a b s t r a c tThe zoo visitor effect is the change in animal behaviour and physiology in response to the presence of a viewing public. It is thought to result from, amongst other things, visitor generated sound (i.e., noise), but this hypothesis has never been explicitly tested. We tested this hypothesis through observations on the behaviour and enclosure use of 12 mammal species held in 12 separate enclosures at the Belo Horizonte Zoo when exposed to different sound pressure levels (i.e., noise) from the visiting public. Noise pollution levels were significantly higher with the public present and increased with increasing audience size. Species that are more popular suffered greater noise pollution from the zoo visitors. No overall effects on behaviour were found in relation to noise levels, however, analysis of behaviour at the individual level found some significant differences. Notably, half of the individuals increased their vigilance behaviour with increasing sound levels and approximately onethird of individuals increased their movements. These results show that zoo visitors have a negative welfare impact on individual zoo-housed mammals, especially groups of noisy visitors where levels were recorded outside of the recommended limits for human wellbeing (>70 dB(A)). Thus, zoos need to address this issue, probably, through a combination of visitor education campaigns and acoustic modification to enclosures.

Urban areas and many natural habitats are being dominated by a new selection pressure: anthropogenic noise. The ongoing expansion of urban areas, roads and airports throughout the world makes the noise almost omnipresent. Urbanization and the increase of noise levels form a major threat to living conditions in and around cities. Insight into the behavioural strategies of urban survivors may explain the sensitivity of other species to urban selection pressures. Here, we show that urban black-tufted marmosets ( Callithrix penicillata ) living in noisy urban areas may select their home-range based primarily on ambient noise level. We have tested the hypothesis that the noise from vehicular traffic and visitors in an urban park in Brazil influences the use of home-range (space) by urban marmosets. Marmosets even avoided noisy areas with high food availability. In addition, they systematically preferred the quieter areas even with dynamic changes in the acoustic landscape of the park between weekdays and Sundays (no observations were made on Saturdays). These data provide evidence that the use of home-range by wild animals can be affected by a potential aversive stimulus such as noise pollution.

RESUMOEste estudo aborda a técnica de modelagem da resposta acústica de um veículo automotor. Esta pesquisa discorre sobre a construção de modelos numéricos em elementos finitos para investigar o efeito da utilização de componentes móveis (capô, portas laterais e tampa do porta malas) na resposta acústica de um veículo. Para tanto, foram construídos dois modelos: um que abrange a utilização de todos os componentes móveis, e outro, que substitui cada componente móvel por elementos unidimensionais (1D), contendo apenas a massa e a inércia que representa cada um destes componentes. A resposta obtida em cada uma das etapas da simulação numérica é comparada com os resultados experimentais, a fim de validar o procedimento e compreender a significância da utilização de um modelo numérico simplificado e assim, validar um modelo simplificado capaz de reproduzir computacionalmente e de forma satisfatória a resposta acústica de um veículo. A utilização do referido modelo simplificado possibilita a indústria automotiva realizar estudos sobre a performance acústica de um veículo de forma antecipada, uma vez que não necessita esperar o desenvolvimento destes componentes. Como investigado nesta pesquisa, a influência de componentes móveis sobre a resposta acústica do modelo numérico completo é pequena quando comparado à resposta obtida pelo modelo simplificado. Por meio de uma segunda