infrasound C2+ Topic:Science & Research Also spelled infra-sound US /ˈɪnfrəˌsaʊnd/ UK /ˈɪnfrəˌsaʊnd/ See IPA manual Freq #78000 Meanings 1 noun sound waves having a frequency below the human audible range (below about 20 Hz). "Was it infra-sound? Thesaurus ↔ Opposites ultrasound Etymology Formed from infra- ("below") + sound, referring to frequencies below the lower limit of ordinary human hearing. Topics Science & Research External links Cambridge Dictionary Wiktionary Google Images # infrasound **Type:** Word **Level:** C2+ **Part of speech:** noun **IPA (US):** /ˈɪnfrəˌsaʊnd/ **IPA (UK):** /ˈɪnfrəˌsaʊnd/ **Frequency rank:** 78000 ## Meanings 1. sound waves having a frequency below the human audible range (below about 20 Hz). ## Examples - "Was it infra-sound? ## Antonyms - ultrasound ## Etymology Formed from infra- ("below") + sound, referring to frequencies below the lower limit of ordinary human hearing. ## Topics - Science & Research markdown