The Sonority Sequencing Prinicple (SSP) uses
      slope to determine the formation of a word.
      Stephen G. Parker "posit[s] that sonority can
      be defined by means of a linear regression
      equation such as the following:
      sonority = a + b × dB, where
      the slope b is positive."1 By putting sonority
      into a function of this type, the relationship
      between sonority, flow, and relative loudness
      can be expressed.
      There's a lot more math in sonority but most of
      what I could find is college level stuff. It pops
      up in some of the links I've left if you want to
      learn more. Thanks for reading. :)
    

       What you see to the left is a sonority graph,
       which graphs the sonority or relative loudness
       of a given word based on something called the
       sonority hierarchy, which ranks sounds according
       to their amplitude relative to other sounds in a
       word. (It should be noted that this
       particular graph is extremely basic; most graphs
       would have a much more comprehensive set of
       syllables.) Math plays a prevalent role in
       quantifying the results of studies in sonority
       and phonology, the branch of linguistics
       involving the study of arrangement of sounds in
       a language.
       By analyzing how syllables in words and phrases
       interact, linguists can guess how ancient
       languages sounded and reconstruct them if
       necessary to demonstrate how modern languages
       may have evolved from ancient ones. Perhaps the
       most practical and widespread use of phonology
       today is in speech recognition and text-to-speech
       technology.
    

      To learn more:
      1diu.edu (On Page 28)
      languagehumanities.org
      onlinelibrary.wiley.com