Problem: the background is grey instead of white (too little contrast)
Solution: reduce the Dynamic range in the spectrogram settings. The standard value is 50 dB, which is fine for detecting small things like plosive voicing in well recorded speech. For gross features like vowel formants, or for noisy speech, you may want to change the dynamic range to 40 or even 30 dB.
© ppgb 20030916