"When sound is the programme, define the 'listening environment' before the equipment specifications"

From insect calls on outdoor ecology walks to sound art resonating among pipes inside an exhibition space, more programmes place sound itself at the centre of the content. Seoul Forest's night-time insect ecology programme and The Art of Sound at London's Wapping Hydraulic Power Station, part of London Design Festival, are representative examples.

The two events differ in location and format, but present on-site planners with the same fundamental challenge: first define "which sounds the audience must be able to distinguish", then work backwards to plan the space, time of day, group size and audio system around that objective. Once a sound programme starts by fixing an equipment hire list and taking it to the venue, it is headed for failure.

1. Outdoors: separate the 'commentary route' from the 'listening points'

A programme that listens to the natural outdoor environment, as in the Seoul Forest example, takes audiences directly into an ecological habitat. A common operational mistake is interference between commentary on the move and listening to the surroundings.

• Group size and distance limits: measure in advance the width of the moving group and the listening radius that one guide can manage.
• Rehearse separate sections: clearly distinguish and rehearse the 'moving section', where the guide speaks directly or through a wireless system, and the 'stationary listening section', where the audience listens to environmental sounds in silence. Pre-event checks must identify interference in which the guide's microphone level or wireless feedback masks the subtle insect calls the audience is meant to hear.
• Check the external noise timeline: outdoor programmes must check whether their times overlap with nearby stage rehearsals, generator operation or music from food and beverage (F&B) stalls.

2. Indoor playback: compare 'room reverberation' and 'file format' before positioning speakers

An exhibition that brings field recordings collected and edited elsewhere into an indoor space, such as London's former hydraulic power station, needs a different approach. Recordings spanning diverse frequency ranges—including birds' wingbeats, freight trains, friction at bridge joints and waves—must be conveyed without distortion inside the structure.

• Prioritise the space over equipment specifications: hiring and bringing in high-output speakers first can blur the intended audio detail because exposed concrete and steel structures have long reverberation. Review wall reflections, noise spilling in from adjacent areas and audio file formats, including lossless compression, before deciding speaker coverage angles and positions.
• Match audience routes to listening positions: even with free timed reservations, account for changes in sound absorption caused by crowding at particular times and for noise from audience movement.

3. A four-stage workflow for sound programmes

Planners and audio directors must work through the following four stages, from the kick-off meeting to the on-site acceptance test.

Five items for the acceptance record

Planner's note: change the Acceptance Criteria

On-site acceptance of a sound programme does not end when the speakers power up and someone presses play. Unloading and installation are complete only when the intended sounds have been verified as distinguishable from where the audience stands.

Before writing equipment model names into the plan or procurement specification, prepare a checklist stating the 'listening objective, expected noise sources, listening positions along audience routes, capacity and final acceptance conditions'. This is how planners can prevent wasted budgets and disrupted rehearsals.