What is a voice?

The empty, hollow reverberation of air passing through vocal chords?

the cry of a baby in the middle of the night
the laughter of a child at play
the tender words of affection from a man to the woman he loves
the pleas of a mother for her sick child
the desperation of a prisoner begging for mercy
the cry of Christ for the forgiveness of those for whom He is dying

What is a voice but the groaning of a heart crying, pleading, reaching out for love.