Auditory traits of "own voice".

People perceive their recorded voice differently from their actively spoken voice. The uncanny valley theory proposes that as an object approaches humanlike characteristics, there is an increase in the sense of familiarity; however, eventually a point is reached where the object becomes strangely similar and makes us feel uneasy. The feeling of discomfort experienced when people hear their recorded voice may correspond to the floor of the proposed uncanny valley. To overcome the feeling of eeriness of own-voice recordings, previous studies have suggested equalization of the recorded voice with various types of filters, such as step, bandpass, and low-pass, yet the effectiveness of these filters has not been evaluated. To address this, the aim of experiment 1 was to identify what type of voice recording was the most representative of one's own voice. The voice recordings were presented in five different conditions: unadjusted recorded voice, step filtered voice, bandpass filtered voice, low-pass filtered voice, and a voice for which the participants freely adjusted the parameters. We found large individual differences in the most representative own-voice filter. In order to consider roles of sense of agency, experiment 2 investigated if lip-synching would influence the rating of own voice. The result suggested lip-synching did not affect own voice ratings. In experiment 3, based on the assumption that the voices used in previous experiments corresponded to continuous representations of non-own voice to own voice, the existence of an uncanny valley was examined. Familiarity, eeriness, and the sense of own voice were rated. The result did not support the existence of an uncanny valley. Taken together, the experiments led us to the following conclusions: there is no general filter that can represent own voice for everyone, sense of agency has no effect on own voice rating, and the uncanny valley does not exist for own voice, specifically.