1 Corinthians 14:8

For if the trumpet give an uncertain voice, who shall prepare himself for war?

'uncertain voice' -'an indistinct sound' (NASV) 'There were sound patterns made on the trumpet which called people to arise and fight. What if the trumpeter blew without making any recognizable pattern? Would the people know to rise to battle? Well, that's how foreign languages sound to the native. He gain nothing because he doesn't know what is being said.' (McGuiggan p. 180)

In this case, an unclear trumpet blast, might result in defeat and lives lost unnecessarily. The abuse of the tongues in the assembly, had definitely resulted in. failure to spiritually build up other Christians. Edification had been lost!