Glossary - P
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P

Pacific humpback dolphin
also known as the Indo-Pacific humpback dolphin; Sousa chinensis
Pacific Missile Range Facility (PMRF)
a U.S. Naval facility off the island of Kauai, Hawaii, that is the world's largest instrumented, multi-dimensional testing and training missile range. It is the only range in the world where submarines, surface ships, aircraft, and space vehicles can operate and be tracked simultaneously. There are over 1,100 square miles of instrumented underwater range and over 42,000 square miles of controlled airspace. Additional bottom-mounted hydrophones are being installed at PMRF in early 2011, and similar to AUTEC and SCORE, a Marine Mammal Monitoring (M3R) system is being installed to monitor vocalizing animals.
Pacific white-sided dolphin
Lagenorhynchus obliquidens
pack ice
a large expanse of floating ice
pan bone
thin bone in the back of the lower jaw that helps transmit sound to the middle ear
parallel
being an equal distance apart everywhere, extending in the same direction, never meeting or intersecting
particle motion
the change in position of a particle with respect to time; in acoustics, particle motion is vibratory motion in which the particles move back and forth around an equilibrium point.
passive acoustics
listening to sound sources; sound is only received
peak pressure
the range in pressure between zero and the greatest pressure of the signal.
peak pressure/0-to-peak pressure
the range in pressure between zero and the greatest pressure of the signal
peak-to-peak pressure
the range in pressure between the most negative and the most positive pressure of the signal
pectoral fins
the uppermost of the paired fins on a fish
pectoral flipper
forelimbs of whales and dolphins that are used for stability and steering. These appendanges are generally flattened and paddle-like. Humpback whales have very large pectoral flippers, reaching 5 m (15 ft) in length.
pectoral free rays
rays that are part of the fishes pectoral fins but are free from the actual fin skin. These rays aid in the movement of the fish.
pectoral girdle
the bony or cartilaginous arch that supports the forelimbs of a vertebrate
peer reviewed
scientific papers that have been subjected to evaluation by highly qualified experts in the field, the reviewers are usually anonymous and check the papers for inconsistencies, invalid conclusions and editorial errors
peer-reviewed
a process by which a scholarly work (such as a paper or a research proposal) is checked by a group of experts in the same field to make sure it meets the necessary standards before it is published or accepted
pelagic
of, relating to, or living or occurring in the open ocean.
pelagic species
organisms that swim or drift in the water; these organisms are distinct from those living on or in the bottom sediments.
perceive
to recognize, discern, or understand.
permanent threshold shift (PTS)
a permanent increase in the threshold of hearing (minimum intensity needed to hear a sound) at a specific frequency above a previously established reference level
perpendicular
being at right angles
pharyngeal
teeth located in the gill or throat region
phocids or true seals
seals, such as harbor seals, that have no visible ear flap. They have a streamlined body with short front flippers. Their hind flippers are directed backward and they are not used for walking on land.
phon
a unit of loudness for pure tones that accounts for the perceived loudness of tones; the number of phon of a sound is the decibel of a sound at 1 kHz that is perceived to be just as loud.
photophores
light producing organs that appear as bright spots on various marine animals, including fishes and cephalopods.
physiological stress
a reaction to a change that requires a physical, mental or emotional adjustment or response.
piezoelectric effect
the ability of some materials (notably crystals and certain ceramics) to generate electricity in response to applied mechanical stress
piezoelectric material
a material that produces electrical charges when subjected to pressure changes
pilot whale
Globicephala spp.
ping
to query (another computer on a network, or in this case, an acoustic transponder) to determine the location of it.
pink snapper
Pagrus auratus
pink snappers
Pagrus auratus
pinna, auricle
the ear flap or outer part of the ear that extends from the head. The pinna funnels sound down the outer ear canal to the eardrum.
pinniped
group of mammals that includes seals, sea lions and walruses
pitch
an up-or-down movement of the front (bow) of a vessel (ship, glider, etc.).
plainfin midshipman
Porichthys notatus
plane wave
a wave in which the wave fronts are a series of parallel planes.
plankton
relatively small organisms that drift or float passively in the water and are carried wherever currents and tides take them. Plankton are often microscopic and are an important food source for other aquatic organisms. There are two types of plankton- phytoplankton (plants and autotrophs) and zooplankton (animals).
plectrum
part of the spiny lobster that is found underneath the files. It is a soft piece of tissue that is found at the base of the antennae. The plecta is what the lobster pulls over the files to produce sound
pneumatic
containing or operated by air or gas under pressure.
pod
a social group of whales that are clustered together. Some toothed whales, such as orcas travel in large, sometimes stable pods. They may group together to hunt their prey and/or migrate.
polar bear
Ursus maritimus
polar bear
Ursus maritimus
pollack
Pollachius pollachius
polyps
small marine invertebrates that have hard, cup-like, limestone skeletons. Polyps live in large colonies where they take-in the calcium from the ocean and to build a hard shell around themselves. The skeletons grow one on top of one another and as a result a coral reef is able to grow.
population
the entire collection of individuals or items from which samples are drawn.
power
the probability of rejecting the null hypothesis in a statistical test when it is false.
precision
the degree to which repeated measurements under unchanged conditions show the same results; reproducibility; repeatability.
prehensile
adapted for seizing, grasping, or holding, especially by wrapping around an object.
pressure
the amount of force per unit area measured in units of atmospheres (atm)
profile
the change of an oceanographic variable with water depth
projector
an instrument that sends out sound waves; consists of a transmitter and a transducer
projector arrays
a collection of individual projectors used together to generate a directional sound beam
propagation
the movement of sound through a medium.
pulse
a short duration broadband signal.
pure tone
a sound that consists of one single frequency