DEVELOPMENT OF THE AUTONOMOUS UNDERWATER NOISE RECORDER

Abstract

An underwater noise is the most pervasive type of physical energy that spreads in underwater marine environment. The concerns regarding man-made underwater noise effects on the aquatic animals became prominent within scientific communities. The determination of underwater noise levels became very actual either for environmental monitoring or scientific research purposes. Various tools for acquisition of the underwater sound as well, modelling became available, although some techniques are costly and requires special considerations. One of the examples are the sound recording devices containing hydrophones along with digital sound acquisition systems used for recording of ambient (continuous) underwater sounds. By the date there are already developed the international and European standards for monitoring the long term (yearly) underwater continuous noise levels. However, the techniques known to be able to record the short and mid-term noise levels can serve for the research purposes greatly. In this research the cost efficient autonomous underwater sound recorder was developed, with the purpose to record an ambient underwater noise continuously and autonomously for the periods of up to 15 days, following the already known methods. In this paper we present the steps of the development of the autonomous recorder, its features and capabilities as well, calibration results of the underwater sound recording system.