Figure 1
From: Artificial sounds following biological rules: A novel approach for non-verbal communication in HRI
The categories of the artificial sounds across three levels of complexity. In each category the basis of the sound (sine wave or pulse train) is followed by the changed parameters in parenthesis. Level 1 category 1: Simple sine wave; Level 2 category 2: Pulse train; category 3: Sine wave sounds with pitch contour down; category 4: Sine wave sounds with pitch contour up; category 5: Variable sine wave; Level 3 category 6: Complex pulse train sounds with pitch contour down; category 7: Complex pulse train sounds with pitch contour up.
