The sense of a human being is expressed in a word always with the sensuous evaluation to idling noise. However, due to the sense of the human being is very complicated basically and be including delicate elements, there is a limit to express it in a word. Also, idling noise might be giving a stress to our body, without feeling it. Then, several studies have been made on physiological information receive the response of a human being objectively, tried to evaluate the load of a body.Electrocardiogram (ECG) and respiratory curve were measured to examine the influence that the disclosure of idling noise exerts on the autonomic nervous system function in this study. Heart rate variability (HRV) was obtained from ECG and respiratory frequency was obtained from respiratory curve in the analysis. Seven subjects were adult males who were healthy hearing.We investigated the result with considering the differences by 4 kinds of noise and 2 kinds of sound pressure. Respiratory sinus arrhythmia (RSA) frequency was directly proportional to respiratory frequency and RSA peak value was inversely proportional to respiratory frequency, without being related to the presence of the respiratory control. We proposed R&H Method as the analysis method of HRV, from that respiratory frequency is appearing in power spectrum of HRV as RSA. These results suggested that R&H Method which considered the physiological reaction characteristic of each subject was suited as the analysis method of HRV. Consequently it is conjectured that R&H Method could estimate the degree of the mental stress was caused by the disclosure of idling noise.