That was actually said regarding the Bible? If so that would be diametrically opposed to John 17:17 "Sanctify them through thy truth: thy word is truth."
Diametrically opposed to the Word is no place for a so-called "living voice of the Church" to be.
Yes, "dumb" as in having no literal physical voice, and "difficult" as compared to the "voice" of the church, which as we know, is so clear that there is not disagreement among its members as to its meaning, as well as magisterial level ). For Rome imagines that only what she says the word of God consists of and means is the Truth,
The RC argument for this basically is that an assuredly (if conditionally) infallible magisterium is essential for determination and assurance of Truth (including writings and men being of God) and to fulfill promises of Divine presence, providence of Truth, and preservation of faith, and authority. And that being the historical instruments and stewards of Divine revelation (oral and written) means that such is that assuredly infallible magisterium. Which of course, she declares herself to be.
Thus any who knowingly dissent from the latter must be in rebellion to God.
Yet the church actually began in dissent from those who sat in the seat of Moses over Israel, (Mt. 23:2) who were the historical instruments and stewards of Scripture, "because that unto them were committed the oracles of God," (Rm. 3:2) to whom pertaineth" the adoption, and the glory, and the covenants, and the giving of the law, and the service of God, and the promises" (Rm. 9:4) of Divine guidance, presence and perpetuation as they believed, (Gn. 12:2,3; 17:4,7,8; Ex. 19:5; Lv. 10:11; Dt. 4:31; 17:8-13; Ps, 11:4,9; Is. 41:10, Ps. 89:33,34; Jer. 7:23)
And instead they followed an itinerant Preacher whom the magisterium rejected, and whom the Messiah reproved them Scripture as being supreme, (Mk. 7:2-16) and established His Truth claims upon scriptural substantiation in word and in power, as did the early church as it began upon this basis. (Mt. 22:23-45; Lk. 24:27,44; Jn. 5:36,39; Acts 2:14-35; 4:33; 5:12; 15:6-21;17:2,11; 18:28; 28:23; Rm. 15:19; 2Cor. 12:12, etc.)
And as is abundantly evidenced, the word of God/the Lord was normally written, even if sometimes first being spoken, and that as written, Scripture became the transcendent supreme substantive standard for obedience and testing and establishing truth claims as the wholly Divinely inspired and assured, Word of God.
Hebrews 4:12 For the word of God is quick, and powerful, and sharper than any twoedged sword, piercing even to the dividing asunder of soul and spirit, and of the joints and marrow, and is a discerner of the thoughts and intents of the heart.