Answer: inflect

AnswerCrossword Clue
INFLECTAlter in tone
INFLECTCurve.
INFLECTModulate.
INFLECTVary the pitch of, as the voice
INFLECTModulate
inflectto change the form of (a word) to express grammatical or syntactic relations
inflectto change the pitch of (the voice)
inflectto bend or curve inwards