Acoustic Stress and Topic Detection in American English Spoken Sentences

The relationship between acoustic stress and information content of words is investigated. On one side, the average acoustic stress is measured for each word throughout each utterance. On the other side an Information Retrieval (IR) index, based on the words frequency throughout the particular spoken sentence and throughout the collection of analyzed spoken sentences, is calculated. The scatter plots of the two measures (average acoustic stress on the y-axis and IR index on the x-axis) show higher values of average acoustic stress with the increasing of the information measure of the word in the majority of the analyzed utterances. A statistically more valid proof of such a relationship is derived from the histogram of the words with high average acoustic stress vs. the IR index. This connrms that a word with high average acoustic stress has also a high value of the IR index.