Music and the Brain: Comprehensive Course Review

Comprehensive vocabulary flashcards covering the acoustics, psychoacoustics, rhythm, entrainment, and cognitive neuroscience of music across Lectures 1 through 3.

Entrainment

A physical and psychological process where two independent rhythmic systems or processes interact, adjust, and eventually synchronize or 'lock in' to a common phase and/or periodicity.

Mousike

An Ancient Greek concept denoting the inseparable union of song, dance, and the spoken word.

Tempo

The rate or speed at which musical events unfold over time, typically quantified in beats per minute ($\text{bpm}$) and generally ranging between $40\,\text{bpm}$ and $180\,\text{bpm}$.

Tactus

The natural, spontaneous motor rate at which a listener taps their foot or moves in synchronization with the musical beat, which dissociates from the nominal tempo.

Rhythm

The perceived temporal organization of a serial pattern of durations (notes and rests) determined primarily by note onsets rather than total duration.

Beat

A steady, isochronous (regularly spaced) acoustic pulse perceived in music that creates an underlying framework of temporal expectations.

Meter

The cyclical, hierarchical grouping of beats into regular units defined by alternating strong and weak accents.

Psychological Present

The perceptual temporal integration window ranging between $0.1\,\text{s}$ ($100\,\text{ms}$) and $2.5\,\text{s}$ ($2500\,\text{ms}$), linked directly to working memory capacity.

Spontaneous Motor Tempo (SMT)

An individual's preferred, unprompted rate of rhythmic tapping (typically measured around $100 - 120\,\text{bpm}$ in adults and around $150\,\text{bpm}$ in young children).

Beat Deafness

A specific form of congenital amusia characterized by a selective inability to perceive, track, or synchronize motor movements to an external musical beat, occurring in approximately $50\%$ of amusics.

Interpersonal Entrainment

The temporal and spatial motor coordination and phase synchronization that occurs between two or more interacting individuals during music-making or dancing.

Self-Entrainment

The internal biological synchronization between two or more oscillatory systems within a single organism, such as the coupling of respiration patterns and cardiac rhythms.

Neural Entrainment

The phase-locking of endogenous electrical oscillations in the brain (such as delta, theta, alpha, beta, and gamma bands) to the periodic structure or beat of an auditory stimulus.

Auditory-Motor Brain Coupling

Functional connectivity between auditory cortex regions and motor control structures (supplementary motor area, premotor cortex, putamen, and cerebellum) that activates during rhythm perception even in the complete absence of physical movement.

Phrenology

An early psychological doctrine founded by Franz Joseph Gall ($1758 - 1828$) proposing that localized mental faculties, including music as one of $27$ mental faculties, correspond to skull topography.

Electroencephalography (EEG)

A neuroimaging method recording electrical brain activity from the scalp, first performed in humans in $1924$ by Hans Berger.

Acoustics

The scientific discipline derived from the Greek akoúein ('to hear') that studies the production, propagation, transmission, and reception of mechanical sound waves.

Sound

A mechanical disturbance created by an event acting upon an object that produces alternating pressure variations propagating through an elastic medium.

Sound Pressure Level (SPL)

A logarithmic measure of the effective pressure of a sound wave relative to the human auditory threshold of $2 \times 10^{-5}\,\text{Pa}$, expressed in decibels ($\text{dB}$).

Longitudinal Wave

A wave in which the particles of the propagating medium oscillate parallel to the trajectory of wave travel, creating alternating compressions and rarefactions.

Transverse Wave

A wave in which particle displacement within an elastic medium occurs perpendicular to the direction of propagation.

Phase

The fractional progression of a periodic sound wave relative to a reference point or another wave, expressed in degrees from $0^\circ$ to $360^\circ$, where $180^\circ$ difference causes destructive cancellation.

Reverberation Time ($RT_{60}$)

The duration of time required for acoustic energy in an enclosed architectural space to decrease by $60\,\text{dB}$ after the sound source has ceased.

Porous Absorber

Architectural acoustic material (such as carpets, drapes, and plush seat upholstery) that captures sound energy through viscous thermal loss, attenuating high frequencies more efficiently than low frequencies.

Resonant Absorber

Acoustic materials (such as flexible wood panels) that resonate at specific natural mechanical frequencies to dissipate low-frequency (bass) energy.

Auditory Transduction

The biological process in the inner ear where mechanical fluid oscillations are converted into electrical neurochemical signals via deflection of stereocilia on hair cells.

Basilar Membrane

A tapered, elastic anatomical structure within the cochlea that performs mechanical frequency analysis through tonotopic spatial organization.

Organ of Corti

The biological receptor organ seated on the basilar membrane containing $16{,}000 - 20{,}000$ sensory hair cells with cilia that release neurotransmitters into the auditory nerve.

Tinnitus

The psychoacoustic perception of phantom ringing, buzzing, or hissing sounds caused by neural hyperactivity or hair cell damage in the cochlea, affecting $10 - 15\%$ of the population.

Auditory Scene Analysis (ASA)

A theoretical framework formulated by Albert S. Bregman detailing how the human auditory system decomposes complex acoustic mixtures into discrete, coherent sound streams.

Auditory Stream

An internal perceptual representation of a coherent sequence of acoustic events perceived as emanating from a single environmental source over time.

Gestalt Psychology

An early 20th-century psychological movement established by Max Wertheimer, Wolfgang Köhler, and Kurt Koffka postulating that perceptual experience is structured into organized, holistic forms rather than mere sums of elementary parts.

Phi Phenomenon

An apparent motion illusion identified in $1912$ by Max Wertheimer where two stationary visual stimuli flashed in rapid succession are perceived as a single entity moving smoothly across space.

Law of Prägnanz (Good Figure)

A fundamental Gestalt grouping principle stating that sensory patterns are automatically organized and perceived in the simplest, most regular, and most stable form possible.

Multi-Stability

A perceptual phenomenon where ambiguous sensory inputs spontaneously alternate back and forth between two or more mutually exclusive, stable interpretations.

Streaming by Pitch Proximity

An auditory scene analysis mechanism where a rapid sequence of tones alternating across two widely separated frequency registers segregates into two parallel, simultaneous perceptual streams.

Melodic Contour

The holistic spatial shape formed by the direction of pitch changes (rising, falling, or remaining level) in a melody across time, independent of exact musical intervals.

Threshold of Hearing

The quietest intensity of sound that a healthy human ear can perceive, standardized as $0\,\text{dB}\,\text{SPL}$ ($10^{-12}\,\text{W/m}^2$ or $2 \times 10^{-5}\,\text{Pa}$).

Threshold of Pain

The acoustic intensity level at which sound waves induce physical discomfort and auditory damage in human ears, typically established at $130\,\text{dB}\,\text{SPL}$.

Loudness War

The multi-decade trend in audio mastering of applying excessive dynamic range compression to recorded music to maximize overall playback loudness at the expense of fidelity.

Root Mean Square (RMS) Energy

A statistical calculation representing the continuous effective magnitude or average perceived loudness of an audio waveform over time.

Fundamental Frequency ($F_0$)

The lowest frequency component of a periodic complex waveform, representing the physical repetition rate of the entire wave and determining its perceived pitch.

Harmonic Series

A mathematical set of acoustic frequencies that are positive integer multiples ($n \times F_0$) of the fundamental frequency.

Fourier Analysis

A mathematical algorithm that breaks down any complex periodic waveform into its constituent pure sinusoidal frequencies, relative amplitudes, and phases.

Missing Fundamental Phenomenon

A psychoacoustic effect where the auditory system infers and perceives the pitch corresponding to $F_0$ from higher harmonic overtones even when the fundamental frequency itself is physically filtered out.

Congenital Amusia

A neurodevelopmental disorder present from birth affecting roughly $4\%$ of the population, characterized by severe deficits in fine pitch discrimination and melody recognition despite normal hearing and intellect.

Acoustic Beating

Periodic fluctuations in perceived loudness occurring when two sinusoidal sound waves differing in frequency by approximately $\le 15\,\text{Hz}$ interfere constructively and destructively.

Roughness

A sensory buzzing or harsh psychoacoustic sensation perceived when two interacting frequency components differ by more than $15\,\text{Hz}$ but fall within the same critical bandwidth of the basilar membrane.

Consonance

The subjective acoustic quality of pleasantness, stability, or smoothness produced by musical intervals whose partials align cleanly with minimal basilar membrane critical band roughness.

Dissonance

The subjective acoustic quality of tension, roughness, or instability generated when frequency components of an interval fall within a critical band, producing rapid sensory beats.

Absolute Pitch (AP)

The rare cognitive ability (prevalent in approximately $1$ in $10{,}000$ individuals) to identify or produce a specific musical note without any reference pitch.

Timbre

The multidimensional perceptual attribute of auditory sensation that allows a listener to distinguish two sounds that share identical pitch, loudness, and duration.

ADSR Envelope

The temporal amplitude profile of an acoustic or synthesized musical sound, divided into four sequential stages: Attack, Decay, Sustain, and Release.

Spectrogram

A visual acoustic representation that depicts the distribution of sound pressure level across different frequency bands as a function of time.