An environmental noise study in the city of Ca´ceres, Spain J.M. Barrigo´n Morillas a, *, V. Go´ mez Escobar a , J.A. Me´ndez Sierra a , R. Vı ´ lchez Go´ mez a , J. Trujillo Carmona b a Departamento de Fı´sica, E. Polite ´cnica, Universidad de Extremadura, Avda. de la Universidad s/n, 10071 Ca ´ceres, Spain b Departamento de Matema ´ticas. F. Ciencias. Universidad de Extremadura, Avda. de Elvas s/n. 06071 Badajoz, Spain Received 4 October 2001; received in revised form 20 April 2002; accepted 3 May 2002 Abstract An urban noise survey was conducted in the city of Ca´ceres (Extremadura, Spain). In order to select the different points where measurements were to be taken, the streets were classified according to their use in communicating the different zones of the city. The four categories considered were all through roads (service roads were excluded): arterial roads outside the central zone, arterial roads in the central zone, other two-way roads connecting different zones, other one-way roads. The first two categories were found to be statistically indis- tinguishable, and together with the third had the highest noise levels—median Leq above 70 dB(A). The one-way roads were some 5 dB(A) quieter. Thus the sound levels in Ca´ceres, a small city, are quite high, with 90% of our measurements surpassing an Leq of 65 dB(A) during working hours. Finally, relationships were established between the equivalent level, traffic flux, and the main noise level percentiles, with results in good agreement with those of other authors. We can also conclude that city noise can be usefully studied by classifying the streets according to their use. # 2002 Elsevier Science Ltd. All rights reserved. Applied Acoustics 63 (2002) 1061–1070 www.elsevier.com/locate/apacoust 0003-682X/02/$ - see front matter # 2002 Elsevier Science Ltd. All rights reserved. PII: S0003-682X(02)00030-0 * Corresponding author. Tel.: +34-927-257234; fax: +34-927-257203. E-mail address: barrigon@unex.es (J.M. Barrigo´n Morillas).