Ambisonic Strata

Ambisonic Strata is software I am developing to see Ambisonic sound fields. An Ambisonic recording or composition holds sound from every direction around the listener, above and below included. Strata analyses the whole file and turns it into a single form in four dimensions: the sphere of directions around us, and time.

Every sound becomes a particle, placed in the direction it is heard from and traced through time. Its spectrum shows as colour, from red for low frequencies to violet for high ones, so broadband sound mixes towards white; its diffuseness shows as size, and its loudness as opacity. Enveloping, diffuse sound is drawn as a fine haze. A whole piece can be seen at once as one form, or followed as it unfolds, with binaural playback on headphones that stays in step with the picture.

I started it to help people study spatial sound without constant access to a multi-loudspeaker Ambisonic studio. I also wanted to give artists in the field or on tour a way to check and analyse their compositions and recordings, and to offer anyone who simply wants it a spectacular visual experience alongside their Ambisonic works.

Most Ambisonic visualisers draw the sound field as it is at this moment: a map of energy around the listener, replaced by the next one. Strata keeps every moment, so the spatial dynamics, structure and form of a piece can be read the way layers of particles are read, as a record laid down over time. At a glance, you can see how composers unfold spatial gestures and textures, and how recordings reveal the spatial magic of a place.

Four views of the same analysis. Strata: Drifting Voices whole, time as radius from 0:00 at the core. Nebula: FOMO playing, the next five seconds inside the ball. Column: Drifting Voices, time rising; sounds circling the listener become rings. Space–time cube: FOMO, the sphere unfolded like a map.

I am still finding out what each view reveals, and I will keep sharing as it grows.