Similarly, in some lower forms, the visual appearance of a letter might generate color, whereas in higher forms it is the sound, or phoneme, summoned by that letter; phonemes are represented near the TPO.

• 同样地，某些较低等的型式，可能是由字母的视觉外形引发颜色感，但在较高等的型式，则可能是由字母所引发的声音（音素）引起；音素的呈现区是在靠近TPO的位置。