*4.2. Identification Tests*

In experiment 1, experiment participants performed color identification on random sound samples that only transformed the color variable. As shown in Table 8, the color identification rate of Group A using six-color wheel codes was 100%. Additionally, for Group B with eight-color wheel codes used, the color identification rate was 86.67%.


**Table 8.** Six-color wheel and eight-color wheel code identification test in experiment 1 (color).

> In experiment 2, experiment participants performed color and lightness identification on random sound samples that transformed the color variable and the lightness variable. As shown in Table 9, the color discrimination rate and brightness discrimination rate of both groups A and B were 100%.

**Table 9.** total color codes identification test in experiment 2 (color + lightness).


In experiment 3, participants performed color, brightness, and depth identification on random sound samples representing color, brightness, and depth variables. As shown in Table 10, there is confusion between red and blue in a multivariate situation. It is possible that the sound on the right side of the HRTF sample is a bit louder than the sound on the left side, which makes the right side similar to the front sound in the case of reverberation. Additionally, in the multivariate case, the depth variable may show a small recognition error.

When we analyzed the identification test results shown in Table 11, we found that the identification rate of S3 participants was significantly lower than that of other participants. This may be due to the headset brought by the individual participant. Excluding the S3 participants, the discrimination rate results were much better.


**Table 10.** Total color codes identification test in experiment 3 (color + lightness + depth).

**Table 11.** Identification test results for each participant.

