The crackle of white noise greeted me as I switched it on. I noticed a distant pulsing signal that drew me towards it. I was in the front room of my flat and its intensity increased as I started to approach my settee. The sound throbbed with metallic bass tones. I moved my receiver towards the settee then back again. The signal was surprisingly spatial. I carefully traced its shape revealing a giant invisible pulsating electromagnetic sphear hovering above my orange settee.