Some of the Fodsports intercom models can support you listen to music while intercom.

For example, Fodsports FX8 Pro, FX7 and FX 10C support wireless mixing. They can directly support you listen to music while intercom, without a wired audio cable.

Besides, Fodsports M1-S PRO, M1-S PLUS, M1-S AIR, Fx8, FX8 AIR support wired mixing.
These intercoms have 2.5mm audio interfaces for you to plug in the audio cable. Then you can transfer it to the 3.5mm adapter on the phone to achieve mixing.