Quantifying the perceptual value of lexical and non-lexical channels in speech

Stimuli page for work appearing in Interspeech 2023

Abstract:

Speech is a fundamental means of communication that can be seen to provide two channels for transmitting information: the lexical channel of which words are said, and the non-lexical channel of *how* they are spoken. Both channels shape listener expectations of upcoming communication; however, directly quantifying their relative effect on expectations is challenging. Previous attempts require spoken variations of lexically-equivalent dialogue turns or conspicuous acoustic manipulations. This paper introduces a generalised paradigm to study the value of non-lexical information in dialogue across unconstrained lexical content. By quantifying the perceptual value of the non-lexical channel with both accuracy and entropy reduction, we show that non-lexical information produces a consistent effect on expectations of upcoming dialogue: even when it leads to poorer discriminative turn judgements than lexical content alone, it yields higher consensus among participants

Stimuli:

We provide the full sets of stimuli constructed from the Switchboard corpus along with their associated ratings here .

The Qualtrics survey (constructed using https://github.com/CSTR-Edinburgh/qualtreats) was presented to participants through Prolific Academic.

Examples of our presentation in the lexical condition are included below. Additionally, we provide an example stimulus in the acoustic condition through this link.

A lexical stimuli: A lexical check question: