Method and apparatus for determining musical notes from sounds
View Patent ↗This method and apparatus extract symbolic high-level musical structure resembling that of a music score. Humming or the like is converted with this invention into a sequence of notes that represent the melody that the user (usually human, but potentially animal) is trying to express. These retrieved notes each contain information such as a pitch, the start time and duration and the series contains the relative order of each note. A possible application of the invention is a music retrieval system whereby humming forms the query to some search engine.
1. A method for detecting the pitch values of notes in a musical sound signal, comprising the steps of:
identifying one or more voiced segments in the sound signal using an energy function of the sound signal;
applying a gradient-based processing to said voiced segments for dividing each voiced segment into one or more notes; and
deriving pitch values of the respective notes in the sound signal.
2. A method according to claim 1 , wherein the process of dividing the voiced segments into notes uses note markers to do so.
3. A method according to claim 2 , wherein the process of deriving the pitch values of the respective notes comprises dividing portions of each voiced segment between the note markers into blocks.
4. A method according to claim 3 , wherein each portion contains the same number of blocks.
5. A method according to claim 1 , wherein the process of deriving the pitch values of the respective notes comprises applying k-mean clustering on pitch values derived for the blocks between the note markers.
6. A method according to claim 1 , further comprising the step of rounding the derived pitch values of the respective notes to the nearest note values.
7. A method according to claim 1 , wherein the identifying of the voiced segments is performed based on a determination of silences in the sound signal.
8. A method according to claim 1 , further comprising the step of extracting notes from said pitch values to create note descriptors.
9. A method according to claim 1 , wherein the sound signal is digitized.
10. A method according to claim 1 , wherein the sound signal is an audio signal of a sound produced by a person.
11. A method according to claim 10 , wherein the sound comprises one or more of the group of: humming, singing and whistling at least a portion of a piece of music.
12. Apparatus for use in use in detecting the pitch values of notes in a musical sound signal, operable according to the method of claim 1 .
13. Apparatus for detecting the pitch values of notes in a musical sound signal, comprising:
means for identifying one or more voiced segments in the sound signal using an energy function of the sound signal;
means for applying a gradient-based processing to said voiced segments for dividing each voiced segment into one or more notes; and
means for deriving pitch values of the respective notes in the sound signal.
14. Apparatus according to claim 13 , wherein said means for applying a gradient-based processing uses note markers to isolate notes.
15. Apparatus according to claim 14 , wherein the means for deriving the pitch values of the respective notes divides portions of each voiced segment between the note markers into blocks.
16. Apparatus according to claim 15 , wherein each portion contains the same number of blocks.
17. Apparatus according to claim 13 , wherein the means for deriving the pitch values of the respective notes is operable to apply k-mean clustering on block pitch values derived for the blocks between the note markers.
18. Apparatus according to claim 13 , further comprising means for rounding the derived pitch values of the respective notes to the nearest note values.
19. Apparatus according to claim 13 , wherein the means for identifying the voiced segments operates based on a determination of silences in the sound signal.
20. Apparatus according to claim 13 , further comprising means for extracting notes from said pitch values to create note descriptors.
21. Apparatus according to claim 13 , operable to process a digital musical sound signal.
22. Apparatus according to claim 13 , operable to process a musical sound signal being an audio signal of a sound produced by a person.
23. Apparatus according to claim 22 , wherein the sound comprises one or more of the group of: humming, singing and whistling at least a portion of a piece of music.