a sound that reaches the ear: most often a voice, but also any noise a thing makes, and the words a voice carries.
At its core this is the word for a sound that reaches a hearer. Its center of gravity is the voice, the sound a living being makes when it speaks, sings, weeps, or calls out, whether that being is a person or God. But the same word stretches naturally to cover any noise at all: thunder, a trumpet, marching feet, rushing water, the roar of a city, even the rustle of a leaf. Hebrew does not split voice and sound into two words the way English does, so one word does the work of both, and the context tells you which is meant.
Because a voice carries words, the word also slides from the sound itself to what the sound says. So it can mean a report, a proclamation, or a public summons, the message the voice delivers rather than its bare noise.
Two fixed expressions grow out of this. To lift up the voice is to break out loud, almost always in weeping or in a great shout. And to listen to the voice of someone, above all God, is the ordinary Hebrew way of saying to obey: the faithful person heeds what the voice says, while the rebel is the one who will not listen to it. These are shades of one idea, not separate words. A reader can move from God's voice at Sinai, to the sound of the trumpet there, to the people's pledge to heed that voice, without ever leaving the same Hebrew word.