Head movements while recognizing speech arriving from behind.

Listeners' head movements were measured during speech recognition with simultaneous maskers. Both the target and masker were behind the listener, separated by 30°. Frequent head turns during speech recognition were observed for four of the ten listeners. For those four, head turns were more frequent at lower target-to-masker ratios (TMRs) and were oriented toward the target speech source. When the masker was competing speech the ultimate head orientation angle was larger at lower TMRs. These observed head movements are not consistent with a strategy that maximizes either the target level at a single ear or binaural unmasking of speech.