The investigation comprised "eld measurements of road tra$c noise at over 60 sites in 8 cities in South-Eastern Nigeria and psychological survey, by questionnaires, of respondents living and working close to the sites. Instantaneous and 24 h noise measurements were made at the noisiest points, near the facades, of the houses of more than 150 respondents in the neighbourhood of each site. Several noise descriptors were either measured or calculated. Measured values of ยธK?V were as high as 105 dB (A) while residents were exposed to instantaneous levels of road tra$c noise as high as 110 dB (A). Values of ยธCO and ยธBL were 84)6 and 68)0 dB (A), respectively, and sometimes higher in some of the sites. The calculated ยธ correlated positively with "eld data with a correlation coe$cient of 0)8551. It was found that the measured ยธ was always higher than the calculated ยธ by about 4)5}8)8 dB (A) probably because of the reckless use of horn by motorists and re#ection from the hills and trees. The type of house lived in, the disturbance of various activities by road tra$c noise and neighbourhood noises which were most annoying to residents, were found to strongly a!ect the percentage of responses obtained with respective correlation coe$cients of 0)9925, 0)9714 and 0)7237. The usual poor correlation, ranging from 0)3 to 0)4, between dissatisfaction response and noise exposure were obtained in this investigation. There appeared to be an income bias with respect to community response to road tra$c noise, with low-income neighbourhoods reporting less annoyance and disruption of various activities by road tra$c noise, and some evidence of adaptation to road tra$c noise by residents of busy cities in South-Eastern Nigeria.