In the parable of the sower, was everyone capable of hearing the word? Yes. Read for yourself.
Mark 4:14 The sower soweth the word.
15 And these are they by the way side, where the word is sown; but when they have heard, Satan cometh immediately, and taketh away the word that was sown in their hearts.
16 And these are they likewise which are sown on stony ground; who, when they have heard the word, immediately receive it with gladness;
17 And have no root in themselves, and so endure but for a time: afterward, when affliction or persecution ariseth for the word's sake, immediately they are offended.
18 And these are they which are sown among thorns; such as hear the word,
19 And the cares of this world, and the deceitfulness of riches, and the lusts of other things entering in, choke the word, and it becometh unfruitful.
20 And these are they which are sown on good ground; such as hear the word, and receive it, and bring forth fruit, some thirtyfold, some sixty, and some an hundred.
Does Jesus say the unsaved are incapable of hearing his word here? No, he does not, in fact, he clearly states that they indeed did hear his words. And he mentions it twice! The difference is that they did not "receive it" or accept it, which means to believe it from the heart.
Unlike most, I believe only the first hearers (wayside) are unsaved. Those on stony ground and sown among thorns did receive the word and sprung to life. Only they let persecution and the cares of the world hinder them and did not mature and bring forth fruit.
John 12:48 He that rejecteth me, and receiveth not my words, hath one that judgeth him: the word that I have spoken, the same shall judge him in the last day.
So, this doctrine that the unsaved do not have the ability of hearing God's word is absolutely unscriptural as shown in the parable of the sower.