Irsele los gallos (voz), emitir una nota falsa y chillona al cantar, perorar o hablar.

To get a crack, to get a crack in one's voice, one's voice cracks.

"Her voice cracked with emotion as she told the story."
Cambridge Dictionary Online

On Websites:

"How to avoid getting cracks in your voice when singing."
WikiHow


In News:

"Vulnicura may not be Björk’s best album, and this was not her finest concert. Her voice cracked on the highest note of The Pleasure is All Mine; s"
The Guardian