6 Node References

This chapter describes detail information of each node. How to read node references are described first.

How to read data type

  1. Outline: Types of the data that the data type means are described.

  2. Node converted into this type: When the data in the type is needed, which node should be used is described.

How to read file format

  1. Outline: For what the format is used is described.

  2. Nodes that use files in this format: For what nodes the file format is needed is described.

  3. Creation method: How a file in the format is created is described.

  4. Format: File formats are described in detail.

How to read node reference

  1. Outline of the node: What function the node provides is described. The user may read them when wishing to know roughly about the functions.

  2. Necessary file: The file required to use the node is described. This file links to the description of Section 5 season. Details of the contents of the file are described in Section 5.

  3. Usage: Concrete connection examples are described for the cases the nodes should be used. When the user somehow wishes to use the node concerned, it is recommended to just to try the example.

  4. Input-output and property of node: Types and meaning of the input and output terminals of nodes are described. Moreover, parameters to be set are shown in tables. For parameters for which detailed descriptions are required, descriptions are added for each of such parameters after the table.

  5. Details of the node: Detail descriptions including theoretical background and implementation methods of nodes are described. When the user wishes to know about the node concerned, it is recommended for them to read this.

Definition of symbols

Symbols used in this document are defined as Table 6.1.Moreover, the following notations are used implicitly.

  • Lower case characters and upper case characters indicate time domain and frequency domain, respectively.

  • Vectors and matrixes are transcribed in bold face.

  • Transpose of a matrix is expressed with $^ T$ and Hermitian transpose is expressed with in $^ H$. ($X^ T, X^ H$)

  • A hat is added to the estimated value (e.g. An estimated value of $x$ is $\hat x$)

  • $x$ is used for inputs and $y$ is used for outputs.

  • $ \boldsymbol W $ is used for separation matrixes and $ \boldsymbol H $ is used for transfer function matrixes.

  • Channel numbers are represented by subscript. (e.g. The signal source of the third channel is $s_3$)

  • Time and frequency are represented in $()$. (e.g. $X(t, f)$)

Table 6.1: Symbol list

Variable name



Index of microphone


Number of microphone

$m_1, \cdots , m_ M$

Symbol indicating each microphone


Index of sound source


Number of sound source

$s_1, \cdots , s_ N$

Symbol indicating each sound source


Index of frequency bin


Number of frequency bin

$k_0 \cdots k_{K-1}$

Symbol indicating frequency bin

$\omega $



Number of FFT point


Shift length


Window length

$\pi $

Circular constant


Imaginary unit


Scalar variable

$\boldsymbol {x}$

Vector variable

$ [x(1),\dots ,x(D)]$

D-dimensional row vector

$ [x(1),\dots ,x(D)]^ T$

D dimensional column vector