1. 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)

2. 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

3. 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

4. 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

5. Room Acoustics What is the goal? What are the constraints?
Classroom/Office: communication
Concert hall: ‘warm’ sound, rich acoustics
What are the constraints?
Room size
Varies reverberation time
Classroom ideal >0.5 s (play demos)
Concert Hall ideal 1.2 – 1.8 s (play demos)
First reflection >0.4 s
Correlates with attenuation of signal
High ceiling increases reverberation time, but diminishes intensity
Solution: diffusion rafters

6. 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 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

7. Thank You for your Time!