Eight bottlenose dolphins Tursiops truncatus (four male, four female) were trained to respond to 100-ms tones. Three male dolphins (ages 23, 26, and 34) exhibited hearing disability at four higher frequencies-70, 80, 100, and 120 kHz even at 111-135 dB re: 1 microPa. Two females (ages 32 and 35) responded to all frequencies as did a male (age 7) and a female (age 11). One female (age 33) respon...

Despite well-documented experimental evidence of echolocation in toothed whales, virtually nothing is known about the use and functional significance of cetacean sonar in the wild. Here, the patterns of echolocation sounds produced by killer whales, Orcinus orca, off British Columbia and Alaska are described. Two sympatric populations with divergent food habits differed markedly in sonar sound ...

The spectral and temporal properties of echolocation clicks and the use of clicks for species classification are investigated for five species of free-ranging dolphins found offshore of southern California: short-beaked common (Delphinus delphis), long-beaked common (D. capensis), Risso's (Grampus griseus), Pacific white-sided (Lagenorhynchus obliquidens), and bottlenose (Tursiops truncatus) do...

An intrusion detection systems (IDS) detect and prevent network attacks. Due to the complicated environment, ID system merges a high number of samples into small normal samples, resulting in inadequate identify train maximum false rate. External malicious attacks damage conventional IDS, which affects activity. Adaptive Dolphin Atom Search Optimization overcomes this. Thus, work aims create an ...

Understanding the spatial and temporal structure of ambient noise is a critical factor for estimating the performance of active and passive sonar systems. This is especially true in warm shallow waters where snapping shrimp dominate the ambient noise spectrum over 6 octaves. Snapping shrimp sources can be problematic for active sonar, but are key sources for Ambient Noise Imaging systems. The i...

Dynamic response of a structure is a remarkable characteristic which can be optimized (controlled) by imposing constraints on natural frequencies. But it is mentionable that size and shape optimization of trusses with multiple frequency constraints is a very non-linear and non-convex problem that may be converged to local optima when using meta-heuristic algorithms. To concur this problem, rese...

Toothed whales (Cetacea, odontoceti) use biosonar to navigate their environment and to find and catch prey. All studied toothed whale species have evolved highly directional, high-amplitude ultrasonic clicks suited for long-range echolocation of prey in open water. Little is known about the biosonar signals of toothed whale species inhabiting freshwater habitats such as endangered river dolphin...

Geographe Bay, south-western Australia has been host to several past mass live cetacean (whale and dolphin) strandings. It is noticed that the majority of stranded whales tend to be healthy, toothed cetaceans (Odontoceti) which employ echolocation as a method of navigation. This paper explores a bioacoustic mechanism known as sonar termination as a major factor in the occurrence of these strand...