Are sounds gendered? Yes. Does the gender of sounds change over time?
From the surprisingly interesting blog of Laura Wattenberg comes these graphs showing that popular masculine endings to names has changed over time.
No dramatic changes from 1906 to 1956, but then, in 2006, n is triumphant!
Laura also offers some data showing how boy and girl name endings have shifted since the 1880s:
This figure, relatedly, shows trends in the endings of girl babies’ names in France:
UPDATE: In the comment thread, Sator Arepo notes:
Sounds are not equal to letters. The graphs are misleading in that they (with exception of the French language spectrograph-like pictures) they equate the sound of the end of the name with the appearance of the letter in the written word.
Commenter pfctdayelise notes something similar, above. However, it’s even more misleading in the tables, and would depend widely on the origin of a name whether and how certain letters were pronounced.