The influence of speakers' speech quality on listeners' purchase intention

Abstract

Background

Personal selling involves a social interaction between salespeople and customers. The pragmatic skills and the verbal skills possessed by salespeople contribute to the development of their first impression as perceived by customers. This first impression is influential in determining the purchase intention. Among the different features of speech quality, high speech rate has been widely accepted to enhance both perceived personality and purchase intention. However, the ways that how speech rate were manipulated in previous studies varied greatly and whether two speech rates were perceptually different has not been addressed at all. Furthermore, the roles of how overall voice quality of salespeople plays on customers’ perception of speakers and customers’ ultimate purchase intention have always been neglected. A better understanding on how overall voice quality of the salespeople would affect customers’ purchase intention would definitely shed light on the importance of occupational vocal health and safety in the industry and sales techniques.

Objective

This thesis aimed to investigate the individual and combined effects of the speakers’ overall voice quality and speech rate on the listeners’ perception of the speakers’ personality and how that would affect the listeners’ purchase intention.

Method

A pilot study was first conducted to determine the just noticeable difference in speech rate perception and to identify the best representative samples of three different levels of overall voice quality. These formed the basis for later stimuli manipulation to be used in the Main Study. In the Main Study, three stimulus sets were synthesized. The first stimulus set was differed in overall voice quality only; the second stimulus set was differed in speech rate only; and the third stimulus set was differed in both factors. Forty university undergraduates or graduates were invited to rate their perception of the speakers’ personality and their own purchase intention after listening to the stimuli by using a five-point Likert scales on each of the four variables: perceived attractiveness, perceived competence willingness to listen further and willingness to make a purchase. The individual and combined effects of overall voice quality and speech rate on the four variables were computed by the Quade’s rank analysis of covariance. The ordinal logistic regression models were used to analyse the strengths of the effects.

Results

First, the findings showed that a deterioration on the speakers’ overall voice quality significantly lowered the listeners’ ratings on all four variables. Second, the speakers with non-manipulated speech rate (264 syllables per minute) were rated significantly higher on all four variables by the participants when compared to the speakers with noticeably faster or slower speech rates. Third, overall voice quality showed significantly greater effects than speech rate on all four variables. Last, perceived personality correlated highly and positively with purchase intention.

Conclusion

The studies from this thesis revealed the importance of the speakers’ overall voice quality over speech rate in influencing the listeners’ purchase intention. Employers from the personal selling industry should pay extra attention to occupational voice safety and health of the salesforce in order to achieve the best sales performance.