The Acceptability and Comparative Study of DTMF and Speech for Banking Transactions in Nigeria

Aims: This article reports the development and the experimental results of the acceptability testing and comparison of speech and dual tone multi frequency (DTMF) for interacting with a speech application for carrying out banking transactions.
Study Design: A within-subjects experiment where each of the participants tested both the DTMF only and speech only modalities was carried out. Each one filled a questionnaire after testing each modality
Place and Duration of Study: Department of Computer and Information Sciences, Covenant University, Ota, Nigeria, between May 2013 and June 2013.
Methodology: Voice Objects 11 was used as the development platform. Voxeo Prophecy 9 was used as the implementation platform while MySQL 5.5 was used as the database management system for storing each customer's account details. X-Lite soft phone 3.3 was used for testing the system. 50 undergraduates of Covenant University, Ota, Nigeria participated in the evaluation. Each one tested the system using DTMF and speech separately. After each round of the tests, each one filled a questionnaire for the modality tested in a bid to measure the acceptability and user satisfaction with the modality.
Results: The entire system’s satisfaction ratings for DTMF were significantly higher (M=36.18) than for speech (M=34.76), t(49)= -1.46, tcrit =2.0, P=.05. For modality evaluation, speech was more satisfying (M=12.22) than DTMF (M=12.18), t(49)= 0.14, tcrit =2.0, P=.05. For modality entertainment, both speech and DTMF were rated equal (M=13.94), t(49)=0, tcrit =2.0, P=.05. For modality naturalness, speech was more natural (M=10.2) than DTMF (M=9.44), t(49)=-2.41, tcrit =2.0, P=.05. 52% of the subjects chose DTMF modality, whereas 48% chose speech (p = .05).
Conclusion: Dialogue systems are a widely acceptable technology for carrying out banking transactions in Nigeria. It will provide a cost-effective and easily accessible means of carrying out banking transactions.