Page 220 - Designing Sociable Robots

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Expressive Vocalization System 201

anger
600
Utterance: 400
"It's been moved already"
200
0
0 50 100 150
calm disgust
600 600
400 400

200 200
0 0
0 50 100 150 0 50 100 150
fear happy
600 600
400 400
200 200
0 0
0 50 100 150 0 50 100 150
sad surprise
600 600
400 400

200 200
0 0
0 50 100 150 0 50 100 150
Figure 11.3
Pitch analysis of Kismet’s speech for the English phrase “It’s been moved already.”

Happy speech is relatively fast, with a high mean pitch, wide pitch range, and wide pitch
•
variance. It is loud with smooth undulating inflections as shown in figure 11.3.
• Disgusted speech is slow with long pauses interspersed. It has a low mean pitch with a
slightly wide pitch range. It is fairly quiet with a slight creaky quality to the voice. The
contour has a global downward slope as shown in figure 11.3.

• Surprised speech is fast with a high mean pitch and wide pitch range. It is fairly loud with
a steep rising contour on the stressed syllable of the final word.
Human Listener Experiments

To evaluate Kismet’s expressive speech, nine subjects were asked to listen to prerecorded
utterances and to fill out a forced-choice questionnaire. Subjects ranged from 23 to 54 years