What keeps you awake at night? Money worries? Your conscience? Traffic? Dogs barking? Or the shrill sound of a stressed robin forced to sing at night to find a mate?

This composed feature by Nina Perry explores the problem of sleeplessness and the crucial relationship between sound and sleep, all set within a soundscape of noises heard during a sleepless night interwoven with specially composed music.

Tinnitus sufferer Helen takes us on a journey through a sleepless night of thought and sounds of ticking clocks, snoring, a restless child, mysterious footsteps and a neighbour's late night party. How are these sounds perceived in a state of sleeplessness? How do we respond to sound emotionally, physiologically and hormonally. Are the sounds of the night changing? Are silent nights a thing of the past?

Answering these questions and elucidating the relationship between sound and sleep are: Professor of Acoustics and Dynamics Andy Moorhouse and Senior Lecturer in Acoustics Bill Davies, from Salford University; David Baguley, Head of Audiology at Cambridge University Hospitals, who discusses sound perception, the meaning of sound and the reaction to sound as elements within Tinnitus treatment; Dr Ken Hume, a sleep researcher specializing in sound and sleep, discussing the physiology and psychology of sleep and sound disturbance; and Rupert Marshall, Lecturer in Animal Behaviour at Aberystwyth University, describing how urban wildlife is changing its behaviour to cope with modern life (for example, robins nesting in urban areas who struggle to be heard during the day are more likely to sing at night than their country cousins).

Producer: Nina Perry

A White Pebble Media production for BBC Radio 4.