Keening

The keening whistle of the tea kettle signaled that the water had boiled.

The keening whistle of the teapot signaled that the water was boiling.

The lonely lighthouse emitted a keening beam of light that swept across the dark sea.

The old television emitted a high-pitched keening noise whenever it was turned on.

The chilling keening of the banshee sent shivers down the spines of those who heard it.