Focusing on the assessment of environmental noise pollution in urban areas, we provide qualitative considerations and experimental results to show the feasibility of wireless sensor networks to be used in this context. To select the most suitable data collection protocol for the specific noise monitoring application scenario, we evaluated the energy consumption performances of the CTP (Collection Tree Protocol) and DMAC protocols. Our results show that CTP, if used enabling the LPL (Low Power Listening) option, provides the better performances trade-off for noise monitoring applications.