Why stress position bias?

There is ample evidence in the literature that English and Dutch listeners tend to perceive stress on the word-initial syllable. This bias is most easily seen in the perception of (nonsense) words containing repetitions of identical syllables. In four experiments the possible causes of this bias are investigated. The results show that the bias disappears when (i) words are preceded by a spoken context, when (ii) the voice source is replaced by noise (whisper), or when (iii) the fundamental frequency level of the utterance as a whole is lowered. The data are best explained by assuming that the listener interprets the onset of voicing of an isolated word as a (silent) pitch rise from the bottom of the speaker's pitch range.