acoustic shadow
Noise-blocked zone behind
An acoustic shadow is an area where sound waves are blocked or significantly reduced by an obstacle, creating a zone of relative silence.
The phenomenon occurs because sound, like light, travels in waves that can be obstructed by large objects such as hills, buildings, or atmospheric conditions.
The term gained historical significance during Civil War battles, when commanders sometimes couldn't hear nearby fighting due to terrain or weather conditions.
The hill created an acoustic shadow that left the general unaware of the battle raging just two miles away.
Waves spreading past obstacles
- wavefrontSurface of equal phase
- obstacleSomething blocking the way
- barrierObstruction preventing passage
- propagationAct of spreading widely
attenuation · wavelength · interference · reflection · absorption · frequency · amplitude · medium
Lacking in sound
- hushAbsence of sound
- stillnessComplete lack of motion
- soundlessProducing no audible noise
- mutedMade quieter or softer
absence · void · dead zone · pocket · calm · noiseless · faint · imperceptible
Perceiving sound waves
- deafnessLack of auditory function
- inaudibleCannot be heard
- dead spotArea without signal
- earAuditory organ
audiogram · cochlea · audiology · decibel · frequency · pitch · audiometry · hearing loss
Large-caliber battlefield weapons
- battlefieldCombat engagement area
- gunfireDischarge of weapons
- Civil WarCountrymen fighting countrymen
- cannonadeSustained artillery fire
engagement · reconnaissance · flanking · frontline · mortar · volley · Gettysburg · troop movement
Inaudible high-frequency waves
- echocardiographyUltrasound imaging of heart
- imagingProducing visual representations
- sonographyImaging using sound waves
- diagnosticTest to identify problems
lesion · calcification · obstruction · gallstone · kidney stone · artifact · scan · transducer
diffraction
Waves spreading past obstacles
- wavefrontSurface of equal phase
- obstacleSomething blocking the way
- barrierObstruction preventing passage
propagation · attenuation · wavelength · interference · reflection · absorption · frequency · amplitude · medium · sonic
quiet
Lacking in sound
muted · absence · void · dead zone · pocket · calm · noiseless · faint · imperceptible · dampened
hearing
Perceiving sound waves
ear · audiogram · cochlea · audiology · decibel · frequency · pitch · audiometry · hearing loss · muffled
artillery
Large-caliber battlefield weapons
- battlefieldCombat engagement area
- gunfireDischarge of weapons
- Civil WarCountrymen fighting countrymen
cannonade · engagement · reconnaissance · flanking · frontline · mortar · volley · Gettysburg · troop movement · barrage
ultrasound
Inaudible high-frequency waves
- echocardiographyUltrasound imaging of heart
- imagingProducing visual representations
- sonographyImaging using sound waves
diagnostic · lesion · calcification · obstruction · gallstone · kidney stone · artifact · scan · transducer · echo
acoustic, acoustics, acoustical, acoustically, shadow, shadows, shadowy, shadowed, shadowing