This study examined the relationship between noise annoyance and sound pressure levels in indoor environments due to various modes of transportation including road traffic, railways, and aircraft. The experiments were conducted in a laboratory environment, where the limited sense of presence was overcome by using an appropriate exposure duration. The degree of annoyance was surveyed and the average score was converted into percent of annoyance (%PA) and percent high annoyance (%HA) values among respondents for comparisons with the noise levels. As expected, the subjective response increased in proportion with the noise level and there was an extremely high correlation. Notably, the smallest deviation in responses was found for road traffic noise. Overall, the noise levels corresponding to a %PA of 50% were 41 dB(A), 48 dB(A), and 49 dB(A) for road traffic noise, railway noise, and aircraft noise, respectively. In addition, the levels corresponding to a %HA of 20% were 45 dB(A), 51 dB(A), and 53 dB(A), respectively. The %HA values coincided well with current regulations for indoor noise in Korea (45 dB(A)).