The influence of auditory feedback on speed choice, violations and comfort in a driving simulation game

Two experiments are reported which explore the relationships between auditory feedback (engine noise), speed choice, driving violations and driver comfort. Participants played a driving simulation game with different levels of auditory feedback in the form of engine noise. In Experiment 1, a between-subjects design revealed that no noise and low levels of engine noise (65 dB(A)) resulted in participants driving at faster speeds than in the medium (75 dB(A)) and high (85 dB(A)) levels of engine noise conditions. The low noise feedback conditions were also associated with decreases in driver comfort. Experiment 2 also demonstrated that low levels of engine noise feedback (no feedback and 70 dB(A)) were associated with increases in driving speed, and driving violations relative to higher levels of feedback (75 dB(A) and 80 dB(A)). Implications exist for current car manufacturing trends which emphasise a growing increase in noise insulation for the driver.     

On the stability of the arousal strength of warning signal words

Studies are reported that demonstrate the stability of scales of the arousal strength of warning signal words. We demonstrate that these scales are not an artefact of the measurement technique employed, nor are they influenced by the effects of experimental context. In addition, we generalize previous findings on the arousal strength of signal words to the UK population. Separate studies revealed a high level of agreement in signal word arousal strengths derived from magnitude estimation, category estimation, and cross‐modality matching. In addition, the relative arousal strengths of signal words were shown to be independent of the composition of the warning stimulus set. These findings suggest that arousal strength scales of signal words are robust and that signal words can be used with confidence to achieve hazard matching between the hazard inherent in a product/situation and the hazard implied by the associated warning. Copyright © 2000 John Wiley & Sons, Ltd.     

Acoustic,semantic and phonetic influences in spoken warning signal words

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. Copyright © 2003 John Wiley & Sons, Ltd.     

What determines auditory similarity? The effect of stimulus group and methodology

Two experiments on the internal representation of auditory stimuli compared the pairwise and grouping methodologies as means of deriving similarity judgements. A total of 45 undergraduate students participated in each experiment, judging the similarity of short auditory stimuli, using one of the methodologies. The experiments support and extend Bonebright's (1996) findings, using a further 60 stimuli. Results from both methodologies highlight the importance of category information and acoustic features, such as root mean square (RMS) power and pitch, in similarity judgements. Results showed that the grouping task is a viable alternative to the pairwise task with N > 20 sounds whilst highlighting subtle differences, such as cluster tightness, between the different task results. The grouping task is more likely to yield category information as underlying similarity judgements.