Flashcards in Lecture 7 Deck (70)
How do whales communicate?
very specific song patterns
If blue whales are found in pairs they may be several...?
Does sound travel faster in water or air?
Sound travels up to 5 times faster in water than in air.
What is the breadth of blue whale calls?
Whales can produce calls as low as 14 Hz and as loud as 180 dB
Due to noise pollution what has happened to the hearing ability of blue whales?
they can only hear 100 miles away as oppose to 1000 miles away in 1940
Male songs have dropped in pitch by 30% since 1960s.
Right whales now communication at frequencies ______________ higher than they did a century ago.
2/3 of an octave
What do blue whales do when they find food?
tend to emit mid-frequency calls and communicate with conspecifics in the area
What study did Goldbogen conduct?
Performed a series of studies on the disruptive effect of mid-frequency sonar on blue whales
what sound does military sonar emit?
emits sounds between 1-10 KHz
What has military sonar frequencies been linked to?
mass strandings and large scale mortality, especially in beaked whales
The mid frequencies are ________ than the most sensitive auditory perceptive range in most toothed whales.
the mid frequencies are _______ that the long distance calling frequencies.
What kind of effect did military sonar have on whales that surface fed?
they showed little to no change in behavior pattern
What kind of effect did military sonar have on whales that deep dive fed?
suddenly terminated feeding
switched to mid water dive
increased swimming speed
swan away from sonar emission
what gender produces loud songs and why?
only male blue whales sing loud songs to find mates
Two types of hearing:
how do particle detectors work?
long thin organs that move when barraged by many particles
--only work in near field
Give an example of an animal with a particle detector
--courtship dance of male flies that females can detect and monitor near filed signals with an arista
What is an example of particle detector in male mosquitos?
Plumose antennae are used to detect the species specific wing beat of females.
What's an example of a particle detector in roaches and crickets?
Very fine hairs at the tips of their abdomens
• Variations in the lengths of these hairs is correlated with the particular near field sound frequencies to which each hair is sensitive
how do particle detectors provide mechanical advantage to an animal?
long hairs and antennae that attach to the cuticle of the animal.
--small force distributed over the axis of hair is sent to sensory cells as small displacement but one of great force.
What are some other advantages of particle detectors
very weak sound field can be detected by these types of receivers
mosquito antenna are one of the most sensitive auditory receptors among anthropods.
What are some cons of particle detectors?
signal amplitude and direction are confounded
dipolar near fields dont produce particle movements whose axis points at the source
What are the characteristics of particle detectors?
• lower frequencies
• Dynamic ranges and temporal tracking ...
• slowly varying waveforms well
• Provide relatively undistorted signals to sensory cells • Inherently directional
• Use is limited to near fields
describe a pressure detector?
Tympanum couples sound to the medium, relies on pressure differences on each side of membrane.
What happens if there's unequal pressure?
the membrane is bent away from the side of higher pressure. This bending can be coupled to sensor cells to produce neural impulses
Pressure detectors consists of...?
consists of a tympanum stretched over a closed cavity
how do pressure detectors work?
• As air pressure changes on one side of the tympanum it will bulge and bend to accommodate these changes causing vibrations along the membrane
• These vibrations can then be coded and transmitted to sensory cells
What is the equation for pressure detectors?
The force (F) on a tympanum is equal to the product of sound pressure (P) and membrane area (A); F=PA
large thing membranes are...?
very efficient ways to trap incident sound energy
the thinness of the membrane and restorative factors..?
created by compression of a closed cavity volume also help to track changes in incident waveforms rapidly
Tympana can be thin so their...?
so their acoustic impedance is close to that of air
Most of the sound energy carried in air will be...?
reflected at the ears
Terrestrial organisms consist of...?
water and solids
Pressure detectors lack...?
Intrinsic ability to detect direction
what is the sound shadow effect?
region of reduced amplitude of a sound because it is obstructed by the head.
what is the interaural intensity difference?
sound coming from a source located to one side of the head will have a higher intensity, or be louder, at the ear nearest the sound source
what is the interaural time difference
difference in arrival time of a sound between two ears. It is important in the localization of sounds, as it provides a cue to the direction or angle of the sound source from the head.
what is the max detectable delay for pressure detectors on humans?
for animals with only 1 cm seperating its ears what is the detectable delay?
describe the cochlea
Fluid filled structure that contains Basilar Membrane and the Organ of Corti
describe place theory
theory of hearing which states that our perception of sound depends on where each component frequency produces vibrations along the basilar membrane.
what is volley principle
groups of neurons of the auditory system respond to a sound by firing action potentials slightly out of phase with one another so that when combined, a greater frequency of sound can be encoded and sent to the brain to be analyzed.
describe anuran calls
simple and stereotypes, used to attract mates and warn off competitiors
the anuran air sac helps with what?
what happens if you puncture anuran air sac?
results in a decrease in sound pressure level by a factor of 5.
How is anuran larynx similar to that of a reptile?
Cricotracheal cartilage attached to the arytenoid cartilages
• Lacks thyroid cartilage
Are anuran male larynx bigger than that of females?
male larynx is heavier and larger than females though females are larger than males
in anuran calls, vocal cords are responsible for what?
tonal quality of the signal generated.
what is the primary center for the production of advertisement calls.
Males show significantly __________ neuronal response in this area than females.
How are these anuran calls conducted?
Males cluster within an area and wait for females to arrive
• While waiting, some males call while others remain silent
• Depending on the density of males in the area, there can be a lot of calling competition
Because males need to detect relatively noise free opportunities to call, they need to asses background noise in 3 domains:
signal bandwidth (frequency)
Because females need to identify and locate preferred males in a noisy environment, they need to asses calls how?
Localize potentially relevant signals
discriminate between conspecifics and heterospecifics
use calls to find males of high genetic quality
Describe the ear mechanisms of anurans.
don't have external ears
--two middle ear symptoms with a tympanum, middle ear cavity and stapes.
--connected directly with the oral cavity
What is the opercularis system?
specialized for highly directional soundlocalization
• Auditory signals make contact with the ear drum from both sides
Anuran inner ears consists of 2 spatially separated organs:
basilar papilla, intraspecific differences based on sex and size.
in coqui frogs, males produce a two note ad call:
co: male-male competition, lower frequency
qui: attract mates, produced 100msec later, higher frequency
t/f: the excitatory frequencies of the amphibian papilla are the same for males and females
in coqui frogs, males have a greater number of what?
cells in the basilar papilla tuned to the “CO” note than do females
in coqui frogs, females have a larger number of what?
cells within the basilar papilla that are tuned to the “QUI” note
t/f:Best excitatory frequency of the basilar papilla is tuned to a lower frequency in males than in females
false, tuned to a higher frequency
Anurans are _________ so temp affects their behavior directly
Changes in temperature effect best excitatory frequencies in the ________ papilla but not for the _________ papilla
in coqui frogs, the auditory nerve...?
is capable of temporal integration varying as a function of frequency
What are the frequency ranges of coqui frogs and the length of the integration times?
Frequencies below 500 Hz had the longest integration times
• Frequencies between 500-1200 Hz have the shortest integration times
• Frequencies above 1200 Hz have intermediate integration times
What are some characteristics of the coqui frog?
Differences in integration times allows for brief periods of silence between the “CO” and “QUI” notes
• Males minimize acoustic jamming
• Females receive an opportunity to more readily evaluate the signals of individual males
coqui frogs possess a _________ _______ _____ surrounding lung cavity
sound receiving mechanism,
The sound receiving mechanism in coqui frogs are most sensitive to...?
signals in the 1300-2600Hz range