infrasound
C2Technical / Scientific
Definition
Meaning
Sound waves with frequencies below the lower limit of human hearing (approximately 20 hertz).
Low-frequency acoustic energy that, while inaudible, can be physically perceived through vibration or resonance and is studied in geophysics, engineering, and animal communication.
Linguistics
Semantic Notes
Term is specific to acoustics, physics, and biology. Often contrasted with 'ultrasound' (frequencies above human hearing). It is a mass noun.
Dialectal Variation
British vs American Usage
Differences
No significant lexical differences; term is identical in spelling and meaning. Pronunciations differ slightly.
Connotations
Neutral technical term in both varieties.
Frequency
Equally low-frequency in both dialects, confined to specialist contexts.
Vocabulary
Collocations
Grammar
Valency Patterns
N/A (primarily a noun). The verb form is rarely used.Vocabulary
Synonyms
Strong
Neutral
Weak
Vocabulary
Antonyms
Phrases
Idioms & Phrases
- “N/A”
Usage
Context Usage
Business
Rare, except in industries related to seismic monitoring or specialised acoustics.
Academic
Common in physics, geophysics, acoustics, and zoology papers.
Everyday
Virtually never used in casual conversation.
Technical
Primary context: used precisely to describe a specific range of acoustic phenomena.
Examples
By Part of Speech
verb
British English
- The equipment is used to infrasound the area for geological faults.
- Researchers attempted to infrasound the chamber.
American English
- The system can infrasound the perimeter for seismic activity.
- They plan to infrasound the structure for resonance.
adverb
British English
- The device records infrasonically.
- The signal was transmitted infrasonically.
American English
- The array listens infrasonically for explosions.
- The animals communicate infrasonically.
adjective
British English
- Infrasound waves are produced by earthquakes.
- They set up an infrasound detection array.
American English
- Infrasound monitoring stations are deployed globally.
- The volcano emits infrasound signals.
Examples
By CEFR Level
- Some animals can sense infrasound.
- Infrasound is sound that humans cannot hear.
- Geophysicists use infrasound to monitor volcanic activity.
- The study focused on how elephants use infrasound for long-distance communication.
- Advances in infrasound detection have improved early warning systems for tsunamis.
Learning
Memory Aids
Mnemonic
Think: 'INFRAstructure' is below ground; 'INFRAsound' is below the audible range of sound.
Conceptual Metaphor
SOUND WAVES ARE A SPECTRUM (with infrasound at the low, inaudible end).
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Do not confuse with 'инфразвук' (direct equivalent, correct).
- Avoid calquing as 'under-sound' or 'sub-sound'.
- Not synonymous with 'глухой звук' (muffled/deaf sound), which refers to quality, not frequency.
Common Mistakes
- Using 'infrasound' to mean 'very quiet sound' (it's about frequency, not volume).
- Treating it as a countable noun (e.g., 'an infrasound' is incorrect).
- Confusing spelling with 'infrasonic' (the adjective).
Practice
Quiz
What is the primary characteristic of infrasound?
FAQ
Frequently Asked Questions
Yes, while inaudible, high-intensity infrasound can be perceived as vibrations or pressure in the chest and ears, sometimes causing discomfort.
Earthquakes, volcanic eruptions, ocean waves, thunderstorms, and some large animals like elephants and whales.
At very high intensities, prolonged exposure may cause nausea, dizziness, or anxiety, but typical environmental levels are not considered harmful.
Using specialised microphones called infrasonic sensors or microbarometers, which are sensitive to very low-frequency pressure changes in the air.