Quantifying/Visualizing Sound

waveform

pressure/time

multiple frequencies

what do jagged lines mean in a waveform?

spectrogram

shows time, amplitude (brightness) and frequency (Y)

bandwidth

difference between start and ending frequencies

inter-call-interval

time between subsequent calls

frequency spectrum

frequencies summed over an entire time window (like a histogram)

harmonics

frequencies that are integer multiples of the reference frequency

frequency spectrum (?)

Which type of visualization would be best if you wanted to determine the frequencies present in a single note?

spectrogram (?)

Which type of visualization would be best if you wanted to examine how frequencies change over time for an entire call?

343 m/s

what is the speed of sound in air?

1500 m/s

what is the speed of sound in the ocean?

doppler shift

as the wavelength shortens the frequency goes up as it’s coming towards you (when an ambulance drives by)

inverse square law

intensity is inversely proportional to the square of the distance from the source. (I= I/r²)

4 → drumming, stridulation/buckling, moving body parts in a fluid and moving fluid medium over body parts

How many types of sound signal generation are there?

woodpeckers on trees

what is an example of drumming?

white storks open their bill to the sky and clack bills together

what is an example of stridulation/buckling?

swim bladders and snapping shrimp

what is an example of moving body parts to produce waves in a fluid?

the vertebrate vocalization system like deep diving seals

what is an example of a moving fluid medium over body parts?

the tension in the vocal cords

What initially produces sound?

cartilage and muscles

in the terrestrial vertebrate respiratory system, the larynx and vocal cords are responsible for producing sound and is a combination of ______ and _______.

their bronchial cavity expands

What special adaptations do pinnipeds have in order vocalize under deep pressure?

acoustic impedance

measure of ease with how a sound wave propagates through a medium

impedance matching

(acoustics) efficient transfer of energy from one medium to another

acoustic impedance in tracheal tube is much higher than in air, so sound vibrations will be reflected back into the trachea when they reach the mouth opening

What is an example of sound signal modification?

many animals have impedance matching structures to help efficiently transfer sound energy

What is a solution to sound signal modification?

air sacs, horns, and fatty melons

What are some examples of impedance matching structures?

odontocete sound production

includes impedance matching → fatty melon (present in dolphins and sperm whales)

burrows and baffles

• leaf=baffle/ insects put their timble structure on the edge of leaf to amplify sound

• in a burrow it’s like a megaphone to amplify sound

burrows and baffles, elongated tracheae and vocal air sacs

what are the 3 types of sound amplification strategies for efficiency?

elongated tracheae

results in a lower admitting frequency and it’s structure is like a pop tube

it is highest when it’s squished up and lowest when it’s elongated fully

what a tracheae is elongated when is the frequency highest/lowest?

vocal air sacs

it inflates like a balloon and it helps create a clearer/louder sound (amplifies)

birds, hooded seals and monkeys

what types of animals use vocal air sacs?