The work explores the phenomenon of echo location in bats. The image in glass of the inverted bell is used to evoke a bat’s aural landscape of resonance and sound reflexion. The circle of the outer form reproduces the design of the circular leaded windows in the North gallery and staircase. The glass panes are replaced with sheets of darkened wood to pick up on the traditional church furniture and other wooden objects. The radiating lead lines suggest the ultrasounds that a bat emits with its call to locate flying insects and build up a kind of sonic map of its environment. The transparency of bat and moth wings is examined through various surface treatments.