"became audible" is correct and usable in written English.
You can use it to describe a sound that can be heard. For example: "The crunching of the leaves under the footsteps became audible as he walked closer."
For the first time, in the months that followed, my parents' conflicts became audible.
So she was awake just after 4 a.m., when the sound of screaming became audible.
"But last fall, it became audible across the country," he said.
However, when it became quickly apparent that he wasn't much of a swimmer, laughter became audible above the half-hearted cheers of the bemused crowd.
Abetted by loudspeakers farther back, the orchestra sounded clear and bright (and the harpsichord became audible), but the singers, not as prominently amplified, took on a corona of resonance.
Many of those followers were visible among the 15,000 in situ at Caesar's Palace and they soon became audible as Michael Buffer handed the microphone to McGuigan's father.
Antiphonal volleys of snoring become audible.
If two whistles are blown at the same time the sound becomes audible.
No one on the platform speaks when the first circling B-29s become audible and sometimes briefly visible overhead.
Too low a bit-rate used for compression and artifacts not present in the original recording can become audible in the reproduction.
He then hits a gray "speak" button and the typed text becomes audible, the words accentuated by his facial expressions and laughter.
