The king was speaking, his voice sounding flat and tired.
The explosions sounded flat and harsh, not so big as they might have been.
His voice was so charged with emotion that it sounded flat.
His voice sounds flat and ineffectual in the closed space, like something dead at birth.
The words sounded flat and foreign as they came out of my mouth.
In translation, the voice sounded flat and a little scared.
The trouble here is that all enthusiasm tends to be lost and the interview can sound very flat.
He tried to kill you," but seeing the family face in front of him his words sounded flat.
Her voice sounded flat, as if she were far away.
His voice sounded so odd and flat that I got a little scared.