Littoral Transmissions meander through the sonic landscape of the River Lea from Stonebridge Lock to Leamouth. Recordings from the field converge with layers of sound to create an aural impression of the navigation.

In this episode: pausing for breath at the tunnel's mouth, on the threshold of a threshold. Resonances haunt endlessly, back and forth, echoing around the next bend.

Resonance Extra - 24/7 sound art, radio art and global music. Listen on DAB+ in Brighton, Bristol, Cambridge, London and Norwich or via http://extra.resonance.fm