I am using a so-called speech-shaped stationary white noise, which means so much as a white noise that has been filtered to match the long-term spectrum of a female speaker. The way it was generated has been explained in Luts et al., (2014):
To generate the stationary speech-weighted noise the long-term average speech spectrum (LTASS) of the 500 sentences was determined. For each sentence, silence parts were removed (frames of 20 ms with RMS < 0.001) and the spectrum was calculated with a 4096-points fast Fourier transform using a rectangular window and without overlap. These spectra were then averaged, applying a weight according to the length of each sentence. For this LTASS, a 2048-taps finite impulse response filter was generated and applied on an 11 seconds long white noise.
The original speech used has a fundamental frequency of about 220 Hz, as determined in 'Praat', which makes total sense. 'Praat'analyzes speech by first determining the formants (if I'm right), then it runs an FFT on these window, then looks for the 1st harmonic and call that the F0. However, when I run the speech-shaped stationary noise through Praat, it also recognizes an F0 of about 240 Hz, close to the original speech signal. However,there are no formants in this noise, so I am at a loss here. I thought speech-shaped stationary noise cannot contain harmonic, despite the fact its overall frequency spectrum matches that of speech?
Can speech-shaped stationary white noise contain an F0, or harmonics at all for that matter?