C-weighting for high-amplitude sounds). In this method the signal is first weighted (filtered) relative to hearing abilities of species under test and the SEL or accumulated SEL is then calculated (Theobald et al. 2009). This has the advantage that for signals containing multiple frequency components, energy contributions from frequency components outside the hearing band of the species will be reduced or removed from the overall exposure estimate. Again this is analogous to human hearing accumulated exposure measurements. It should be noted that in this treatment by Southall et al. (2007), the injury criteria consider both SEL and SPL, where the SPL is considered for a peak level and is not subjected to a weighted response.
59. A series of frequency weighting functions have been developed based on current knowledge and interpolation of appropriate marine mammal hearing data and grouped into functional marine mammal hearing groups (see Table 9.1).
Table 9.1. Functional marine mammal hearing groups taken from Southall et al. (2007). Genera represented
Function hearing group/Frequency- weighting network
Low-frequency cetaceans – Mlf
Mid-frequency cetaceans – Mmf
Estimated auditory bandwidth
7 Hz to 22 kHz 150 Hz to 160 kHz
Balaena, Caperea, Eschrichtius, Megaptera, Balaenoptera (13 species / subspecies)
Steno, Sousa, Sotalia, Tursiops, Stenella, Delphinus, Lagenodelphis, Lagenorhynchus, Lissodelphis, Grampus, Peponocephala, Feresa, Pseudorca, Orcinus, Globicephala, Orcaella, Physeter, Delphinapterus, Monodon, Ziphius, Berardius, Tasmacetus, Hyperoodon, Mesoplodon (57 species / subspecies)
High-frequency cetaceans – Mhf
200 Hz to 180 kHz Pinnipeds in water – Mpw 75 Hz to 75 kHz
Phocoena, Neophocaena, Phocoenoides, Platanista, Inia, Kogia, Lipotes, Pontoporia, Cephalorhynchus (20 species / subspecies)
Arcocephalus, Callorhinus, Zalophus, Eumetopias, Neophoca, Phocartos, Otaria, Erignathus, Phoca, Pusa, Halichoerus, Histriophoca, Pagophilus, Cystophora, Monachus, Mirounga, Leptonychotes, Ommatophoca, Lobodon, Hydruga, and Odobenus (41 species / subspecies)
Pinnipeds in air – Mpa 60. 75 Hz to 30 kHz Same species as pinnipeds in water (above)
It is acknowledged by Southall et al. (2007) that these filters are much ‘flatter’ than audiograms and are probably quite precautionary even considering the expected
Preliminary Environmental Information May 2014
East Anglia THREE Offshore Windfarm Appendix 9.1 Underwater Noise Modelling 20
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103 |
Page 104 |
Page 105 |
Page 106 |
Page 107 |
Page 108 |
Page 109 |
Page 110 |
Page 111 |
Page 112 |
Page 113 |
Page 114 |
Page 115 |
Page 116 |
Page 117 |
Page 118 |
Page 119 |
Page 120 |
Page 121 |
Page 122 |
Page 123 |
Page 124 |
Page 125 |
Page 126 |
Page 127 |
Page 128 |
Page 129 |
Page 130 |
Page 131 |
Page 132 |
Page 133 |
Page 134 |
Page 135 |
Page 136 |
Page 137 |
Page 138 |
Page 139 |
Page 140 |
Page 141 |
Page 142 |
Page 143 |
Page 144 |
Page 145 |
Page 146 |
Page 147 |
Page 148 |
Page 149 |
Page 150