1 Corinthians 14:7-9

Young's Literal Translation

⁷ yet the things without life giving sound -- whether pipe or harp -- if a difference in the sounds they may not give, how shall be known that which is piped or that which is harped?

⁸ for if also an uncertain sound a trumpet may give, who shall prepare himself for battle?

⁹ so also ye, if through the tongue, speech easily understood ye may not give -- how shall that which is spoken be known? for ye shall be speaking to air.