croon

低吟、轻声唱、哼唱

He crooned an old love song while washing the dishes.

他一边洗碗，一边低吟一首老情歌。

低声说、轻声细语

She crooned a few soothing words to the frightened child.

她对受惊的孩子轻声说了几句安抚的话。

低吟、轻哼

His voice dropped to a soft croon near the end of the song.

歌曲快结束时，他的声音转为柔和的低吟。