trying to convert the time scale of a signal visualized on a spectrogram in sec/msec.
the spectrogram has been calculated using known values of
1) sampling frequency (20k)
2) window size (in samples) (1024)
3) overlap (0.9)
4) total duration of the recording in samples (tspec = 11755)
5) total duration of the recording in seconds (60)
calculation of the total duration in seconds: total duration (samples) / total duration (seconds)
-> length(tspec)/60 = 195.9167
calculation of the signal duration in sec = duration of signal in samples / 195.9167
is this correct or is there any smearing of the signal time units due to nfft and overlap ?