The semantic associations of acoustic parameters commonly used in the design of auditory information and warning signals.

Two experiments are described in which the effects of acoustic parameters, and changes in those acoustic parameters, on the salience of 42 pre-selected adjectives are explored. In experiment 1 four sets of seven stimuli each varying only along one of the four acoustic parameters pitch, speed, inharmonicity and rhythm were scaled along the 42 adjectives. Parameter-adjective associations showing significant effects both in terms of consistency (Kendall's W') and in linear mapping (regression) numbered 7 for pitch, 3 for speed, 2 for inharmonicity and 1 for rhythm. Three of the four parameters produced significant levels of both consistency and linear mapping for the adjective 'urgent'. In the second experiment, the overall meaning of complete within-parameter stimulus sets were explored and many differences both within and between parameters and adjectives were found. The results were used to design five trend monitoring sounds for helicopter flight, three of which are described in detail in this paper.