A bronze age word linked to rich noisy sounds like the crash of metal or the sound of crowds and insects. I like to imagine a parallel intention between their linking of the natural and man made and our own somewhat attenuated usage.
Then Cycnus, eager to kill the son of almighty Zeus, struck upon his shield with a brazen spear but did not break the bronze; and the gift of the god saved his foe. But the son of Amphitryon, mighty Heracles, with his long spear struck Cycnus violently in the neck beneath the chin, where it was unguarded between helm and shield. And the deadly spear cut through the two sinews; for the hero's full strength lighted on his foe. And Cycnus fell as an oak falls or alofty pine that is stricken by the lurid thunderbolt of Zeus; even so he fell, and his armor adorned with bronze clash about him.
êchô [like earlier êchê,] 1. a sound, but properly of a returned sound, echo, Hhymn., Hes., etc. 2. generally, a ringing sound, Soph., Trag.; tên Boiôtiên kateiche êchô hôs . . Boeotia rang with the news that . . , Hdt.
êchê (Wêchê): resounding, echoing noise, roar; of voices (compared to the waves), wind , Il. 2.209, Il. 16.769; freq. êchêi thespesiêi, Od. 3.150.
êch-ê , Dor. acha , hê, sound, noise, ê. amphoterôn (sc. Argeiôn kai Trôôn) hiket' aithera Il.13.837 : freq. in dat., êchêi, hôs hote kuma . . bremetai 2.209 ; of trees, pros allêlas ebalon tanuêkeas ozous êchêi thespesiêi 16.769 ; petrê . . hê de te êchêi erchetai emmemauia Hes.Sc.438 ; in Trag., cry of sorrow, wail, E.Med.149 (lyr.), Hipp.585 (lyr.), cf. Nic.Al.304; but also salpingos ê. E.Ph.1378; en emoi hê ê. tôn logôn bombei Pl.Cri.54d , cf. Ti. 37b; of the grasshopper, Longus 1.23: rarely of articulate sounds, E.Ph.1148, Opp.C.1.23; rumour, talk, Plu.Cat.Ma.22. (Perh. fr. swa¯gˆh-, cf. iacheô, OE. swógan 'resound', Engl. sough.)
êchê a sound or noise of any sort, Hom., attic; of the confused noise of a crowd, the roar of the sea, the groaning of trees in a wind, Il., etc.:--in Trag., like iachê, a cry of sorrow, wail; but, salpingos êchê Eur.:--rarely of articulate sounds, id=Eur.