Respiratory sounds Flashcards
Give the 2 methods of respiratory sound.
Non-vocal- Breathing sounds
Vocal- Vocalisations
Where does respiratory sound production occur ?
In the mammalian larynx
Describe the way respiratory sound is produced
Vocal folds are closed
Air flow increases
VF begin to open
Air pressure will increase Release puff of air
What is the main feature of the sound produced by respiratory means ?
Will be rich in overtones
Not a perfect sound wave.
Describe the sound produced by the Indri (lemur)
Fundamental freq. 750-1100 Hz
Individuals will usually duet
Many harmonic overtones
Describe the sound produced by the African Elephant.
Fundametnal freq. 15-20 Hz
Greeting rumble
Many harmonic overtones
What sepecies produces the lowest frequency mammalian noise ?
African elephant.
Enabled by large voice box
What does the vibration frequency of the vocal folds depend on ?
The length of the vocal folds.
i.e. The longer the fold, the slower the vibration
What is voice box size proportional to ?
The length of the animal.
What will the frequency of noise be in a larger animal ?
Lower frequency
Larger voice box, larger vocal folds, slower vocal fold vibration
Which species do not produce the frequency expected ?
Horses.
Large mass but higher frequency than expected.
Describe the 2 vocal elements of the hippopotamus.
Fundamental frequencies 190Hz, Harmonic overtones
AND
Breathing elements (inhale)
No harmonic structure.
Where do hippopotamuses propagate noise ?
Half in air and half under water
Audible under water.
What group of sounds in the human language have harmonic structure ?
3 vocal vowels, ‘a’ ‘ou’ ‘i’
Fundamental frequency- 100Hz
Vowels have many harmonic overtones,
What are Formants ?
Overtones with the most energy
Consonants ‘c’, ‘st’, ‘s’ have harmonic structure.
True or False ?
False,
Where are vowels formed ?
In the voice box
Have many harmonic overtones.
How does the mammalian larynx differ from a birds ?
Have an Avian Syrinx
2 Vibrating valves
Have independent control over both sides,
What is the benefit to the bird of having independent control of both sides of the Syrinx ?
Can sing 2 different sounds at the same time
Can alternate, mid-element
Diff frequency ranges on both sides.
Describe the song of the linnet
Highly complex
Dense series of harmonics
Low fundamental frequency
Describe the song of the brown headed cow bird.
Rapid clusters of notes
Right syrinx- High frequency
Left syrinx- Low frequency
Able to switch between valves in one element
Why is sound production so important to aquatic mammals ?
Too dark for vision
Olfaction is hampered by slow diffusion
Define olfaction
Sense of smell
What is the function of sound for Baleen Whales ?
Communication
i.e Humpback Whale
What is the function of sound for toothed Whales ?
Biosonar
i.e Bottlenose dolphin
What is special about the sound produced by humpback whales ?
Males Sing- for hours
Tradition- new song every year
How do humpbacked whales produce sound ?
Still unclear
Have larynx but no vocal calls
What are the problems with humpbacked whales communicating at certain depth ?
Air is compressed as they travel to this greater depth
Have to have large intake of O2
How do humpbacked whales utilise all available air ?
Produce sounds at inhale and exhale
Recycle air, by pumping it back and forth
Bottlenose dolphins produce sounds via their larynx
True or False ?
No Larynx in toothed Whales
Use phonic lips and nasal airway.
Describe how dolphins produce sounds for echolocation.
Monkey lips- produce clicks
They are found in the nasal airway
Air is forced In from below forcing the ML to clap shut
What is the function of the out of water communication that dolphins produce ?
No function, create it due to training by humans.
What determines sound radiation patterns in air ?
The shape of the mouth,
Airborne sound is reflected by body tissue.
How does the howler monkey affect its sound radiation pattern ?
by funnelling it using its lips.
The close the impedances of 2 media……
The better sound passes from one medum to the other.
Give the impedance p*c ratio of Air and Water
A : W
1 : 3600
All airborne sound enters water and vice versa
True of False ?
False.
The impedance ratios are very far apart (1, 3600).
Give the Absorption ratio of air to water
Air : Water
1000: 1
Sound travels much further in air
True or False
False,
Sound travels further in water, hardly absorbed in comp. to air
Why are sound radiation patterns not affected by body tissue under water ?
Body tissue and water have a similar impedance
Sound in water will pass straight through tissue.
How do marine mammals reflect sounds underwater ?
Using air filled cavities
How do marine mammals manipulate underwater sound ?
Use oily/fatty tissue
Their density differs from water
Manipulate sound like optic lense
Give examples of structures in marine mammals which have developed to manipulate sound.
Dolphins- Melon
Sperm Whales- Nose
Hippopotamus- Double chin
