenuation of high frequency sound
• Vary siren over frequency range
• Increases high frequency content, stimulates
  loudest range
• Loud Buzzer broadband punctuation
• Separation from background noise (demo new)
• Louder than background noise
• Varying signal
• Multiple signal patterns to maintain attention
• Problems with alarms
• Startle response
• Elicit panic, unclear behavioral ramification
• Prevents communication
• Loud alarm masks speech
• Provokes self response
• Turn off the /??! alarm

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Auditory Spatial Attention

• How many sounds can be distinguished?
• Can sounds be used to guide action?
• Auditory Spatial Use of sound to guide action
• Maximum 6 auditory objects
• Separated in space and pattern
• Use Gestalt auditory streaming rules to group
  objects
• PLAY DEMOS

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How are Auditory Spatial Displays Used

• Sonification for the blind
• Transpose visual information to non-visual format
• Represents all visual information
• Used in isolation of other components
• Visual enhancement
• Improve reaction time
• Auditory cues to stimulate nystagmus
• Wider azimuth of awareness
• Capture attention to spatial area
• Change focus of user
• Alert user to additional steps, information
• Cockpit environment

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Marketing Auditory Display

• Earcons Auditory Icons
• Auditory icons Ecologically valid cue for object
• E.g., Cow Moo
• Earcons Artificial cue for object
• E.g., Intel Demo
• Why use earcons?
• Increase exposure of company
• Use of multiple modalities to improve
  memorability of product
• Blind, low-vision access
• Increasingly aged population with reduced visual
  capacity
• Temporal control
• Ensure attention to company identification at
  correct moment
• Recency/primacy effects
• Non-invasive acoustic display to capitalize on
  memory constraints

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Earcon or Auditory Icon

• Memorability of a picture
• Experiment Present picture with icon or earcon
  (Lemmens et al, 2001)
• Categorization of objects
• Learn to match earcon/icon to stimulus
• Accompany stimulus presentation with sound
• Reaction times faster with auditory icon
• Slower with Earcon
• Memorability of a sound
• Experiment Match sound to picture
• Varied directness of relationship
• Ecological (Auditory icon) occur together in
  nature
• Metaphorical (Earcon) referent to object
• Mouse to non-Mouse squeaking
• Random (Earcon) referent to object
• All sounds equally memorable
• Ecological and metaphorical better facilitate
  object memory