How do birds make sounds? L27. Mate Calling in …...resonator (like a tuned pipe) Does the vocal tract act like an open resonator? An organ pipe which is open at each end resonates

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L27. Mate Calling in Animal Communication: Birdsong 2Communication: Birdsong 2

BioNB 4240

Cornell University

© Carl D. Hopkins

How do birds make sounds?

Medial tympanic membranes

Medial labiaLateral labia

Larsen & Goller (2002) JExpBiol. 205(1) 25

Endoscopic visualization shows the importance of the lateral labia and medial labia in vocal production.

Goller and Larsen (2001)


a) respiration

b) strong stimulation

c) labia near close aperture

d) i ti i

Endoscope shows movements of lateral and medial labia.

d) respiration again

e) respiration

f) stimulated

g) stimulation of on vTB


relaxed (respiration) rostrad movement of syrinx. medial and

old model (medial tympaniform membrane)

e a ed ( esp at o )lateral labia enter air passage.

crow

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Does the vocal tract act like a resonator?

Q? Does the vocal tract of bird act like a resonator (like a tuned pipe)

If yes, then two different resonant frequencies are y , qimpossible (unless harmonically related).



Does the vocal tract act like an open resonator?

An organ pipe which is open at each end resonates for sound waves where L = n λ / 2, n=1,2,3…

Length of pipe,L = n λ / 2 where n = 1, 2,3,4…f = v / λ, (v = velocity of sound)f = nv/2L where n = 1, 2,3, 4,5

http://home.no/jjdamm/stageac/organpipe.html

plot of sound pressure

Does the vocal tract act like a closed resonator?Open at one end, closed at the other.

Standing wave established. Node at closed end of pipe, anti node at open end. L ength of pipe = n λ / 4 where n = 1, 3, 5,f = nv/4L where n = 1, 3, 5 (v = velocity of sound)L=0.569 m, f = 151 Hz, 453 Hz, 755 Hz

open end closed end

Pan Fluteopen

closed

Tube number 1 2 3L (mm) 53 144 195F1 1335 581 430F3 4285 1722 1270predicted F 1622.642 597.2222 441.0256F3 predicted 4867.925 1791.667 1323.077

error 82.27326 97.28372 97.588.02519 96.11163 95.98837

Closed tube resonanceFlute of pan

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Pan and Syrinx

Anonymous after Hendrik Goltzius (Dutch, 1558-1617), Pan Pursuing Syrinx, Who is Changed into a Reed, 1589. (Illustration for Ovid’s Metamorphoses)

in air

He Ox

Nowicki, S. (1987) Nature. 1987 Jan 1-7;325(6099):53-5.

Vocal tract resonances in oscine bird sound production: evidence from birdsongs in a helium atmosphere.

in air

He Ox

Air

Nowicki, S. (1987) Nature. 1987 Jan 1-7;325(6099):53-5.

He + Ox



If yes, then two different resonant frequencies are y , qimpossible (unless harmonically related).

Helium experiments (Nowicki) uncovers higher harmonics when singing in light air (Implies some resonant filtering in normal air)

Birds are also capable of singing two unrelated notes at once (implies that fundamental frequency is not a vocal tract resonance).

Brown thrasher produces two unrelated frequencies

Two frequencies (clearly unrelated) at same time (one bird).

Beat (amplitude modulation) between two similar tones.

spectrogram

pressure transducer

Brown thrasher two voice vocalization is clearly composed of four two-voice syllables, each with independent frequency modulation. (Suthers et al, 2004).

air flow transducer

right side

voice

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Brown thrasher two voice vocalization is clearly composed of four two-voice syllables, each with independent frequency modulation. (Suthers et al, 1004).

X-ray movie of cardinal vocal tract during song production reveals modulation of vocal tract resonances during singing.

Neural control of syrinxNottebohm F, 2005 The Neural Basis of Birdsong. PLoS Biol 3(5)

The Song System of SongbirdsNucleus HVC feeds information into two pathways that ultimately lead to the neurons in the tracheosyringeal half of the hypoglossal nucleus (nXIIts) that project to vocal muscles. HVC projects to nucleus RA directly (PDP), and indirectly via Area X, the dorsolateral anterior thalamic nucleus (DLM), and LMAN (AFP) in a manner that shares similarities with the mammalian pathway cortex→basal ganglia→thalamus→cortex.

Effect of unilateral lesion of hypoglossal nerve

normal chaffinch song

same chaffinch after cutting one sideh l l

Right XII lesion left XII lesion

hypoglossal nerve

Lesions to the right side cause drop outs of some syllable types, but not all.

In chaffinch, the left side does most of the singing.

Nottebohm, F. (1971). Neural lateralization of vocal control in a passerinebird. I. Song. J. Exp. Zool. 177, 229–262.

Similar effect in White Crowned Sparrow

Nottebohm, F. (1971). Neural lateralization of vocal control in a passerine bird. I. Song. J. Exp. Zool. 177, 229–262.

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Broad outline of neural control pathways:

nXII tracheosyringealis nucleus in brainstem (motor neurons)

RA: robust nucleus of archistiatum (telencephalon)

HVC: higher volcal center (telencephalon)

Evidence to support anatomy:

Lesions to XII, RA, or HVC disrupt song (Nottebohm).tract tracing (silver degeneration)multicellular recordings

Lesions to HVC on left and right produce song deficits, without affecting respiration

Laterality in the HVclesions in the HVc of canary show that laterality extends up to HVc (Nottebohm)

pre-op

post right HVc lesion

pre-op

post Left HVc lesion

However, lesions to HVc before song crystallization right side takes over the left side’s function.

trill2 octave sweeps

Northern cardinal song consists of one to several syllables, usually FM sweeps.Each syllable has a distinctive air-flow pattern.minibreaths replenish air after each syllable, except for trill.Unusual 2 octave sweep.Long sweep reveals alternation of R and L syrinx.Fundamental >3.5 kHz Right sideFundamental <3.5 kHz Left side.

FL

FR

Sound, Flow left, flow right, pressure during FM sweeps in Northern Cardinal.

The Song System of SongbirdsNucleus HVC feeds information into two pathways that ultimately lead to the neurons in the tracheosyringeal half of the hypoglossal nucleus (nXIIts) that project to vocal muscles. HVC projects to nucleus RA directly (PDP), and indirectly via Area X, the dorsolateral anterior thalamic nucleus (DLM), and LMAN (AFP) in a manner that shares similarities with the mammalian pathway cortex→basal ganglia→thalamus→cortex.

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Early studies reveal neural correlates of complex motor control in birds

1) Size of HVc in different individuals, with different repertoire sizes, correlates with the size of song repertoire.

2) Size of HVc under goes seasonal changes (gets larger in spring)larger in spring)

3) HVc and RA are often sexually-dimorphic (in some species, both male and female are equally good songsters i.e. duetting species)

4) Hormones affect singing: Testosterone stimulates the growth of song centers- volume of HVc is reduced in male castrates- volume increases again in implanted female castrates.

Neural correlates of birdsong

1. Chronic recordings of cellular activity in HVc, NiF, RA in awake birds show many units that are time-locked to song.

2 Latency analysis shows sequence:2. Latency analysis shows sequence: NIF – HVC – RA

3. Some units in HVc fire prior to certain syllables; others are more general and fire in response to general song related activity.

4. Single unit recordings from many neurons in RA reveal song element coding by “ensembles”

Spikes fromSpikes from many neurons in RA while singing (Zebrafinch)Leonardo and Fee (2005) J. Neurosci.

Leonardo and Fee (2005) J. Neurosci.

Leonardo and Fee (2005) J. Neurosci. Margoliash, D. (2005) Nature Neurosci. 8 (5): 546-8

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How do birds make sounds? L27. Mate Calling in …...resonator (like a tuned pipe) Does the vocal tract act like an open resonator? An organ pipe which is open at each end resonates