首楞嚴義疏注經 3.190

3.190

「聞聲同識破。初三句雙牒，汝謂識因聲生，又許因根有相，今聞聲時即是聞識。

This is the refutation based on hearing sound being identical to hearing consciousness. The first three sentences cite both premises: you claim that consciousness arises due to sound, and you also grant that sound has its characteristic due to the sense faculty; now, when one hears sound, that would be hearing consciousness.