The Contribution Of F0 To The Perception Of Interest By L1 And L2 English Speakers

This study investigates the effects of F0 on L1 and L2 English speakers’ perception of interest.Using an F0 manipulation paradigm,three groups of perceptual experiments were conducted where 11 L1 English speakers,12 L2 English speakers with higher English proficiency and 12 L2 English speakers with lower English proficiency were presented with the same set of F0-manipulated audio stimuli and then asked to rate how interested each audio stimulus sounded to them by using a semantic rating scale: [very disinterested--slightly disinterested--neutral--slightly interested--very interested].Four questions were supposed to be addressed: 1)How would the perceived degrees of interest vary with the mean F0 of the originally “interested” utterances downshifted? 2)Are there similarities or differences between L1 and L2 English speakers in their perceived degrees of interest toward the same set of audio stimuli? 3)How exactly would higher-proficient and lower-proficient L2 English speakers differ or resemble in their perceived degrees of interest toward the same set of stimuli? 4)Are there F0 distances between different categories of interest? If there are,how many semitones of F0 are there between them?Findings are as follows.1)The effects of F0 on the listeners’ perceived degrees of interest are significant: the higher F0 is,the more interested each stimulus sounds.This might be attributed to the activation of a set of bio-information dimensions implying the“dynamicity” relation of the speakers’ bodies: higher F0 suggests faster vibration rates of the vocal cords,thus creating an image of being “activated and vigorous” which can be accordingly perceived as “more interested”;while lower F0 suggests slower vibration rates of the vocal cords,thus creating an image of being “inanimate and less vigorous” which can be perceived as “less/dis interested”.2)No significant differences between L1 and L2 English speakers have been detected,which suggests that the decoding routines of “（dis）interest” relevant F0 cues can be universal.The reason might be that humans of different speech communities share the same set of bio-informational dimensions in using F0 to decode “（dis）interest”.3)Differences in English levels have not caused significant effects on the two L2 groups’ perception of interest,which can also be due to the “universal F0 decoding rules” as presupposed by the shared bio-informational dimensions.4)For L1 group,the acoustic F0 distance between[slightly interested] and [neutral] is 5 semitones;and that between [neutral] and [slightly disinterested] is 5 semitones.In L2（H）group,the F0 distance between [slightly interested] and [neutral] is 4 semitones;and that between [neutral] and [slightly disinterested] is 5 semitones.In L2（L）group,the F0 distance between [slightly interested] and [neutral] is 4 semitones while that between [neutral] and [slightly disinterested] is 6 semitones.Besides,this study has found that F0 contribution to“interestedness” is relatively limited.Simply by increasing or decreasing F0 values,a speaker cannot be perceived as sounding [very interested] or [very disinterested] to listeners.This suggests that the expression of a powerful emotion/attitude cannot be realized only through manipulations of F0.The current findings are of significance.Theoretically,this study has revealed that the decoding of F0 is still universal in the case of “（dis）interest”.This can be interpreted as empirical evidence supporting the BID hypothesis that humans might have universal prosodic performances in expressing an emotion or attitude.Practically,the F0 distances quantified in the perception experiments might have some implications for speech engineering,providing supports for the synthesis or recognition of affective speech.