Examples of the counting of the number of pulses in 10 s of recording containing individual sounds (a) and chorus (b). Each bar indicates one pulse. Sampling frequency 44.1 kHz, 1024 point FFT, Hamming window.
Comparison between the spectrum of the field recorded boat noises and S. umbra sounds (S) and chorus (C) with the S. umbra audiogram (Codarin et al., 2009). CC: 8.5-m cabin-cruiser with 163-hp inboard diesel engine moving at 6 kn; FB: 5-m fiberglass boat with 40-hp outboard engine moving at 15 kn; INF: 7-m inflatable boat with 130-hp inboard–outboard engine moving at 20 kn.
Sciaena umbra pulse rate (mean ± S.E.M.) recorded 5 min before (dark gray) and after (light gray) each boat passage in the BOAT condition.
Sciaena umbra pulse rate (mean ± S.E.M.) recorded following six successive boat passages in the BOAT condition (dark gray) and in the CONTROL condition (light gray).
No significant change in background noise that included the S. umbra chorus was observed between the BOAT condition (dark gray) and the CONTROL condition (light gray) based on L eq,1 min (equivalent continuous SPL) calculated over the (a) 80 to 2500 Hz frequency band or over the wider (b) 2 to 20 000 Hz frequency band.
Article metrics loading...
Full text loading...