Human Factors Design

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Human Factors Design

• Upcoming
• Today CPD (final TLA)
• Tues Dec 7 Extra office hours (3-5 pm)
• Wed Dec 8 Quizette 4 (Last day of Class)
• Fri Dec 10 Paper (4 pm CCIT 4015)

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Thinking of a Career in Human Factors Design?

• Major Areas of Acoustic Research
• Alarms and Sirens
• Train horn, Car alarm, Alarm clock
• Auditory Spatial Display
• Sonification for the blind, auditory enhancement
  of complicated visual environments
• Consumer product advertising
• Earcons and auditory icons
• Room design
• Home theatre systems, concert halls, classrooms

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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

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Room Acoustics

• What is the goal?
• Classroom/Office communication
• Concert hall warm sound, rich acoustics
• What are the constraints?
• Room size
• Varies reverberation time
• Classroom ideal gt0.5 s (play demos)
• Concert Hall ideal 1.2 1.8 s (play demos)
• First reflection gt0.4 s
• Correlates with attenuation of signal
• High ceiling increases reverberation time, but
  diminishes intensity
• Solution diffusion rafters

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Specific Challenges of the Room

• Materials
• Concrete in schools
• Solid for building/long-term
• Poor acoustics lots of reverb muddying the
  sound
• People
• 80 of concert hall sound is absorbed by the
  audience
• Sources of background noise
• Ventilation systems
• Cheaper systems have noisier fans
• Typical classroom 50 dB background noise
• Speech 60-65 dB at source, diminishes 3 dB every
  meter
• Back of room (4 meters) SNR 1 dB
• Outside noise (concert hall)
• Traffic and noise of city
• Solution acoustic tiling

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Thank You for your Time!