Stentor

Stentor was a proverbial herald of the Greeks at Troy, whose voice was said to be equal to that of fifty men. The modern English word 'stentorian', meaning 'extra loud' (of a voice), comes from his name, which in turn derives from some Indo-European root such as ston- or sten- denoting a loud voice (compare Greek steno, 'to groan', Latin tonare, 'to thunder', Russian ston, 'groan', etc.).

There may also be an influence of Greek tonos, 'stretching', 'straining of the voice', which word is reflected in English 'tone'.