The Neurobiology of Children’s Hearing

Why the Entertainment Industry Undermines Infants’ Cognitive Potential and How Acoustic Ecology Saves Their Mental Health

A scientifically unfounded and extremely dangerous stereotype has taken root in modern culture: that music for infants and young children should be deliberately simplified, high-pitched, and synthetic. The commercial children’s content industry mass-produces so-called “lullabies” and entertainment audio tracks using electronic sound generators, shrill bells, primitive marching rhythms, and aggressive compression. This approach not only lacks any therapeutic value but also constitutes a form of covert acoustic aggression. By penetrating a child’s immature nervous system, such content exploits fundamental biological vulnerabilities, causing proven damage to the brain’s executive functions, the hypothalamic-pituitary-adrenal axis, and sensory integration processes.

A quick note for parents: If something is toxic to an adult with a healthy, fully developed brain, it’s twice as toxic for a child. A toddler’s auditory system is like their digestive system: they don’t yet have immunity against aggressive digital noise. Music isn’t just a way to keep them quiet - it’s nourishment for the nervous system. So why do we keep playing for our children the very things that give us a headache within 10 seconds?

A thorough analysis of empirical data from the fields of neuromusicology, cognitive psychology, and acoustic ecology allows us to completely debunk this commercial myth. A true lullaby and sleep music are not merely a primitive set of sounds, but a complex neurophysiological synchronization tool developed through human evolution. Contrasting toxic commercial audio content with live acoustic music (specifically, a therapeutic quartet consisting of a harp, flute, cello, and piano) reveals a colossal difference in their effects on neuroplasticity, cortisol levels, and the formation of higher-order cognitive networks in infants.

The Evolutionary and Physiological Architecture of a True Lullaby

To understand the true value of music for brain development, it is necessary to examine the ontogenesis of the auditory system. The auditory system begins to function as early as the prenatal period, around 20–24 weeks of gestation, when the primary tonotopic organization of the cochlea in the inner ear and the auditory pathways of the brainstem is formed. From this point on, the fetus learns to recognize acoustic patterns. In the womb, the fetus is in a protected acoustic environment, where the amniotic fluid acts as a natural low-pass filter. This filter effectively attenuates sharp, high-frequency external noises, directing the developing brain’s attention to the rhythmic beating of the mother’s heart, the sound of blood flow, and the low-frequency resonances of the mother’s voice.

At birth, especially in the case of premature birth, this physiological sound barrier suddenly disappears, and the infant’s nervous system is confronted with a massive, chaotic flood of unfiltered acoustic information. Historically and evolutionarily, it is traditional lullabies that have served as a therapeutic bridge between the safety of the womb and the acoustic chaos of the outside world. Their effectiveness is not due to cultural traditions, but to strict neurophysiological laws.

Analysis of clinical data shows that maternal humming without clearly articulated words has a more pronounced regulatory effect on an infant’s cardiorespiratory system than ordinary speech or singing with lyrics. Such low-frequency vocal intonation significantly reduces the infant’s average heart rate (HR) and optimizes the critically important ratio of oxygen saturation (SpO2) to heart rate. While speaking or singing words carries a high cognitive and emotional load that may unintentionally convey the mother’s anxiety, rhythmic cooing or humming conveys a pure signal of biological safety, shifting the newborn’s autonomic nervous system from a state of sympathetic arousal (the “fight-or-flight” response) to parasympathetic rest.

Studies conducted in neonatal intensive care units (NICUs) confirm that acoustic stimulation with live lullabies promotes deeper sleep, improves social and emotional development, and aids in pain management. For example, the use of lullabies (including classical ones, such as Brahms’s lullaby) leads to a statistically significant improvement in blood oxygen saturation levels and stabilization of breathing compared to control groups that did not receive musical accompaniment. Music acts as a predictable and stable source of stimulation that counteracts the chaos of the hospital environment and stimulates the release of endorphins, leading to a reduction in sympathetic nervous system activity and a decrease in oxygen consumption.

Tempo 60–70 BPM: The Biological Metronome and Synchronization

The fundamental parameter of therapeutic music is its tempo. The physiologically grounded rhythm of a true lullaby or soothing melody ranges from 60 to 70 beats per minute (in musical terms, Largo or Adagio). This range was not chosen at random: it corresponds exactly to the heart rate of a mother in a state of deep rest.

The process of synchronization (entrainment) between the external acoustic rhythm and the infant’s internal biological oscillators occurs at the subcortical level. When a child hears a rhythm that mirrors a calm heartbeat, their brain interprets this pattern as a marker of absolute environmental safety. Audio stimulation that mimics the sounds of a mother’s heartbeat, combined with soft background noises, not only stabilizes breathing and heart rate but also promotes faster weight gain in premature infants. The mechanism behind this phenomenon lies in a reduction in the energy expended on stressful and chaotic motor responses: under the influence of appropriate music, infants’ excessive motor activity decreases by an order of magnitude, allowing the freed-up energy to be directed toward physical growth and development.

The Anatomy of Acoustic Toxicity:

Synthetic Music and Cognitive Overload

In stark contrast to the principles of neuromusicology stands the modern commercial children’s content industry. Projects that create mass-market 3D animations and their accompanying soundtracks aim to capture a child’s attention as much as possible. This content is optimized not for the development of cognitive skills, but for aggressive sensory overload, which inevitably leads to the exhaustion of the immature nervous system.

Analysis shows that mass-market products labeled as “music for toddlers” suffer from profound structural flaws. Instead of training the brain to recognize subtle harmonic relationships, they offer auditory “fast food” that causes addiction and dysregulation.

High frequencies, compression, and HPA axis response

A child’s brain - particularly the frontal lobes, which are responsible for inhibiting and filtering stimuli - is in the early stages of development. Infants have a limited ability to ignore irrelevant information. Commercial children’s music is characterized by aggressive hyperstimulation along three key acoustic vectors:

• A high-frequency synthetic spectrum. Most commercial tracks are dominated by synthesizer sounds that mimic xylophones, piercing whistles, and bells. On a physiological level, high frequencies (especially synthesized ones) are perceived by the brain not as a soothing signal, but as an evolutionary marker of alarm or a scream. Studies on acoustic effects show that continuous exposure to high-frequency noise (8,000 Hz and above) leads to a significant increase in blood cortisol levels in more than 65% of subjects within just 30-40 minutes. In the NICU setting, high-frequency noise from medical equipment (above 500 Hz) can disrupt the normal tonotopic tuning of the cochlear hair cells and hinder subcortical and cortical auditory development, since the cochlear neurons are still in the process of migration during this period. The use of a similar frequency spectrum in content intended for healthy infants triggers a comparable stress response.

• The “Loudness War” and Audio Compression. Modern media content, including content for children, is produced using extreme dynamic compression - a practice known in sound engineering as the “Loudness War.” The essence of this process lies in the artificial elimination of dynamic range: the quietest sounds are amplified, while the loudest are limited, resulting in music that becomes a dense, continuous wall of sound. Compressed music is completely devoid of natural acoustic micro-pauses and breathing. An infant’s hearing, when exposed to such a hyper-compressed signal, does not receive millisecond-long rest periods, leading to rapid auditory and central nervous system fatigue.

  
  

• Simplicity and march-like rhythms. Standard children’s songs universally employ a monotonous, inflexible 4/4 time signature. Such music lacks agogics (natural micro-variations in tempo), which are characteristic of live human performance. Strict quantization of sound turns the melody into a mechanical stimulus that does not develop neural networks but merely “drowns out” other sounds in the environment.

To put it simply: Electronic beeping bells and cheap speakers blaring generic “lullabies” sound less like a fairy tale and more like an alarm to a baby’s brain. The subcortex interprets this piercing ringing as a screech or a danger signal. Instead of promoting relaxation, this kind of music triggers the body’s internal alarm - the child falls asleep not out of calm, but out of exhaustion and stress.

The result of such auditory bombardment is classic sensory overload. When the volume of incoming auditory and visual information exceeds the nervous system’s processing capacity, the child’s body cannot smoothly switch from the sympathetic to the parasympathetic state. The hypothalamus releases corticotropin-releasing hormone (CRH), which stimulates the pituitary gland to secrete adrenocorticotropic hormone (ACTH), which, in turn, causes the adrenal glands to release massive doses of cortisol and epinephrine into the bloodstream.

Chronic or frequently recurring elevations in cortisol levels in infants are a potent neurotoxic factor. High cortisol impairs the regulation of sleep phases, hinders normal synaptogenesis in the prefrontal cortex and hippocampus, and leads to hyperexcitability. Externally, this manifests as unprovoked tantrums (meltdowns), constant tearfulness, difficulty falling asleep, and the child’s inability to play independently. When aggressive content is suddenly turned off, the child experiences a drop in stimulating dopamine levels against a backdrop of already sky-high cortisol, leading to acute behavioral dysregulation.

Executive Function Exhaustion: Empirical Evidence

The destructive impact of overstimulating media content has been rigorously quantified. One of the most authoritative studies in this field was conducted by Lillard and Peterson in 2011 and published in the journal Pediatrics. During the experiment, 60 four-year-old children were randomly divided into three groups: the first group watched a fast-paced, highly stimulating cartoon (“SpongeBob SquarePants,” where scenes changed on average every 11 seconds); the second group watched a calm, educational cartoon with smooth transitions (“Kaiyu,” with scene changes every 34 seconds); the third group engaged in free drawing.

The exposure lasted only 9 minutes. Immediately afterward, the children took a series of tests to assess executive functions (Tower of Hanoi, backward digit span, delay of gratification). The results were striking: children in the hyperstimulating cartoon group showed a statistically significant, sharp decline in executive functions compared to the other two groups.

Executive functions are the brain’s control system, providing working memory, cognitive flexibility, and the ability to inhibit impulses. The rapid frame rate and chaotic soundtrack literally depleted the children’s cognitive resources, as their brains were forced to continuously expend energy encoding information that was changing at an unnaturally fast pace. Synthetic music with rapid, aggressive transitions and an overloaded frequency spectrum produces a similar effect. It fosters a “music video”-style perception in children, reducing their ability to sustain concentration over time.

Predictive Coding and Acoustic Complexity

To gain a fundamental understanding of why primitive synthetic music hinders cognitive development, while complex acoustic music acts as a catalyst for neurogenesis, it is necessary to incorporate the theory of predictive processing, developed by neurobiologist Karl Friston, into the analysis.

According to the predictive coding paradigm, the brain is not a passive receiver of information. On the contrary, it is an active “Bayesian inference machine” that continuously generates probabilistic top-down models of the environment and compares them with bottom-up sensory signals. Learning, development, and the formation of new neural connections occur exclusively at moments when a controlled “prediction error” arises - when the incoming acoustic signal differs slightly from what the brain expected to hear.

Neurophysiological experiments demonstrate that infants possess an astonishing innate capacity for statistical learning. Analysis of brain activity using temporal response functions shows that newborns are capable of forming musical expectations based on rhythmic statistical patterns. Interestingly, at birth, infants are much better at discerning rhythmic structure than melodic structure: their brains actively respond to real music with a natural rhythm, while ignoring chaotically jumbled sounds.

When a child regularly listens to primitive commercial music with a perfectly regular, machine-like (quantized) march rhythm and no overtones, their brain instantly constructs a comprehensive model of that sound. The prediction error is reduced to zero. As a result, cognitive stimulation ceases; the brain enters a standby mode, and the development of neural networks slows down.

In contrast, live acoustic music, especially that which uses syncopated rhythms or jazz elements (Afrobeat, Bossa Nova, acoustic folk), contains an infinite number of micro-variations in tempo, dynamics, and timbre. Syncopation and complex polyrhythms cause the basal ganglia and cerebellum to work intensively, creating an optimal level of prediction error (Optimal Prediction Error). The child’s brain becomes engaged in the process of constantly “deciphering” the rhythm, entering a state of deep immersion and intellectual pleasure - the “flow” (Flow state) as described by Mihaly Csikszentmihalyi. This is fully consistent with Lev Vygotsky’s principle of the “zone of proximal development”: the sensory stimulus must be complex enough for the brain to “reach” for it, thereby developing executive functions, but not so chaotic as to cause frustration.

What this means in practice: A child’s brain is wired to constantly try to predict what will happen next. When we play a two-chord song with a monotonous beat, the brain drifts off out of boredom and becomes dull. A lively, complex rhythm (such as a smooth jazz or acoustic groove) activates a child’s internal “navigator”: they pick up on the pauses, anticipate chord changes, and exercise their thinking even while relaxing.

Cognitive and physiological parameter	Synthetic music (Mass-market content)	Live acoustic music (Therapeutic)
Nature of sound production	Electronic oscillators, MIDI files	Physical resonance of materials (wood, metal, strings)
Acoustic dynamics	Maximum compression, continuous noise	Natural volume fluctuations, presence of pauses ("Ma" principle)
Prediction Error (Predictive Coding)	Absent (rhythm is quantized, fully predictable)	Optimal (natural agogics, micro-rhythmic shifts)
Impact on HPA axis	Hyperstimulation, increased cortisol levels	Suppression of sympathetic activity, decreased cortisol
Impact on attention	Dopamine depletion, decreased focus	Formation of flow state and deep immersion

Therapeutic Giant:

Scientific Evidence for the Ideal Acoustic Quartet

An understanding of the devastating effects of noise pollution is rooted in a discipline known as soundscape ecology. The founder of this field, Canadian composer and researcher R. Murray Schafer, introduced a fundamental distinction between hi-fi (high-fidelity) and lo-fi (low-fidelity) soundscapes.

In a hi-fi environment, characteristic of the natural world, sounds have a clear signal-to-noise ratio, do not overlap, and create a transparent soundscape. In a lo-fi environment (typical of industrial zones and commercially overloaded audio), broadband masking noise dominates, distorting perspective and depriving the listener of the ability to distinguish subtle details.

Applying the concept of the hi-fi landscape to children’s music explains why the classical acoustic quartet - consisting of a harp, flute, cello, and piano - is the unattainable gold standard for the development and soothing of an infant’s nervous system. In this ensemble, the spectral niches of each instrument do not conflict with one another. They create a crystal-clear soundstage, allowing the developing ear to identify each timbre without stress.

An analysis of the effects of each of the four instruments through the lens of neurobiology reveals their unique therapeutic power:

Harp: Cortisol Tamer and Master of Relaxation

The harp is unquestionably recognized as the “queen of relaxation” in clinical music therapy, especially in neonatology. The harp’s sound-production mechanism (a gentle plucking of the string) provides a smooth acoustic attack and a long, even sustain without sharp percussive peaks that might startle a child.

The effectiveness of live harp music has been confirmed by a series of rigorous randomized controlled trials (RCTs). A study by Schwilling et al. evaluated the effect of live pentatonic harp music on stress levels in preterm infants in an intensive care unit. The infants were exposed to the music for 15 minutes. Analysis of saliva using liquid chromatography-tandem mass spectrometry showed that cortisol levels decreased significantly 25 minutes after the session and remained consistently low even 4 hours later.

Furthermore, harp therapy led to a clinically significant reduction in the number of dangerous episodes of apnea (cessation of breathing), bradycardia (decreased heart rate), and oxygen desaturation. The harp’s vibrations resonate with the body at the micro level, suppressing the activity of the sympathetic nervous system, reducing pain during invasive procedures (such as heel stick blood draws), and creating a deep sense of physiological comfort.

Cello: Safety Frequency and Grounding Effect

While commercial children’s tracks bombard the brain with high frequencies, the cello provides a critically important somatic foundation - low and mid-range frequencies. The spectral and formant range of the cello is remarkably close to the frequency characteristics of the human voice (specifically, a male baritone or a low female contralto).

Infants are evolutionarily programmed to prioritize the detection of human voice patterns, as the human voice is the primary marker of an adult’s presence and, consequently, of survival. The sound of the cello, thanks to the legato bowing technique, possesses a sustained, flowing quality that physiologically prompts the listener to slow their internal rhythm, lower their shoulders, and take deeper breaths. Low frequencies do not require an immediate physiological response from the body. The cello does not exaggerate emotions but offers a deep, velvety timbre that creates a “grounding” effect. This instrument conveys absolute confidence to the child, allowing the overactive amygdala to switch off its alert mode and prepare the body for sleep.

Flute: Acoustic Imitation of Breathing

In a therapeutic quartet, the flute serves as a link to nature and helps regulate breathing patterns. Sound production on woodwind instruments depends directly on human exhalation. This means that the flute’s musical phrases are physically limited by the musician’s lung capacity. This limitation creates organic, natural pauses in the melody, causing the entire acoustic fabric to “breathe.”

Infants possess a powerful innate predisposition (mediated by the mirror neuron system) to unconsciously synchronize with the breathing patterns they perceive from the outside. The flute’s classical, rounded sound is completely devoid of the harsh mechanical overtones characteristic of cheap synthesizers. In the deep subcortical structures, it is strongly associated with beneficial natural phenomena (birdsong, the sound of wind in the leaves), which fits perfectly into the concept of a healthy acoustic environment. When integrated into a quartet, the flute acts as a gentle stimulator of attention, sustaining the child’s interest by gently shifting the brain’s focus without causing sensory overload.

Piano: Architecture, Structure, and Predictability

The function of the grand piano (or acoustic piano) in this ensemble is to provide a harmonic foundation and spatial structure. The piano has an enormous range and the ability to establish a clear, multi-layered harmonic progression.

As previously noted in the context of predictive coding, a child’s brain desperately needs a structured environment to minimize entropy and reduce uncertainty. If the acoustic or visual environment is too chaotic, stress arises. The piano’s chordal foundation creates a comprehensible, mathematically precise acoustic landscape. The predictable resolution of musical intervals and chord progressions acts on a child’s psyche as powerful neurobiological confirmation that “the system is stable; the rules of this world work”. Furthermore, a live piano generates an extremely complex network of harmonic overtones that is physically impossible to fully replicate with digital instruments. It is precisely the perception of these subtle natural overtones that is critically important for the development of spatial hearing and phonemic sensitivity, which are necessary for the successful acquisition of speech in the future.

A recipe for an evening ritual: Feel free to ditch those plastic electronic gadgets. Play high-quality recordings of live instruments with a calm tempo (about 60 beats per minute - in time with a mother’s calm heartbeat). The micro-vibrations of harp strings or the velvety timbre of a cello physically ground the child and shift their nervous system into a state of deep recovery.

Listen to our TinyBots' soundtrack: TinyBots, Season 1 (Original Soundtrack) TinyBots, Season 1 (Instrumental)

Structural Changes in Neural Networks Under the Influence of High-Quality Music

The impact of live, acoustic music on infants is not limited to momentary relaxation. Cutting-edge neuroimaging studies demonstrate that appropriate musical stimulation literally reshapes the physical architecture of a child’s brain.

A group of scientists led by Lordier conducted a groundbreaking study using resting-state functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) at clinics in Geneva and Lausanne. The researchers compared the brain development of premature infants, some of whom listened to specially composed music (featuring a harp and bells) while in the intensive care unit, while others remained in standard hospital settings.

The scan results, obtained at an age equivalent to that of a full-term infant (TEA), demonstrated that the musical intervention led to a statistically significant strengthening of functional connections within key cerebral networks. In particular, children who listened to music showed a marked strengthening of the connection between the salience network - which is responsible for integrating sensory information and emotions - and higher-order cognitive, auditory, and sensorimotor cortical networks. DTI metrics also revealed improved structural maturation of white matter (fractional anisotropy) in the acoustic radiations and external capsules of the brain. This irrefutably proves that acoustically correct music serves as a powerful catalyst for the maturation of neural pathways responsible for emotional control and information processing, making the brain architecture of vulnerable children similar to that of healthy full-term infants.

Neurobiological conclusion

Exposing the modern commercial industry of children’s audio content is not a manifestation of aesthetic snobbery, but a strict demand for basic neurobiological and physiological safety. The widespread use of high-frequency, heavily compressed, synthetic sounds under the guise of “fun educational songs” or “lullabies” causes proven, documented harm to infants’ endocrine systems and the architecture of their central nervous systems. Such content inevitably causes sensory overload, depletion of executive functions, dysregulation of the HPA axis with chronic cortisol release, and disruption of normal sleep phases.

At the same time, live acoustic music, composed in accordance with the principles of neuromusicology and predictive coding, serves as a powerful, non-invasive tool for fostering a healthy psyche. A chamber ensemble consisting of a harp, cello, flute, and piano represents the gold standard of acoustic ecology. With a tempo of 60-70 BPM, the complex micro-rhythms of human performance, and a natural timbre rich in overtones, such a quartet blocks stress responses, activates the parasympathetic nervous system, and stimulates the growth of critically important neural connections in the brain. Replacing toxic “audio fast food” with the transparent vibrations of acoustic strings and the natural breath of the flute is a fundamental investment in the intellect and emotional health of the next generation, protecting them from dopamine traps and sensory chaos.

Sources

1. (PDF) Auditory Development in the Fetus and Infant - ResearchGate, https://www.researchgate.net/publication/223253350_Auditory_Development_in_the_Fetus_and_Infant

2. Developmental programming of auditory learning - jpnim, https://jpnim.com/index.php/jpnim/article/download/010111/1

3. An acoustic gap between the NICU and womb: a potential risk for compromised neuroplasticity of the auditory system in preterm infants - PMC, https://pmc.ncbi.nlm.nih.gov/articles/PMC4256984/

4. Maternal Humming during Kangaroo Care: Effects on Preterm Dyads' Physiological Parameters - PMC, https://pmc.ncbi.nlm.nih.gov/articles/PMC10969544/

5. Music medicine and music therapy in neonatal care: a scoping review of passive music listening research applications and findings on infant development and medical practice - PMC, https://pmc.ncbi.nlm.nih.gov/articles/PMC11664842/

6. The effect of lullaby played to preterm infants in neonatal intensive care units on physiological parameters and pain - PubMed, https://pubmed.ncbi.nlm.nih.gov/39260201/

7. Effect of recorded male lullaby on physiologic response of neonates in NICU - PubMed, https://pubmed.ncbi.nlm.nih.gov/28096005/

8. The Effect of Recorded Mum's Lullaby and Brahm's Lullaby on Oxygen Saturation in Preterm Infants: a Randomized Double-Blind Clinical Trial - PMC, https://pmc.ncbi.nlm.nih.gov/articles/PMC4794548/

9. Effect of lullaby and classical music on physiologic stability of hospitalized preterm infants: a randomized trial - PubMed, https://pubmed.ncbi.nlm.nih.gov/24441085/

10. The effect of listening to lullaby music on physiologic response and weight gain of premature infants - ResearchGate, https://www.researchgate.net/publication/278783437_The_effect_of_listening_to_lullaby_music_on_physiologic_response_and_weight_gain_of_premature_infants

11. TinyBots, uploaded:TinyBots

12. Effect of the sound of the mother's heartbeat combined with white noise on heart rate, weight, and sleep in premature infants: a retrospective comparative cohort study, https://apm.amegroups.org/article/view/107189/html

13. Live Harp Music Reduces Activity and Increases Weight Gain in Stable Premature Infants | Request PDF - ResearchGate, https://www.researchgate.net/publication/23553359_Live_Harp_Music_Reduces_Activity_and_Increases_Weight_Gain_in_Stable_Premature_Infants

14. Is Cocomelon Bad For Kids? Experts Weigh In On The Impact Of Screen Time - Tiny Thinks, https://ourtinythinks.com/insights/is-cocomelon-bad-for-kids-experts-discuss-screen-time-effects/

15. The Algorithm Babysitter: AI-Generated Content and the Emerging Human Rights Crisis in Early Childhood Development, https://www.humanrightsresearch.org/post/the-algorithm-babysitter-ai-generated-content-and-the-emerging-human-rights-crisis-in-early-childho

16. Soundwave's effect on hematic cortisol level: a pilot study - Endocrine Abstracts, https://www.endocrine-abstracts.org/ea/0029/ea0029p56

17. Effect of Musical Stimulation on Placental Programming and Neurodevelopment Outcome of Preterm Infants: A Systematic Review - PMC, https://pmc.ncbi.nlm.nih.gov/articles/PMC9915377/

18. The Loudness War: Background, Speculation and Recommendations - SFX Machine, https://www.sfxmachine.com/docs/loudnesswar/loudness_war.pdf

19. The Loudness War is still ongoing to this day : r/audioengineering - Reddit, https://www.reddit.com/r/audioengineering/comments/1hzo1my/the_loudness_war_is_still_ongoing_to_this_day/

20. Cortisol Reactivity, Maternal Sensitivity, and Learning In Three-Month-Old Infants - PMC, https://pmc.ncbi.nlm.nih.gov/articles/PMC2277326/

21. Mother infant cortisol levels and maternal childhood adversity - PMC - NIH, https://pmc.ncbi.nlm.nih.gov/articles/PMC12749534/

22. Salivary Cortisol Reactivity in Preterm Infants in Neonatal Intensive Care: An Integrative Review - PMC, https://pmc.ncbi.nlm.nih.gov/articles/PMC4809000/

23. How Cortisol Affects Autistic Children: Key Insights - daar, https://blog.daar.com.au/blog/how-cortisol-affects-autistic-children-key-insights

24. 10 Signs Your Baby Is Overstimulated and How to Calm Them - Mustela USA, https://www.mustelausa.com/blogs/mustela-mag/overstimulated-baby

25. Signs of sensory overload | Early Years Educator - MAG Online Library, https://www.magonlinelibrary.com/doi/full/10.12968/eyed.2013.14.12.32

26. How Sensory Overstimulation Can Lead to Unwanted Behaviors - Kids Included Together, https://www.kit.org/blog/how-sensory-overstimulation-can-lead-to-unwanted-behaviors/

27. The Immediate Impact of Different Types of Television on Young Children's Executive Function - PMC, https://pmc.ncbi.nlm.nih.gov/articles/PMC9923845/

28. Does exposure to fast-paced television reduce cognitive function in young children? - The Sedentary Behaviour Research Network (SBRN), https://www.sedentarybehaviour.org/2011/10/25/does-exposure-to-fast-paced-television-reduce-cognitive-function-in-young-children/

29. ‪Angeline LIllard‬ - ‪Google Scholar‬, https://scholar.google.fr/citations?user=eKwZBZ8AAAAJ&hl=fr

30. Predictive coding - Wikipedia, https://en.wikipedia.org/wiki/Predictive_coding

31. Beyond the Adult Mind: A Developmental Framework for Predictive Processing in Infancy - Repositori UPF, https://repositori.upf.edu/bitstreams/f664e529-3602-45b7-b642-1e8b14e97b10/download

32. Predictive coding and attention in developmental cognitive neuroscience and perspectives for neurodevelopmental disorders - PMC, https://pmc.ncbi.nlm.nih.gov/articles/PMC11795830/

33. Human newborns form musical predictions based on rhythmic but not melodic structure, https://www.biorxiv.org/content/10.1101/2025.02.19.639016v1.full-text

34. Human newborns form musical predictions based on rhythmic but not melodic structure - Research journals - PLOS, https://journals.plos.org/plosbiology/article/file?id=10.1371/journal.pbio.3003600&type=printable

35. The relation between rhythm processing and cognitive abilities during child development: The role of prediction - Frontiers, https://www.frontiersin.org/journals/psychology/articles/10.3389/fpsyg.2022.920513/full

36. Acoustic Ecology and the Soundscape Bibliography - | Leonardo/ISAST, https://leonardo.info/isast/spec.projects/acousticecologybib.html

37. Introduction to Acoustic Ecology | PDF | Sound | Classical Mechanics - Scribd, https://www.scribd.com/document/554833343/An-Introduction-To-Acoustic-Ecology-by-Kendall-Wrightson

38. Acoustic Ecologists and Environmental Psychologists: Working Toward a Quieter and Healthier Soundscape, https://journals.lib.sfu.ca/index.php/aer/article/download/6097/5367/20648

39. Sounding Out Normative and Colour-Blind Listening in Acoustic Ecology, https://cjc.utppublishing.com/doi/10.3138/cjc.2022-0025

40. Live music reduces stress levels in very low-birthweight infants - PubMed, https://pubmed.ncbi.nlm.nih.gov/25545416/

41. Clinical observations of live improvisational harp music in neonatal intensive care, https://mmd.iammonline.com/index.php/musmed/article/download/497/pdf/1560

42. The Effect of Live Spontaneous Harp Music on Patients in the Intensive Care Unit - PMC, https://pmc.ncbi.nlm.nih.gov/articles/PMC3863466/

43. Why the cello feels like the sound of human emotion - FODMAP Everyday, https://www.fodmapeveryday.com/why-the-cello-feels-like-the-sound-of-human-emotion/

44. Auditory and Music Development, https://trainorlab.mcmaster.ca/research/Infant%20and%20Child%20Auditory%20Development

45. Music in the brain - Centre for Eudaimonia and Human Flourishing, https://www.kringelbach.org/papers/nrn_VuustKringelbach2022.pdf

46. Music enhances structural maturation of emotional processing neural pathways in very preterm infants - PubMed, https://pubmed.ncbi.nlm.nih.gov/31765804/

47. Music enhances structural maturation of emotional processing neural pathways in very preterm infants, https://cibm.ch/wp-content/uploads/1-s2.0-S1053811919309826-main.pdf

48. Music in premature infants enhances high-level cognitive brain networks | PNAS, https://www.pnas.org/doi/abs/10.1073/pnas.1817536116

49. Music in premature infants enhances high-level cognitive brain networks - MIP:Lab, https://miplab.epfl.ch/pub/lordier1902.pdf

50. Longitudinal functional brain connectivity maturation in premature newborn infants: Modulatory influence of early music enrichment - PubMed, https://pubmed.ncbi.nlm.nih.gov/40041298/