Auditory Development and Music Cognition

Question 1

1- The ear and sound

Answer 1

Outer and middle ear:
When something in the
world moves or vibrates,
it creates a wave that
travels into the auditory
canal. Soundwaves cause
the eardrum to vibrate,
triggering vibrations in
three small bones (incus,
malleus, stapes)

Inner ear:
Soundwaves travel into the
cochlea (from Greek for
“snail shell”), where they
are transduced into
electrical signals

Central nervous system:
Electrical signals travel along
the auditory nerve, through
the brainstem and into
primary auditory cortex
in the right and left
temporal lobes

Question 2

2- Building blocks of sound

Answer 2

Pitch
*We use the word pitch to describe our perception
of the frequency of a wave
*In other words, how many waves will fit in a space?
* The more waves, the higher the frequency
* The higher the frequency, the higher the pitch
*Measured in Hertz (Hz) or as notes on a scale

Melody
* A sequence of pitches that has some logical sense
* Made up of intervals; thus, at least 2 pitches are required
* Has a contour (a pattern of intervals going up and down)
* Tell me your thoughts: why is melody important for speech?
* We use melody in speech to convey meaning and emotion
* This is called prosody, and it is a crucial component of social
communication
* Can I get a volunteer, please? Use melody to convey 2 different
emotions using the words: “You don’t like it”

Beat & rhythm
* Beat refers to our perception of evenly spaced points in a
sequence, sometimes felt as the ‘pulse’
* It’s the points at which you would move along with the music
* e.g., tap your foot, clap, nod your head, shake your hips
* Beats per minute (bpm) = tempo
* Rhythm is the full pattern of temporal intervals in a
sequence
* E.g., Dembow

Timbre (“tamber”)
* The tonal quality of a sound
* Analogous to flavour or colour
*Important in the development of language perception
*Allows us to distinguish between types of sounds
*We can describe timbre with
* Adjectives (e.g., brassy, bright, squeaky)
* Instrument names (e.g., saxophone, guitar, flute)
*We can even describe timbre non-verbally

Question 3

3- What does a fetus ‘hear’?

Answer 3

• The fetus develops in an aquatic environment; high-frequency and loud sounds are
  attenuated by fluid & tissue
• Thus, the fetus is exposed primarily to low-frequency sounds
• When the mother is silent, the most prominent sounds that can be heard are:
  1. Bowel sounds (irregular, ‘popping’)
  2. Maternal heartbeat (regular, slow)
  3. Fetal heartbeat (regular, fast)
  And now, the Uterine Symphony Orchestra presents …
• Why mostly only low-frequency sounds? It has something to do with how cells of the
  cochlea and auditory cortex develop
• They develop in a tonotopic fashion: neurons that respond to specific frequencies are
  grouped together, from low to high, like a keyboard
• The earliest cells to develop are responsive to low frequencies, and the latest cells to
  develop respond preferentially to high frequencies
• The transition from low- to high-frequency auditory processing happens gradually
  throughout infancy and is an essential part of proper sensory development

Question 4

4- How does the auditory system develop?

Answer 4

• In the first 20 weeks of pregnancy, the fetus is unresponsive to sound
• Soundwaves cannot yet be transduced into electrical signals and therefore do
  not reach the auditory cortex for processing
• This is because the development of the cochlea is incomplete
• At 20 weeks, the neural pathway to the auditory cortex becomes
  functional; its development continues up to 2 years after birth
• Between 20-25 weeks, the first responses to sound can be recorded via
  ultrasound
• By 35 weeks, cochlear development is mature
• At term (40 weeks), basic auditory abilities are functional

Question 5

5- Basic auditory abilities

Answer 5

• Already developed at birth
• Localization: ability to perceive the spatial location of a sound source
• Babies are worse than adults because of their smaller head size
• Let’s try it! Turn your head in the direction each sound is coming from
• Identification: ability to perceive discrete speech sounds (phonemes)
• Important for the development of language
• Let’s try it! What do you hear?
• Discrimination: the ability to hear differences between sounds
• Important for the development of language and music
• Let’s try it! Are these sounds the same or different?

Question 6

6- The importance of pitch in development

Answer 6

• Newborns can discriminate a wide range of pitches (from 20-20,000
  Hz) but this range gets narrower as children get older
• Why does this process of perceptual narrowing of pitch occur?
• Reason 1: attachment. Being able to bond with caregivers is more likely to
  ensure survival; thus, the auditory system needs to be optimally sensitive to
  pitches emitted by caregivers
• Reason 2: language. Infants need to be able to adopt their native
  language(s); thus, a wider range of sensitivity ensures optimal language
  acquisition
• Pitch is also used by parents to influence infant attachment
• Caregivers sing to their infants in a higher-pitched and slower tone
• Infants prefer infant-directed singing over adult-directed singing

Question 7

7- Case discussion: What to do as head of NICU?

Answer 7

THE FACTS:
* In utero, high-frequency sounds are attenuated by fluid & tissue
* In preterm infants (born <35 weeks), high-frequency sounds are amplified
* The neonatal intensive-care unit (NICU) environment:
* Overexposure to high-frequency sounds (e.g., ventilators, fans, pagers, monitors,
alarms) and underexposure to low-frequency sounds (e.g., the uterine environment)
* The transition from low- to high-frequency auditory processing happens gradually
throughout infancy and is an essential part of proper sensory development
* Preterm infants do not experience this gradual transition
* Preterm infants are more sensitive to high-frequency sounds, which can be toxic to
development of the auditory cortex
* This may have adverse effects on language & musical abilities
* You are the head of the NICU. How do you deal with this issue?

Provide low-frequency sound exposure to
preterm infants, to compensate
* Researchers suggest that for babies born prematurely, it could be beneficial to expose
them to primarily low-frequency sounds after birth
* A 2015 study sought to investigate this claim. Researchers took a group of 40 mothers
who’d had babies at 30 weeks
* Babies in the experimental group received 3h per day of exposure to a uterine
environment soundscape (the mother’s voice + heartbeat) for the duration of their
NICU stay (test your knowledge – what sounds did they forget?)
* Babies in the control group received treatment as usual (hospital sounds)
* Even though there were no differences before the intervention, babies in the
experimental group showed faster development in the auditory cortex, as measured
by cranial ultrasound
* This was taken as evidence that auditory plasticity can be evoked in preterm infants
through exposure to realistic uterine soundscapes

Question 8

8- Melody abilities: discrimination & singing

Answer 8

• Discrimination tasks measure the ability to detect differences
• Discrimination can be tested for any property of melody (e.g., interval, contour, timbre)
• Let’s try! Listen to the sequences and say whether they are the same or different
• Melody discrimination ability reaches adult levels by age 10-11
• Singing tasks measure the ability to match or repeat pitches or sequences
• Let’s try! Sing this pitch
• Singing ability peaks by age 12
• In adolescence singing is influenced by several factors – what are your guesses?
  1. Musical training
  2. Puberty
  3. Shyness
  4. Music listening

Question 9

9- Special melody ability: Absolute pitch

Answer 9

• Some people can sing, name, or identify a pitch without reference to
  another pitch; this is called absolute pitch (AKA perfect pitch)
• Very rare: 1 in 10,000 people are born with it
• Provides evidence of a critical period in auditory development
• It cannot be developed without ear and memory training AND this training must
  begin in childhood
• If a child hasn’t acquired absolute pitch by about 11 years old, it cannot be
  acquired fully
• Let’s watch: Dylan Beato, age 11
• Began ear and memory training for pitches at age 2-3
• Knows the absolute position and sound of every pitch in the scale
• Can sing or identify notes and even multiple notes at once

Question 10

10- Rhythm abilities: perception and synchronization

Answer 10

• Beat perception tasks measure the ability to find the beat
• Like melody perception, discrimination tasks are used (logic: if you can detect a
  difference from the beat, you’ve detected the beat)
• Let’s try! Beat alignment task: listen to the two clips (each is a musical excerpt with
  a superimposed beat). Are they the same or different?
• By age 5, children can detect beat misalignment for rhythms that are culturally
  familiar (Einarson & Trainor, 2016)
• Synchronization tasks measure the ability to move in time (e.g., tap, click
  a mouse) with an external stimulus
• Motor development occurs from head to feet and from the midline of the body
  out; thus, movements of the head and trunk → clapping → marching
• Synchronization is multimodal: it engages multiple regions of the brain (auditory,
  motor, memory)
• By age 4, children can synchronize movements to a steady beat
• Let’s try! Clap, snap or stomp to the beat
• However, they cannot synchronize well to rhythmic sequences
• Let’s try! Clap, snap or stomp to the full rhythm
• Overall, children’s rhythmic abilities develop more slowly and are more
  variable than adults. Why do you think?
• They are multimodal (implicate more than one region of the brain)
• Some of these brain regions do not mature fully until late adolescence
• Cultural familiarity also plays a role in rhythmic ability
• For example: Moroccan chaabi (personal anecdote)

Question 11

11- A distinction: perceived vs. felt

Answer 11

• Perceived emotion is inferred
• Linked to features of the musical stimulus
• e.g., pitch, tempo, rhythm, timbre, lyrics
• Felt emotion is evoked
• Linked to activation of the nervous system
• Perceived and felt emotion can be different: we often experience
  pleasure listening to sad music
• Let’s try!

Question 12

12- Can children perceive musical emotions?

Answer 12

• Yes! Tested through recognition tasks that can be nonverbal (e.g., circle
  an image that corresponds to the emotion) or verbal (e.g., write or tell
  me the emotion)
• By age 3-5 children can recognize happy and sad music
• Recognition is better for happy-sounding music, perhaps reflecting
  the frequency of child-directed speech in this age group
• By age 11, the ability to recognize happy & sad music reaches adult
  levels; by contrast, even adolescents can have difficulties recognizing
  fear and anger in music
• Children recognize emotion in music just as well as in speech

Question 13

13- Can children feel musical emotions?

Answer 13

Can children feel musical emotions?
* Yes! By age 1, about 90% of infants move or “dance”
to music (even though not synchronized)
* They move more to music than speech and more to familiar
than unfamiliar songs
*Children’s musical movements are frequently
accompanied by smiling and laughter
* This is taken as evidence that children, like adults, may feel
a pleasurable urge to move to music
* This urge to move to music is driven by a phenomenon known
as groove

Question 14

14- Groove: Influence of groove on children’s dancing

Answer 14

• Certain musical characteristics are consistently associated with groove
• One common example is syncopation: a pattern of emphasis off the main beat
• Let’s hear that rhythm from earlier!
• None of the “cha” sounds are on the beat (“boom”); this is syncopation
• Groove is most strongly felt with a medium level of syncopation
• Too much and it’s complicated, too little and it’s boring
• In adults, groove plays a pivotal role in producing and
  maintaining the urge to dance
• High-groove music is associated with more
  movement & better timing accuracy
• High-groove music is associated with higher
  pleasure and reward
• How does groove affect children’s dancing? In other words
• Is high-groove music associated with more movement & better timing
  accuracy?
• Is high-groove music associated with higher pleasure and reward?
• Experimental study by a group of CDN researchers (Kragness et al., 2022):
• 78 children aged 3-6
• Parents were asked to film their children having a “dance party”
• Four conditions:
  1. High-groove music, slow tempo
  2. High-groove music, fast tempo
  3. Low-groove music, slow tempo
  4. Low-groove music, fast tempo
• Before we reveal the results, let’s watch! (Video abstract provided by authors)

Results
* Is high-groove music associated with more movement?
* YES! More movement and more energetic movement
* Is high-groove music associated with better timing accuracy?
* YES! Although overall, timing accuracy is quite low given age
* Is high-groove music associated with higher pleasure and reward?
* In fact, children expressed joy in 75% of trials, irrespective of groove
* Thus, groove seems to play a similar role in producing and
maintaining the pleasurable urge to move in children and adults