Q:

Symbolism behind earrings used for the golden calf?

Shemos 32:2-3 tells us that the gold materials requested and used for the making of the golden calf were earrings. The Jews clearly had other gold items, including other golden jewlery (ibid 35:22). Is there any symbolism behind why earrings specifically were chosen? 

A:

BS"D, Hakham Eli Mansour makes this connection 'al pi HaRav Shimon Schwab in his shi'ur on Parashat Ki Tisa 5774 (link, see 17:15-28:00).
HaRav Mansour explains HaRav Schwab by starting with the fact that it was the men who gave the gold from their earrings to Aharon after their wives refused to hand over their jewelry for the purposes of 'Avodah Zarah (for which, he explains, Rosh Hodesh was dedicated to Jewish women). His support for this conclusion is the word "Ozneihem" in Shemot 32:3. HaRav Mansour goes on to ask why men were wearing earrings in the first place.
He explains that, after miraculously hearing HaShem's voice with their own physical ears, the Jewish men wanted to adorn their ears with gold to underscore and remember the miracle (as, he explains, we do with hidurim of many of the mitzwot).
Tangentially, he explains that earrings are a remembrance that we are slaves only to HaShem and that that is why a Jewish slave has his ear pierced on a doorpost for choosing to extend his slavery to another human being. Here, at Mt. Sinai, the Jewish men pierced their ears to honor and remember "Anokhi HaShem Eloqeikha".
He concludes this section of his shi'ur by tying these teachings together to explain why Het Ha'Egel was such a grave sin. The men rushed to use the gold from the earrings they had, only days before, sanctified for the remembrance of hearing HaShem speak and command them to serve Him alone all in order to worship an idol. For this grave sin, they and their descendants came to deserve a severe punishment indeed.

