question on pronunciation in Jespersen

[Stahlke, Herbert F.W.]

In a section on the suffices -Vnce and -Vncy, Jespersen writes, "A good deal of vacillation between -nce and -ncy may partly be attributed to the fact that the plurals -nces and -ncies are identical in sound, e. g. inadvertences = inadvertencies, impertinences = impertinencies."  I have never noticed.  To me the pronunciations are distinct.  Would this be a first-half of the 20th c. British pronunciation?


Herb