Is Natural Necessary? Human Voice versus Synthetic Voice for Intelligent Virtual Agents
Abstract
:1. Introduction
2. Related Work
2.1. Anthropomorphism and Co-Presence
2.2. Anthropomorphism and Congruence
3. Methodology
3.1. Study Design and Materials
3.2. Recruitment, Instruments, and Procedure
4. Results
4.1. Study-Related Stress
4.2. Social Co-Presence
4.3. Character Likeability and Voice Eeriness
4.4. Trustworthiness, Trust, and Working Alliance
4.5. Behavior Change Intention
5. Discussion
6. Limitations, Future Work, and Conclusions
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
References
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Group | Female | Male | Total |
---|---|---|---|
TTS | 44 | 15 | 59 |
Recorded | 36 | 23 | 59 |
Total | 80 | 38 | 118 |
Group | Stress Level Before Interaction | Stress Level After Interaction | Paired Samples t-Test (Before vs. After) | |||
---|---|---|---|---|---|---|
Mean | SDT | Mean | SDT | t | p | |
TTS | 6.51 | 1.746 | 5.86 | 1.634 | 3.703 | <0.001 |
Recorded | 7.24 | 1.675 | 5.64 | 1.836 | 7.707 | <0.001 |
Items | Recorded | TTS | ||
---|---|---|---|---|
Mean | SDT | Mean | STD | |
I did not want a deeper relationship with the agent * | 2.37 | 0.981 | 2.32 | 0.973 |
I wanted to maintain a sense of distance between us * | 2.95 | 0.753 | 2.73 | 0.827 |
I was unwilling to share personal information with the agent * | 3.31 | 1.178 | 3.36 | 0.905 |
I wanted to make the conversation more intimate | 2.74 | 0.965 | 2.71 | 1.001 |
I tried to create a sense of closeness between us | 2.66 | 0.843 | 2.64 | 0.846 |
I was interested in talking to the agent | 3.22 | 0.966 | 3.25 | 1.03 |
Average | 2.88 | 0.599 | 2.84 | 0.540 |
Measure | Recorded | TTS | ||
---|---|---|---|---|
VA’s likeability (the construct) | 0.380 | 0.003 | 0.511 | <0.001 |
Dislike—Like | 0.482 | <0.001 | 0.486 | <0.001 |
Unfriendly—Friendly | 0.201 | 0.127 | 0.402 | 0.002 |
Unkind—Kind | 0.058 | 0.663 | 0.258 | 0.048 |
Unpleasant—Pleasant | 0.225 | 0.086 | 0.350 | 0.007 |
Awful—Nice | 0.303 | 0.020 | 0.398 | 0.002 |
VA’s voice impression (the construct) | 0.176 | 0.181 | −0.301 | 0.020 |
Reassuring—Eerie | −0.375 | 0.003 | −0.356 | 0.006 |
Numbing—Freaky | −0.095 | 0.473 | −0.400 | 0.002 |
Ordinary—Supernatural | −0.146 | 0.270 | −0.127 | 0.337 |
Bland—Uncanny | 0.113 | 0.392 | 0.104 | 0.431 |
Unemotional—Hair-raising | 0.042 | 0.751 | 0.025 | 0.849 |
Uninspiring—Spine-tingling | 0.381 | 0.003 | −0.045 | 0.735 |
Predictable—Thrilling | 0.367 | 0.004 | 0.103 | 0.437 |
Boring—Shocking | 0.359 | 0.005 | 0.143 | 0.280 |
Construct | #Items | Recorded | TTS | ||||
---|---|---|---|---|---|---|---|
NA | Mean | STD | NA | Mean | STD | ||
Trustworthiness | |||||||
Ability | 5 | 0 (0%) | 3.30 | 0.794 | 0 (0%) | 3.28 | 0.622 |
Benevolence * | 2 | 0 (0%) | 3.25 | 1.001 | 0 (0%) | 2.87 | 0.940 |
Integrity | 2 | 0 (0%) | 3.72 | 0.665 | 0 (0%) | 3.82 | 0.700 |
Trust | 4 | 0 (0%) | 2.95 | 0.884 | 4 (2%) | 2.85 | 0.682 |
Working Alliance | |||||||
Task | 4 | 15 (6%) | 2.76 | 1.169 | 5 (2%) | 2.84 | 0.928 |
Goal | 4 | 24 (10%) | 2.81 | 1.230 | 11 (5%) | 2.79 | 0.859 |
Bond | 4 | 51 (22%) | 3.01 | 1.105 | 42 (18%) | 2.75 | 1.103 |
Behavior | VA-Recorded | VA-TTS | ||||||
---|---|---|---|---|---|---|---|---|
Before Interaction | After Interaction | Paired Sample t-Test | Before Interaction | After Interaction | Paired Sample t-Test | |||
Mean (STD) | Mean (STD) | t(58) | p | Mean (STD) | Mean (SDT) | t(58) | p | |
Participate in a study group | 2.15 (1.00) | 2.42 (0.95) | −2.734 | <0.01 | 2.05 (1.01) | 2.54 (0.97) | −3.959 | <0.001 |
Do physical activity | 2.34 (1.21) | 2.39 (1.05) | −1.524 | 0.133 | 2.31 (1.24) | 2.54 (1.15) | −2.188 | 0.033 |
Meet new people | 2.66 (0.99) | 2.83 (0.95) | −0.369 | 0.713 | 2.68 (0.99) | 2.88 (1.00) | −1.651 | 0.104 |
Consume caffeinated food/drink | 3.51 (1.15) | 3.00 (1.17) | 5.046 | <0.001 | 3.54 (1.10) | 2.93 (1.17) | 5.788 | <0.001 |
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Abdulrahman, A.; Richards, D. Is Natural Necessary? Human Voice versus Synthetic Voice for Intelligent Virtual Agents. Multimodal Technol. Interact. 2022, 6, 51. https://doi.org/10.3390/mti6070051
Abdulrahman A, Richards D. Is Natural Necessary? Human Voice versus Synthetic Voice for Intelligent Virtual Agents. Multimodal Technologies and Interaction. 2022; 6(7):51. https://doi.org/10.3390/mti6070051
Chicago/Turabian StyleAbdulrahman, Amal, and Deborah Richards. 2022. "Is Natural Necessary? Human Voice versus Synthetic Voice for Intelligent Virtual Agents" Multimodal Technologies and Interaction 6, no. 7: 51. https://doi.org/10.3390/mti6070051