Ambient Noise Analysis in Shallow Water of Arabian Sea Based on Ocean Depth

Ambient noise is the typical and persistent unwanted background of sound at a particular location in the ocean at a given time of a year. This may be due to a variety of natural and artificial sources including seismic activity, oceanic turbulence, wind, distant shipping and marine organisms [Etter, 1991, Chapter 6]. It is location and time specific. In this paper, variation of ambient noise with depth was studied. Datas were collected at shallow water of Arabian sea using sensitive hydrophones at various depth and time. Data were collected for the period of six months to a wind speed ranges between 0.5 m/s to 7 m/s and the analysis were performed for frequencies ranging from 500 Hz to 7 KHz. Here we considered wind as the noise source. Frequency versus noise spectral density graph was plotted for various ocean depth. Linear relationship between the sea noise spectrum levels and the wind speed were found for the entire frequency range. Then the graph was plotted for various depth. It is concluded that in shallow water there is no much more variation in the ambient noise with depth and time.