Along with "emerge", you could use "arise"
a : to begin to occur or to exist : to come into being or to attention
Emerged is taking over in usage, though, vs. arose, when paired with "sound"
You might try looking up the comparison for your specific example.
To clarify the difference between verbs that reference the production or perception of a sound or image:
Like appear (and emerge), arise references the perception of its subject (to come in sight, to come into attention, to become known).
Appear, 1 a : to be or come in sight
when the sun appears on the horizon
Compare to the verb sound, which references the moment of sound production
transitive verb 1 a : to cause to sound
sound a trumpet
intransitive verb 1 a: to make a sound