This root form (lemma) is used in 3 different forms in the NT: ἤχους (GNS), ἤχῳ (DMS), ἦχος (NMS).
It is glossed in 4 different ways: ‘a sound’, ‘the report’, ‘of the sound’, ‘to the sound’.
OET LUKE 4:37 Greek word=ἦχος (aʸⱪos) Morphology=NMS English gloss=‘the report’ SR GNT LUKE 4:37 word 6
OET LUKE 21:25 Greek word=ἤχους (aʸⱪous) Morphology=GNS English gloss=‘of the sound’ SR GNT LUKE 21:25 word 23
OET ACTS 2:2 Greek word=ἦχος (aʸⱪos) Morphology=NMS English gloss=‘a sound’ SR GNT ACTS 2:2 word 8
OET HEB 12:19 Greek word=ἤχῳ (aʸⱪōi) Morphology=DMS English gloss=‘to the sound’ SR GNT HEB 12:19 word 3