2. How Does theHow Does the
Walrus Hear?Walrus Hear?
What Does theWhat Does the
Walrus Say?Walrus Say?
3. Walrus HearingWalrus Hearing
Little knownLittle known
Only one study andOnly one study and
probably not entirelyprobably not entirely
accurate.accurate.
AmphibiousAmphibious
AerialAerial
UnderwaterUnderwater
4. Outer and Middle EarOuter and Middle Ear
Sound vibrations travel to the pinna.Sound vibrations travel to the pinna.
Sound is channeled to the ear drumSound is channeled to the ear drum
(tympanic membrane)(tympanic membrane)
Sound is amplified and travels across 3Sound is amplified and travels across 3
bonesbones
Malleus, Incus, StapesMalleus, Incus, Stapes
5.
6. The Inner EarThe Inner Ear
CochleaCochlea
Oval windowOval window
Doorway to CochleaDoorway to Cochlea
Basilar MembraneBasilar Membrane
Vibrations lead to pitch and tone detectionVibrations lead to pitch and tone detection
Hair CellsHair Cells
Bend as the basilar membrane rubs togetherBend as the basilar membrane rubs together
Auditory NerveAuditory Nerve
Hair cells that bend release CaHair cells that bend release Ca++
that relays thethat relays the
message to the brain.message to the brain.
12. Do they Talk?Do they Talk?
NO!NO!
Walruses communicateWalruses communicate
SoundsSounds
TouchTouch
SmellSmell
BehaviorBehavior
13. ActivityActivity
Break into groupsBreak into groups
Come up with sounds that you think aCome up with sounds that you think a
walrus would makewalrus would make
Must give a demo of the soundMust give a demo of the sound
Why does this sound matter?Why does this sound matter?
14. My ResearchMy Research
Study PinnipedsStudy Pinnipeds
Pacific WalrusPacific Walrus
Pacific Harbor SealPacific Harbor Seal
California Sea LionCalifornia Sea Lion
Record Underwater SoundsRecord Underwater Sounds
Look for Ultrasonic frequenciesLook for Ultrasonic frequencies
Catalog the Repertoire at HigherCatalog the Repertoire at Higher
FrequenciesFrequencies
15. BackgroundBackground
Males are typicallyMales are typically
vocal to attractvocal to attract
females duringfemales during
breeding seasonbreeding season
Pick up linePick up line
No studies onNo studies on
femalesfemales
Very vocal animalsVery vocal animals
16. GoalsGoals
To record underwaterTo record underwater
sounds to look forsounds to look for
ultrasonicultrasonic
components andcomponents and
potential use towardspotential use towards
echolocation.echolocation.
To observe behaviorsTo observe behaviors
in attempt toin attempt to
understand functionunderstand function
of sounds produced.of sounds produced.
17. MaterialsMaterials
Ithaco 605 Hydrophone-Ithaco 605 Hydrophone-
Ultrasonic frequencyUltrasonic frequency
response.response.
DELL XPS M140 Laptop.DELL XPS M140 Laptop.
Goldwave sound analysisGoldwave sound analysis
program and recordingprogram and recording
software.software.
Spectrogram soundSpectrogram sound
analysis program.analysis program.
18. MethodsMethods
Recordings takenRecordings taken
during Spring andduring Spring and
Summer months ofSummer months of
2006 at Brookfield2006 at Brookfield
Zoo between 6-10AM.Zoo between 6-10AM.
Behavioral notesBehavioral notes
taken as needed astaken as needed as
well as video.well as video.
19. What do I do with theWhat do I do with the
datadata
Listen to sound filesListen to sound files
Identify SoundsIdentify Sounds
Analyze withAnalyze with
SoftwareSoftware
Identify certainIdentify certain
featuresfeatures
Run statistical testsRun statistical tests
Similar and differentSimilar and different
Activity if time runs out. Ask the students to think of ways to test the cochlea (gello and sound vibrations). Discuss how to become a marine scientist in Illinois and how to get into the field. Skills scientists need etc.