The crossword solution for the term 'unchanging intonation' is 'DRONE'. A DRONE is a sound that is sustained and continuous, without any variation in pitch or volume. It is often used to describe a monotonous, repetitive sound, such as the sound of a bee buzzing or a motor running. In music, a DRONE is a sustained note or chord that provides a harmonic foundation for the melody. In speech, a DRONE is an unchanging intonation that is used to emphasize a point or to create a sense of calm.