Certain aspects of Porter’s proposal have a long history and have been rejected by a not insignificant collection of NT scholars.
While Moulton (Proleg. p 66) or Turner who softens the certainty of Moulton (Syntax, p 233) might be cited in support of Porter, F.F. Bruce (Acts NICNT 1954, 1988), Moule (Idiom Book NTG p 36) C.K. Barrett (Acts ICC) claim that the distinction between ἀκούω w/genitive and w/accusative is a classical one that doesn’t hold for Koine and particularly not Luke-Acts. For nuanced treatments of the issue see Zerwick §69 and BDF §173.
H. A. W. Meyer
ἈΚΟΎΟΝΤΕς ΜῈΝ Τῆς ΦΩΝῆς] does not agree with Acts 22:9. See the note on Acts 9:3 ff. The artificial attempts at reconciliation are worthless, namely: that Τῆς ΦΩΝῆς, by which Christ’s voice is meant, applies to the words of Paul (so, against the context, Chrysostom, Ammonius, Oecumenius, Camerarius, Castalio, Beza, Vatablus, Clarius, Erasmus Schmid, Heumann, and others); or, that φωνή is here a noise (thunder), but in Acts 22:9 an articulate voice (so erroneously, in opposition to Acts 9:4, Hammond, Elsner, Fabricius, ad Cod. Apocr. N. T., p. 442, Rosenmüller, Morus, Heinrichs); or, that ἤκουσαν in Acts 22:9 denotes the understanding of the voice (so, after Grotius and many older interpreters, in Wolf, Kuinoel, and Hackett), or the definite giving ear in reference to the speaker (Bengel, Baumgarten), which is at variance with the fact, that in both places there is the simple contradistinction of seeing and hearing; hence the appeal to John 12:28-29 is not suitable, and still less the comparison of Daniel 10:7.
Henry Alford
In ch. 22:9, οἱ δὲ σὺν ἐμοὶ ὄντες τὸ μὲν φῶς ἐθεάσαντο [κ. ἔμφοβοι ἐγένοντο], τὴν δὲ φωνὴν οὐκ ἤκουσαν τοῦ λαλοῦντός μοι. Two accounts seemingly (and certainly, in the letter) discrepant; but exceedingly instructive when their spirit is compared,—the fact being this: that the companions of Saul saw and were struck to the ground by the light, but saw οὐδένα, no person:—that they stood (or ‘were fixed:’ > but I should acknowledge the discrepancy here, and recognize the more accurate detail of ch. 26:14, that they fell to the ground) mute, hearing τῆς φωνῆς, the sound of the voice, but not τὴν φωνὴν τοῦ λαλοῦντός μοι, the words spoken and their meaning. Compare John 12:29, note. (Only no stress must be laid on the difference between the gen. and acc. government of φωνή, nor indeed on the mere verbal difference of the two expressions;—but their spirit considered, in the possible reference which they might have to one and the same fact.> )
Two classes of readers only will stumble at this difference of the forms of narration; those who from enmity to the faith are striving to create or magnify discrepancies,—and those who, by the suicidal theory of verbal inspiration, are effectually doing the work of the former. The devout and intelligent student of Scripture will see in such examples a convincing proof of the simple truth of the narrative,—the absence of all endeavour to pare away apparent inconsistencies or revise them into conformity,—the bonâ fide work of holy truthful men, bearing each his testimony to things seen and heard under the guidance, not of the spirit of bondage, but of that Spirit of whom it is said, οὗ τὸ πνεῦμα κυρίου, ἐλευθερία.
I should not too hastily determine that this account has not come from Saul himself, on account of the above differences: they are no more than might arise in narrations at different times by the same person.
Citing Alford and Meyer doesn’t imply that I agree with them. They are 19th century NT scholars of significant stature. Worth reading which is why you find them still cited in technical commentaries published in the third millennium.