Use 4 electrode type connector.
like:
http://www.amazon.com/StarTech-com-headsets-separate-headphone-microphone/dp/B004SP0WAQ/ref=sr_1_fkmr2_2?ie=UTF8&qid=1450096695&sr=8-2-fkmr2&keywords=3DS+headset+splitter
and the question is YES, but it needs some tricks.
see PetitModem Forums in this site.
Microphone Splitter suggestions
JustGreatCreated:
I was thinking about getting a microphone splitter for PetitModem, but I wasn't sure which one to buy/how low of a price to expect.
Additionally, I wanted to know; does the microphone input portion of the splitter act as a replacement for the 3DS microphone when plugged into a 3DS?
Thank you in advance.