"increasingly sound" is a correct and usable phrase in written English.
You can use it to describe a situation that is becoming more logical or convincing as time passes. For example, "Our argument is increasingly sound as more evidence is gathered in our favor."
Still, government leaders here increasingly sound as if they are losing confidence.
But this speech was part of a patient strategy that, despite August's rough weather, is looking increasingly sound.
If they are right, the presidential campaign is going to increasingly sound like an out-of-control thread on Reddit.
So why do Beyonce's songs increasingly sound as if the creative process has been turned on its head?
Yet the Brotherhood's explanations are increasingly sound tinged with paranoia and authoritarian arrogance — and the movement has dispatched violent cadres to beat up peaceful opposition protesters.
And as the race enters its final month, campaign officials increasingly sound like executives from retailers like Target and credit card companies like Capital One, both of which extensively use data to model customers' habits.
The closures continued for weeks, and the explanations increasingly sounded like pretexts.
He increasingly sounded wistful notes about the disappearance of the Hollywood he knew in his prime.
Then he and the president will renew a political battle that increasingly sounds more like Labor Day than Memorial Day.
Biden's approach, of promising incremental change and taking the bitterness out of politics, increasingly sounds out of place.
And in recent decades curators and conservators have increasingly sounded the alarm that excessive light destroys valuable art.
