What are F0 counters in Speech signals? What is represented by F0?
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  To begin with, let’s remember what the fundamental frequency is and in
  what tasks it may be needed. The fundamental frequency, which is also
  referred to as F0, is the vibration frequency of the ligaments when
  pronouncing voiced sounds. When pronouncing unvoiced sounds, for
  example, by whispering or uttering hissing and whistling sounds, the
  ligaments do not vibrate, which means that this characteristic is not
  relevant.
  *Note that the split on voiced/unvoiced sounds is not equivalent to the split on vowels and consonants.
  
  The variability of the fundamental frequency is quite large, and it
  can vary greatly not only between people (for lower average male
  voices the frequency is 70–200 Hz, and for women it can reach 400 Hz),
  but also for one person, especially in emotional speech.
  
  F0 is used in a wide range of solutions:

Emotion Recognition
Sex determination (male/female voices)
Speaker deterioration, or splitting the speech into phrases
In healthcare, detection of the pathological characteristics of the voice (for example, using the acoustic parameters of Jitter and

  
  Shimmer): F0 could be used for the detection of signs of Parkinson’s
  disease 1; Jitter and Shimmer can also be used for Emotion
  Recognition