Figure 6.

Subspaces in which selected materials are most separated. Two-dimensional subspaces computed by LDA with four acoustic features. Examples for 3 participants are shown (a) participant #1; (b) #2; (c) #3). For participant #1, plots in the constant room condition (left) and varying room condition (right) are shown. For participants #2 and #3, plots in the constant room condition are shown but those in the varying room condition are omitted. Each dot represents one sound. Colours and shapes indicate materials (green circles: wood, orange triangles: metal, purple crosses: glass). Selected materials appeared well separated by the linear combination of the acoustic features in both contexts.