| 摘要 |
PURPOSE:To extract a pitch from an input acoustic signal, and enable the tempo of the input acoustic signal to be detected on the basis of the pitch extraction result. CONSTITUTION:An input acoustic signal is subjected to a digital filtering process via a digital signal processing means 44, and the envelope value of a frequency spectrum corresponding to each scale is detected. A scale detection means 44 detects a scale sound contained in the acoustic signal on the basis of the detected envelope value. The generation cycle of the detected scale sound from the predetermined position of an envelope curve to another predetermined position is detected by a cycle detection means 2, and a tempo detection means 2 detects a tempo on the basis of the detected generation cycle and a rhythm entered from a rhythm specifying means 6. The detected tempo is outputted by a tempo outputting means 7. |
