What is Audio Recording?

Audio recordings have had many uses across ecology and conservation fields of research, both on land and within the ocean. Audio recorders can include one or more microphones, a way to store or transmit the recording, and an energy source (Küsel et al, 2016). These can either be operated by an individual manually pointing a microphone at the intended sound source, or can be set up and left to continuously record or record on intervals for stretches of time usually with multiple directions being recorded. Of course audio recorders can be used to record the calls or vocalizations of individuals to study a species, but they are also key to a new field Pijanowski et al (2011) calls “soundscape ecology” which can be used in “monitoring the health of remote habitats and documenting fish spawning activities” (Lindseth & Lobel, 2018). Passive Acoustic Monitoring (PAM) is a common and well supported method in recording marine mammals via gliders and buoys (André, 2014; Küsel et al, 2016), while PAM has been used for the last three decades on land primarily studying bats and birds (Sugai et al, 2019; Zhao, 2019). PAM is set by an individual and then left for the study period to record sounds without human presence. Once a recording is collected, scientists can look at a visual graph of the sound called a spectrogram. Audio recordings can provide scientists with data over time on species richness, biodiversity, presence of humans, and overall health of habitats (Blumstein, 2011).

Photograph by Rob McClelland (2019), Swapping Sensors, Channel Islands, CA