Figur 4. Spektrogram (hovedpanel), effektspektral tetthet (PSD, høyre panel) og bølgeform (nedre panel) av akustiske forhold i Ovum før (0-24 s), under (24 s) og etter (25-60 s) at en undervannsluke ble stengt med et smell. Hydrofonen var plassert 6 m unna luken. Lydtrykksnivået (SPLRMS) var 132 dB re 1 µPa over 20-1000 Hz, med et 60-s lydeksponeringsnivå (SEL) på 150 dB re 1 µPa2s. Spectrogram (main panel), power spectral density (PSD, right panel) and waveform (lower panel) of acoustic conditions before (0-24 s), under (24 s) and after (25-60 s) an underwater hatch was closed with a slam. The hydrophone was placed 6 m from the hatch. The sound pressure level (SPLRMS) was 132 dB re 1 µPa over 20-1000 Hz for 60 s, with a 60-s sound exposure level (SEL) of 150 dB re 1 µPa2s.
