perceptible

“Her voice was barely perceptible over the noise, but her gestures made her meaning clear.”

“Sunning himself on the board steps, I saw for the first time Mr. Farquhar Fenelon Cooke.[…]A silver snaffle on a heavy leather watch guard which connected the pockets of his corduroy waistcoat, together with a huge gold stirrup in his Ascot tie, sufficiently proclaimed his tastes.[…]But withal there was a perceptible acumen about the man which was puzzling in the extreme.”