[quote=Expllo]
Shinigami actually are able to communicate with their Zanpakuto without using Jinzen, and vice versa. It's just not as clear as it would be when in Jinzen, though I think it does require more concentration or silence to hear your spirit clearly, but I don't think you can have full on conversations without using Jinzen as the signal would be sorta fucked without it.
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I thought that the Zanpakuto spirits were extensions of the Shinigami's soul so they'd have a strong connection and communicating with them often either through mind or 'Jinzen' would keep the communication strong, and since they are extension of the Shinigami, it shouldn't be difficult to communicate through mind o.O