| 摘要 |
PURPOSE:To display an actual musical note for its actual length of time by analyzing the height and length of the sound by causing the titled device to determine a continuous sound or discontinuous sound by analyzing an audio signal two times, before and after, within the shortest length of time of the note, and display the note based on the corresponding height and length of the sound. CONSTITUTION:An audio signal passing through an A/D converter 4 is once stored in an RAM7, and then it is analyzed by the operation and high-pitched sound analyzer 8 of a controller 5 two times before and after within the shortest length of a note time through fast Fourier transformation operation, etc. From a frequency corresponding to its power spectrum, high-pitched sound data are determined and stored in the RAM7. Depend on whether the difference of those high-pitched sound data is over or below a threshold value, the input audio signal is judged by a continuous sound detector 9 whether it is continuous sound or not, and a detector 10 for detecting the number of times of analysis and pattern data generates a command signal corresponding to the result of judgement and applies it to a pattern and determining unit 11. Sound length data from the determining unit 11 are sent together with high-pitched sound data from the RAM7 to a CRT14 through a video display processor 12, etc. and notes indicating their pitch and length by the five staff notation are displayed for their actual time on the CRT 14. |
