Reply To: Thresh parameter in SourceTracker node

[Masayuki Takigahira]

SourceTracker’s Thresh is a parameter that judges whether the MUSIC spectrum power
of the node connected to the preceding stage such as LocalizeMUSIC or not exceeds the threshold value.
It is difficult to make physical meaning to the value of the MUSIC spectrum itself.
Therefore, there is no unit.

For MUSIC spectral power when LocalizeMUSIC is connected, please refer to the following formula (15) and (16) in the document.
http://www.hark.jp/document/hark-document-en/subsec-LocalizeMUSIC.html

Thresh differs depending on the user’s environment, so there is no recommended value,
but you can know roughly the proper value by the following method.
1. If you set DEBUG parameter to true on the LocalizeMUSIC node, the MUSIC spectrum power in each direction included in the transfer function is output to the stdout.
2. In the result of this stdout, the value of the column whose numerical value rises when you speaking is the value of the MUSIC spectrum power in the sound source direction.
3. You can check the average of the values shown during the speaking periods and the average of the values shown during the silence periods.
4. You fine-adjust the intermediate value of the two values confirmed in step 3. as the initial value of SourceTracker’s Thresh parameter.

Best regards,
m.takigahira