#acoustic

• To soundproof — To apply a layer of soundproofing compound, bituminous mastic, or other acoustic insulating material onto a surface (especially on a vehicle chassis or structural construction components) in order to reduce noise, damp acoustic vibrations, and provide anti-corrosive protection.
• Soundproofing — The act of soundproofing and its result; the technical process of applying an acoustic insulating layer, bituminous mastic, or sound-absorbing material onto a surface to diminish noise, damp mechanical vibrations, and provide an effective barrier against corrosion.
• Soundproofed — Covered with a layer of soundproofing compound or acoustic insulating materials to prevent the propagation of noise and vibrations; as a neuter noun, it designates the completed work, result, or process of insonorizing a surface or vehicle.
• Antiphonal — Insulating against noise or damping sound vibrations; pertaining to soundproofing or acoustic reduction. In liturgical or religious music (theology), the term describes a hymnal structure or a mode of vocal performance based on the symmetrical alternation and dialogue between two separate choirs.
• Antiformant — A spectral component of speech sounds (especially nasal, lateral consonants, or attenuated sounds) characterized by a sharp reduction or total absorption of acoustic energy at a specific frequency; an inverse pole in a spectrogram caused by side-branch resonators.
• Anti-rattle — Designed structurally or treated to prevent, reduce, or stop rattling, harsh intermittent friction, or parasitic vibrations in mechanisms in motion. In an industrial sense, it describes a damping device, an elastic gasket, or a lubricating additive structurally engineered to stabilize fine mechanical parts and eliminate acoustic micro-shocks.
• Antinodal — Pertaining to or relating to an antinode (venter); located in the region of maximum amplitude of a standing wave, where the constructive interference of the component waves causes the maximum displacement, oscillation, or variation of a physical parameter (pressure, velocity, electric field).
• Noise-canceling — Isolating, mitigating, absorbing, or canceling noise pollution, parasitic sounds, or unwanted acoustic waves. It applies to insulating materials (sound-absorbing panels, rock wool), highway barriers, engine protective casings, or active electronic technologies (such as ANC headphones) structurally designed to ensure optimal sonic comfort in industrial, urban, or residential environments.
• Anthrophony — The entirety of sounds and noises produced by human activity, technology, and civilization infrastructure within an acoustic soundscape. In modern ecology and bioacoustics, anthrophony is analyzed in contrast with biophony and geophony to measure the degree of noise pollution and its impact on animal behavior and communication.
• Archlute — A historical plucked string instrument that emerged during the Baroque period as an extended variant of the Renaissance lute. Structurally characterized by an elongated neck and a second pegbox designed to accommodate extra open bass strings (diapasons) that were not fretted, it was frequently utilized in Baroque chamber music and orchestras for performing basso continuo accompaniment.
• Arcicembalo — An historical keyboard musical instrument from the harpsichord family, designed in the 16th century by theorist Nicola Vicentino, structurally equipped with multiple keyboards and complex microtonal divisions (up to 31 intervals per octave). This advanced acoustic device was utilized to experiment with ancient Greek musical genres and to achieve just intonation in Renaissance polyphonic music.
• Arciliuto — The Italian nomenclature and international neologism for the archlute, a plucked string instrument developed during the Baroque era. This device structurally combines the traditional lute body with an extended neck supporting two separate pegboxes, allowing the tensioning of extra open bass strings used to sustain the basso continuo in seventeenth and eighteenth-century chamber music ensembles.
• Arciorgano — An historical keyboard musical instrument from the organ family, designed in the 16th century by theorist Nicola Vicentino, structurally equipped with multiple keyboards and a complex system of microtonal pipes adapted to render up to 31 intervals per octave. This experimental acoustic device was used during the Renaissance to explore the chromatic and enharmonic genres of ancient Greek music and to achieve just intonation in academic polyphonic performances.
• Arciviolata — An alternative historical name or extremely rare variant for the instrument known as 'archiviola'; a type of oversized or hybrid viola from the Italian Renaissance period, structurally designed to extend the grave and polyphonic register through the use of experimental keyboard mechanisms or by adding extra sympathetic strings.
• Violin bow — An essential accessory for bowed string musical instruments (violin, viola, cello, double bass), consisting of a thin, slightly curved rod of flexible wood or carbon fiber, between the ends of which a bundle of horsehair is tightly stretched. By rubbing the rosin-treated hairs over the strings, the bow sets them into continuous vibration, generating the sound. In engineering, it denotes a lever or a curved elastic piece used to tension primitive mechanisms.
• Harmonic — Based on harmony, balanced proportion, and structural concordance of elements within an assembly. In physics and acoustics, it describes a periodic oscillatory phenomenon (harmonic motion) or a sinusoidal component (harmonic frequency) of a complex sound, whose frequency is an integral multiple of the fundamental frequency. In mathematics, it refers to means or progressions established according to specific proportions, and in music, it designates the consonant relationship between simultaneously emitted sounds.
• Harmonica — A wind musical instrument consisting of a series of flexible metal reeds mounted inside channels of a wooden or plastic casing, activated by blowing or suction; also, in acoustics, a sinusoidal component of a complex sound whose frequency is an integral multiple of the fundamental frequency, thus defining the specific timbre of an instrument.
• Harmonograph — A mechanical apparatus or device consisting of a system of oscillating pendulums, used to draw and graphically visualize complex geometric curves resulting from the combination of two or more sinusoidal harmonic or vibratory motions.
• Sharpness — The property or quality of being sharp or cutting; the degree of accuracy or thinness of a blade or tip. In a sensory and technical sense, it defines the extreme clarity of an optical image (resolution), the penetration of a mental faculty (intelligence, perspicacity), or the high frequency of a sound (acute pitch).
• Asdic — An acoustic underwater detection apparatus used on naval vessels for the structural localization of submarines, wrecks, or other submerged objects, based on the emission and reception of ultrasonic waves; a precursor system to modern sonar. It also represents a historical acronym derived from the British research committee that developed it during World War I.