the basics of sound physics

what is sound?

a vibration that moves as a wave through a medium

does sound travel quicker through lair, liquid, or solid?

solid

why do animals swimming at depths prefer to explore their environment with sound?

sound helps with navigation, hunting, and communication

how do marine carnivores produce sound?

their larynx similar to a humans

what is frequency

# of waves produced in 1 second (hertz)

what mechanisms do mysticetis use to produce sound

loud, U-fold, Laryngeal sac

what is a laryngeal sac?

expandable pouch connected to the larynx

sound production mechanisms in odontoceties

echolocation

how does echolocation mechanism work?

larynx and air sac, phonic lis, melon

what are phonic lips?

tissue inside the nasal cavities that vibrate to produce a clicking sound

what does the melon do?

acts as a lens to focus and direct sound waves

what is echolocation?

high frequency sound wave, reflects sound off objects in the water and detected by the dolphin

what is thee distance of echolocation?

can detect things only a few cm in size greater then 10m away

what is the purpose of echolocation?

navigation and hunting

what are the types of sound communication for marine mammals?

intrasexual (same sex), intersexual (M/F), Mother/calf cohesion, Group cohesion, Alerts/danger, Individual recognition

how does hearing work in marine mammals when on land?

sound waves enter through outer ear and vibrate the tympanic membrane and middle ear ossicles

tympanic

membrane that separates outer ear from middle ear

ossicles

three tiny bones, incus (anvil), malleus (hammer), stapes (stirrups)

hearing in sirenians

unclear, fatty tissue separates the external auditory meatus and tympanic membrance

hearing in cetaceans

no external ears, mysticete plug with wax

how do odontocetes transmit sound?

odontocetes lower jaw transmits sound to middle then- inner ear

how do mysticetes transmit sound?

likely through skull bone conduction