English Linguistic

Hi to all
I do not quite understand the content of the phonetics/phonology lectures ( especially concepts of consonantal strength/sonority hierarchy and how to refer it to /r/, /h/, /l/ sounds). Maybe anyone could help me to clarify some qs ( especially the question nr 1: sonority/ consonantal strength).

Here they are:

From clear [l] vowel: velarization of [l] in English : make sure u comment on syllable structure + sonority hierarchy

I can explain what velarization of /l/ but what is sonority hierarchy? I guess its not the same as Sonority Sequencing Principle. I think it has to do with the scale (it s on the slides): plosive s are most sonorous sounds and vowels are the least sonorous sounds. Am I right? But is sonority in a way linked to the scale of consonantal strength? How to define consonantal strength? What is the place of /r/, /h/, / l/ sounds in sonority and consonantal strength scales?

And how to explain velarization of [l] in terms of sonority hierarchy

history of 'r' from the point of view of sonority