Environmental noise is a very important factor determining the residential quality. There are many environmental noises produced in residential area, and transportation noise is one of the most annoying among those noises. Measurement and evaluation method are specified in standard for the single transportation noise, while method for the mixed noise is not specified. To evaluate mixed transportation noise, the analyzing the relationship between sound sources is necessary. Many researches have been carried out to seek for the relationship, and equations were proposed based on the research which was usually carried out in the specific condition. Field survey is generally used to analyze the relationship between sound sources and also to make regulations by analyzing how many people are annoyed for specific noise level. However it is really difficult to control variables and it needs a lot of time and money to survey. For this reason, laboratory test is used to analyze, because it could be somewhat free from such variables that have in field survey. Nevertheless laboratory test is could be different with real situation. Most of all noise exposure time is considered to be different with real situation, and this study aimed to compare the subjective response for the different length of sound sources. As a result, the annoyance for the road traffic noise was increased proportional to exposure time, however it was decreased suddenly for the railway noise and aircraft noise after 20 sec. because of the background noise, then increased with relatively slow slope. Especially the slope of annoyance in the relationship with equivalent noise level differed depending on the exposure time.