in an undertone, in a low voice
malevolence, ill-will, undertone of hostility
В его голосе звучали насмешливые нотки.
There were mocking undertones in his voice.
В его словах чувствовался странный душок.
There was a strange undertone to his words.
В его голосе звучали сладострастные нотки.
There were lascivious undertones in his voice.
В его голосе слышался странный призвук.
There was a strange undertone in his voice.