Intended carefulness for voiced warning signal words

Design standards for print warnings (e.g., signs and labels) recommend the use of signal words to convey the presence and level of a hazard. However, very little research has been conducted on the use of signal words presented auditorily. In the present study, 43 voiced signal words were examined as a function of several factors: voice style (monotone, emotional, whisper), sound level (low, high), participant group (college students, community volunteers) and gender of the speaker and the participant. Results indicated that auditory presentation yielded a pattern of connoted hazard levels (ratings of intended carefulness) similar to previous research using visual presentation. Emotional voicing produced significantly higher carefulness ratings than monotone or whisper voicing (with overall sound level held constant). Female speakers produced significantly higher carefulness ratings than male speakers. Implications for the design of speech warnings are discussed.