What does directivity mean?
Directivity is a technical noun describing how strongly a device concentrates sound or electromagnetic energy in particular directions instead of spreading it evenly in all directions. It appears chiefly in two fields: in acoustics, it characterizes loudspeakers and microphones, explaining why a cardioid microphone captures a singer clearly while rejecting crowd noise behind it; in antenna engineering, it measures how well an antenna focuses transmitted or received power toward a chosen direction, usually compared against a theoretical isotropic radiator and expressed in decibels. High directivity means sharp focusing and greater reach or selectivity; low directivity means broad, even coverage. The term derives ultimately from the Latin dirigere, "to direct," via the adjective "directive." Because it is precise and quantitative, directivity is indispensable in engineering literature but seldom heard outside specialist contexts, where words like "focus" or "directionality" serve as looser everyday substitutes.
nounThe degree to which a device, such as an antenna, loudspeaker, or microphone, concentrates its transmission or reception of sound or electromagnetic waves in particular directions rather than uniformly in all directions.
- In acoustics and audio engineering, the extent to which a loudspeaker or microphone emits or picks up sound predominantly in certain directions rather than equally in all directions.
- In antenna theory and electromagnetics, the ratio of the radiation intensity of an antenna in a given direction to that which would be produced by an ideal isotropic radiator radiating the same total power.
"The parabolic antenna's high directivity allowed it to focus the signal on a single satellite."
"The cardioid microphone's directivity makes it ideal for isolating a vocalist on a noisy stage."
"Engineers improved the antenna array by adjusting element spacing to maximize directivity toward the horizon."
Rarely pluralized; the singular is normally used even when discussing multiple devices.
"The report compared the directivities of several microphone patterns."
A satellite dish is essentially a giant mirror for radio waves — its directivity is what lets it hear one spacecraft whispering from billions of miles away while ignoring everything else in the sky.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of directivity
"Directivity" was formed in the nineteenth century by combining the adjective "directive," meaning serving to direct or guide, with the noun-forming suffix "-ity." Both trace back through Latin directivus and directus, the past participle of dirigere, "to straighten or aim," itself formed from dis- ("apart") + regere ("to rule or make straight"). The word entered English scientific vocabulary as engineers needed a precise term for directional concentration of radiation, alongside cognates such as "direction," "director," and "erect."
Related word forms
How directivity is actually used
"Directivity" is a technical term used almost exclusively in engineering and scientific contexts — acoustics, audio engineering, and antenna design — and is rare in everyday speech. It is typically discussed quantitatively, often as high or low directivity, or expressed in decibels.
Easily confused with directivity
"Directness" refers to straightforwardness or lack of ambiguity in speech or action, while "directivity" is a technical measure of how strongly a physical device radiates or receives energy in specific directions.