Fig. 1. Experimental setup for measuring the echoes of flowers (and other objects). Microphone (Brüel & Kjaer or GRAS 1/4'' condenser microphone) and loudspeaker (15 mm diameter) were as close to each other as possible, with their centers at a distance of 18 mm apart. The flower was fixed on top of a thin holder, which projected from a slender rod, at a distance of 20 cm from the loudspeaker-microphone array, and could be rotated by hand on a turntable.