Animals share acoustic space to communicate vocally. The employment of passive acoustic monitoring to establish a better understanding of acoustic communities has emerged as an important tool in assessing overall diversity and habitat integrity as well as informing species conservation strategies. This chapter aims to review how traditional and more emerging bioacoustic techniques can address conservation issues. Acoustic data can be used to estimate species occupancy, population abundance, and animal density. More broadly, biodiversity can be assessed via acoustic diversity indices, using the number of acoustically conspicuous species. Finally, changes to the local soundscape provide an early warning of habitat disturbance, including habitat loss and fragmentation. Like other emerging technologies, passive acoustic monitoring (PAM) benefits from an interdisciplinary collaboration between biologists, engineers, and bioinformaticians to develop detection algorithms for specific species that reduce time-consuming manual data mining. The chapter also describes different methods to process, visualize, and analyse acoustic data, from open source to commercial software. The technological advances in bioacoustics turning heavy, non-portable, and expensive hardware and labour and time-intensive methods for analysis into new small, movable, affordable, and automated systems, make acoustic sensors increasingly popular among conservation biologists for all taxa.