Understanding our perception of rhythm

Scientists have long known that while listening to a sequence of sounds, people often perceive a rhythm, even when the sounds are identical and equally spaced. One regularity that was discovered over 100 years ago is the Iambic-Trochaic Law : when every other sound is loud, we tend to hear groups of two sounds with an initial beat. When every other sound is long, we hear groups of two sounds with a final beat. But why does our rhythm perception work this way? In a recent study in Psychological Review , McGill University Professor Michael Wagner shows that the rhythm we perceive is a result of the way listeners make two separate types of decisions, one about grouping (which syllables or tones group together) and the other about prominence (which syllables or tones seem foregrounded or backgrounded). These decisions about grouping and prominence mutually inform each other. The findings may deepen our understanding of speech and language processing, with potential implications in a wide range of areas, including teaching, speech therapy, improving synthesized speech, and improving speech recognition systems. What do scientists know about our perception of rhythm? Sequences of tones and syllables are often perceived as rhythmically grouped.