This node converts signals of frequency domain into waveforms of time domain.
No files are required.
This node is used to convert signals of frequency domain into waveforms of time domain.
When to use
Parameter name 
Type 
Default value 
Unit 
Description 
LENGTH 
512 
[pt] 
FFT length 

ADVANCE 
160 
[pt] 
Shift length 

SAMPLING_RATE 
16000 
[Hz] 
Sampling rate 

MIN_FREQUENCY 
125 
[Hz] 
Minimum frequency 

MAX_FREQUENCY 
7900 
[Hz] 
Maximum frequency 

WINDOW 
HAMMING 
Window function 

OUTPUT_GAIN 
1.0 
Output gain 
Input
: Map<int, ObjectRef> type. ObjectRef is Vector<complex<float> > .
Output
: Map<int, ObjectRef> type. ObjectRef is Vector<float> .
Parameter
FFT length; must be equal to the other node (MultiFFT ).
Shift length; must be equal to the other node (MultiFFT ).
Sampling rate; must be equal to the other nodes.
The minimum frequency used for waveform generation
The maximum frequency used for waveform generation
Window function. Select HAMMING, RECTANGLE or CONJ
Output gain
Inverse FFT is performed on four low bands of the input signals of the frequency domain by substituting 0 for frequency bins over $\omega _ s/2100$ [Hz]. A designated window is adopted for overlapadd processing, a method of reducing the influence of a window by performing inverse transformation for every frame, adding the signals for which the time domains are shifted back while shifting them. For details, see the web pages in References. Finally, the temporal waveforms are multiplied by the output gain and output. Further, subsequent frames must be read for overlapadd processing; therefore, this node delays the entire processor. The length of the delay can be calculated as:
\begin{equation} delay = \left\{ \begin{array}{@{\, }ll} \left \mathrm{LENGTH}/\mathrm{ADVANCE} \right 1,& {if~ ~ } \mathrm{LENGTH} \, mod\, \mathrm{ADVANCE} \ne 0,\\ \mathrm{LENGTH}/\mathrm{ADVANCE}, & {otherwise}. \end{array} \right. \end{equation}  (176) 
Since the default values for HARK are LENGTH = 512 and ADVANCE = 160, the delay is three frames, which resulting in a 30 [ms] delay for the entire system.
(1) http://en.wikipedia.org/wiki/Overlapadd