Abstract
Summary
For some time it has been known that “complex” sound stimuli are more effective than pure tones in eliciting behavioural and other responses from infants aged 0-6 months. We have recently studied this issue in some detail, and confirm that stimulus complexity defined in terms of frequency bandwidth is of major importance in eliciting behavioural responses from infants aged 1 week, 6 weeks and 6 months. We have also found that the human voice is effective for 6 month oldinfants but apparently not for babies aged 1 and 6 weeks. These findings are modified by the baby's state of wakefulness, the effects of which are also considered. Comments are made on the implications of our data for clinical audiological assessments.