Acoustic, semantic and phonetic influences in spoken warning signal words

Abstract

Three experiments are reported which explore the relationship between semantic, acoustic and phonetic variables in the judgement of eight warning signal words. Experiment 1 shows that listeners can distinguish very clearly between urgent and non-urgent versions of the words when spoken by real speakers, and that some signal words such as 'deadly' and 'danger' score more highly than words such as 'attention' and 'don't'. It also shows that the three dimensions of perceived urgency, appropriateness and believability of these words are highly correlated. Experiment 2 replicates Experiment 1 using synthesized voices where acoustic variables are controlled. The semantic effects are replicated, and to some extent appropriateness and believability are found to function differently from that of perceived urgency. Experiment 3 compares the same set of eight signal words with a set of phonetically similar neutral words, showing that warning signal words are rated significantly higher, and largely maintain their previous rank ordering.

Speech Tactons Improve Speech Warnings for Drivers

“…Additionally, it was found that an urgent utterance of the messages resulted in louder sounds, with higher pitch and pitch range. Edworthy et al [8] extended these findings, observing that signal words spoken urgently are perceived as more urgent, believable and appropriate as well. In our study, we use the above guidelines in the warnings, matching the urgency of the utterances to the urgency of the signified events.…”

“…These results also further support the claim that participants valued more being warned about important events and can further justify why higher ratings of annoyance for L H messages were acceptable according to participants' comments, while for L L they were not. This also relates to [8], where highly urgent messages were perceived as more appropriate. As a guideline, warnings of high criticality can be more alerting even at the cost of more annoyance.…”

Language-based multimodal displays for the handover of control in autonomous cars

“…Baldwin [2] also observed lower reaction times to urgent words, presented with higher signal intensity. Edworthy et al [3] found that urgently spoken signal words were perceived as more urgent and appropriate.…”

Speech warnings: a review

“…This may influence their relative urgency when spoken as compared to when in written form. Edworthy et al (2003b) found that when using synthesized voices, some words were rated has having lower levels of perceived urgency than research on text or natural speech presentations of the same words had suggested. These tended to be words that were difficult to voice with emphasis; 'lethal' and 'warning' in particular were rated lower than would be expected.…”