Plaintiff-relator is the defendant in a Multnomah County Circuit Court criminal proceeding. He is charged in a four-count indictment with third degree rape and sodomy. The parties do not dispute that relator has complied with the statutory prerequisites entitling him to a pretrial hearing under OEC 4121 to determine the admissibility of evidence of the victim’s past sexual behavior.
The trial court judge, who is the defendant in this mandamus proceeding, ruled that relator was entitled to a pretrial OEC 412 hearing and that the hearing would be closed to the public pursuant to OEC 412(3)(b), which provides that “the court shall order a hearing in chambers to determine if such evidence is admissible.” In this mandamus proceeding, relator seeks a writ requiring the trial court judge to vacate the order excluding the public from the OEC 412 hearing.2 We *289issued an alternative writ of mandamus, requiring that the trial court judge vacate the order or show cause why she should not. Now (after pleading, briefing, and argument), we issue a peremptory writ of mandamus.
As a preliminary matter, we recognize that a writ of mandamus “shall not be issued in any case where there is a plain, speedy and adequate remedy in the ordinary course of the law.” ORS 34.110. The parties dispute whether appeal would prove to be an adequate remedy in this case, precluding the issuance of the writ.
Unlike in the ordinary criminal or civil case, including cases involving various statutory evidentiary privileges and motions to suppress based on unconstitutional searches and seizures, the nature of the constitutional right that relator asserts under Article I, section 10, of the Oregon Constitution is. not personal to him. Compare, e.g., OEC 503(2) (the client “has” the lawyer-client privilege); State v. Davis, 295 Or 227, 233-35, 666 P2d 802 (1983) (the court will suppress evidence when necessary to vindicate an individual’s constitutional right). As this court held in Oregonian Publishing Co. v. O’Leary, 303 Or 297, 301-02, 736 P2d 173 (1987):
“[T]he command that ‘[n]o court shall be secret’ is not a statement of an individual right that may be waived or compromised by the individual. [State ex rel Oregonian Pub. Co. v. Deiz, 289 Or 277, 282-83, 613 P2d 23 (1980).] Members of the media and the public may benefit from, and assert in court in their own behalf, the prohibition of section 10 on secret courts, but the prohibition is not a right that is personal to themselves. Rather, it ‘is one of those provisions of the constitution that prescribe how the functions of government shall be conducted.’ Deiz, 289 Or at 288 (Linde, J., concurring).’’
If relator is not convicted at trial ór if relator enters into a plea agreement, there can be no appeal to raise the issue of the constitutionality of the closed OEC 412 hearing. ORS 138.040,138.050, and 138.053. Moreover, if relator is correct, the very fact that a closed hearing was held, no matter what *290follows thereafter, arguably is a separate harm that cannot be undone. In this unusual circumstance, then, appeal would not bean adequate legal remedy to vindicate the rights claimed to be at stake. Mandamus, therefore, may be appropriate, even though in our disposition we do not need to reach the constitutional claim.
Although the text of the statute is ambiguous, the state (in defending the constitutionality of the statute) and relator (in attacking it) agree that “in chambers” means “outside the presence of the public and the jury.” Our review of the text of the “in chambers” provision, the intent of the legislature discernible from the text and context of OEC 412 generally, and the intent of the legislature discernible from the legislative history, leads us to a different conclusion. See ORS 174.010, 174.020.
“In chambers” is not defined in the Oregon Evidence Code, nor is it a term that is susceptible of only one meaning. It could mean that the hearing must not take place in the courtroom but rather must take place in the judge’s office, commonly referred to as the judge’s “chambers.” This meaning carries with it no necessary exclusionary scope, although it reasonably implies the exclusion of at least the jury, and it could result in some de facto exclusion of others by virtue of the location and size of the office.
“In chambers” instead could have a meaning akin to that of an “in camera” proceeding, which can entail various levels of mandatory exclusion, including exclusion of the public and exclusion of one or more parties or counsel. See, e.g., OEC 510(4)(c) {in camera proceedings relating to the disclosure of the identify of a government informant).
Moving from the term “in chambers” itself to the legislative intent discernible from the text and context of OEC 412 more generally, OEC 412 is a statute “the principal purpose of [which] is to protect victims of sexual crimes from the degrading and embarrassing disclosure of intimate details about their private lives.” Legislative Commentary to OEC 412, reprinted in Kirkpatrick, Oregon Evidence 202 (2d ed 1989). That goal is accomplished primarily by defining the scope of relevant admissible evidence narrowly and by conducting the admissibility hearing “in chambers.”
*291Turning from the text and context of “in chambers” to its legislative history, we find the history to be of value in discerning the legislature’s intent. The provision of the Rape Shield Law that is under attack in this case has evolved from a form of the statute first enacted in 1975. The 1975 law provided that “the court shall conduct [the admissibility] hearing out of the presence of the jury.” Or Laws 1975, ch 176, § 2(4) (codified as ORS 163.475(4)). In 1977, ORS 163.475 was amended to require the admissibility hearing to be held before trial except for good cause shown. Or Laws 1977, ch 822, § 1. The 1977 amendments also added the additional terme ‘and the public’ ’ to the phrase “out of the presence of the jury.” Id. ORS 163.475 was replaced in 1981 with the adoption of the Oregon Evidence Code and the enactment of OEC 412 in its present form, requiring that the hearing be held “in chambers.” Or Laws 1981, ch 892, § 31.
The 1981 enactment of OEC 412 occurred against the backdrop of a then-recent decision of this court, holding that Article I, section 10, of the Oregon Constitution, forbade the closing of a juvenile court proceeding to the press. State ex rel Oregonian Pub. Co. v. Deiz, 289 Or 277, 613 P2d 23 (1980). Deiz was a significant decision, both for the fact that it was this court’s first authoritative construction of Article I, section 10, and for its implications for a variety of traditionally closed proceedings.
At the time that the legislature considered and enacted OEC 412 in 1981, an appellate case was pending that questioned the effect of Deiz on the closed-hearing requirement of ORS 163.475, the predecessor to OEC 412. After the 1981 legislative session ended, a divided Court of Appeals upheld the validity of ORS 163.475, review was allowed by this court, and then review was dismissed by this court because of the limited scope of the issue presented by the ruling under a repealed statute. State v. Blake, 53 Or App 906, 633 P2d 831 (1981), rev dismissed, 292 Or 486, 640 P2d 605 (1982).3 In dismissing that proceeding, this court stated: “When we are required to apply *292the phrase ‘in chambers’ it will be necessary to judicially construe the phrase.” 292 Or at 489.
The term “in chambers” was not discussed on the floor of either the Oregon House or Senate. The terms “in camera” and “in chambers” apparently were used interchangeably in committee discussions, with no precise meaning. The term “in chambers” appears in Federal Rule of Evidence 412, upon which OEC 412 was based in part, but the term is not defined in that rule, either. The dissent correctly notes that federal legislative histoiy suggests that one intended purpose of an “in chambers” hearing under FRE 412 was to protect the privacy of victims of rape. The legislation that added the requirement for an ancillary hearing under the Federal Rules of Evidence, H.R. 4727, was, in fact, titled “Privacy Protection for Rape Victims Act of 1977.” Its original author stated: “The purpose of [the legislation] is to make the prosecution of Federal rape cases more effective and equitable for rape victims, and to serve as a model statute for State laws.” 124 Cong. Rec. 36,256 (1978) (statement of Senator Bayh). Professors Wright and Graham reasonably concluded from the floor debates that, in choosing the “in chambers” phrasing, “Congress was obviously concerned about the degree of privacy to be afforded rather than the physical location of the hearing.” 23 Wright and Graham, Federal Practice and Procedure 621 n 18, § 5391 (1980). It does not necessarily follow, however, that, by adopting federal wording, Oregon legislators shared the identical intent of their federal counterparts, nor does it necessarily follow that the Oregon Legislative Assembly adopted the federal wording out of a conviction that “in chambers” had a single meaning or that the only way to protect the privacy of rape victims was to exclude the public entirely from preliminary evidentiary hearings.
The Oregon House and Senate committee members did not comment on the constitutionality of the “in chambers” provision or appear to attempt to formulate the scope of the exclusion in light of this court’s decision in State ex rel Oregonian Pub. Co. v. Deiz, supra, issued the year before.4 There *293was no express legislative intent to change the scope of the preexisting exclusion, defined by the predecessor statute, ORS 163.475, to exclude the public and the jury. Indeed, the Legislative Commentary to the Evidence Code and the Advisory Committee Commentary to the Evidence Code5 give some support to a conclusion that the legislature did not intend to change the scope of the existing exclusion.6 The Legislative Commentary states:
“The purpose of the in camera hearing is twofold. It gives the defendant an opportunity to demonstrate to the court why certain evidence is admissible and ought to be presented to the jury. At the same time it protects the privacy of the victim in those instances where the comí; finds that evidence is inadmissible.” Kirkpatrick, Oregon Evidence, supra, at 202.
The Advisory Committee Commentary to its proposed form of OEC 412, which used the term “in chambers,” states that “there must be an in camera hearing — that is, a proceeding that takes place in the judge’s chambers out of the presence of the jury and the general public.” Advisory Committee Commentary, Proposed Evidence Code, 120 (1979). Both commentaries discuss the relationship of OEC 412 to the law that it replaced, but neither commentary states that “in chambers” *294was intended to change the law’s pre-existing exclusion of the public and the jury.
Although one reasonably could read OEC 412(3) (b) to require public exclusion from the OEC 412 hearing, we believe that the other possible interpretation is the better one. “In chambers,” as used in OEC 412(3)(b), means that the hearing must take place in the judge’s office, commonly referred to as the judge’s “chambers.” The statute does not categorically exclude the public from attending.
This interpretation has several virtues. First, it reflects a common usage of the statutory term. See Perez v. State Farm-Mutual Ins. Co., 289 Or 295, 299, 613 P2d 32 (1980) (in the course of holding that “disability” does not include death, the court stated that, “[i]n construing a statute, words of common usage are to be given their natural, plain and obvious meaning”). “In chambers” as commonly refers to the place of a proceeding — the judge’s office — as it does to the range of people who may attend the proceeding. Black’s Law Dictionary 230 (6th ed 1990). Moreover, a customary “in chambers” proceeding may, in fact, be open: “We know from experience [that] a hearing ‘in chambers’ is not always in practice one at which everyone except the judge, court officers, the parties, the attorneys, and perhaps the witness is necessarily excluded.” State v. Blake, supra, 292 Or at 488-89. In OEC 412, the legislature did not use the term “in camera,” which ordinarily carries with it some necessarily exclusionary scope. See, e.g., OEC 510(4)(c) (“in camera” proceedings relating to informant’s identity); State ex rel Carlile v. Lewis, 310 Or 541, 544-45, 800 P2d 786 (1990) (interpreting “in camera,” in ORS 135.873(2) in respect of protective orders).
Second, this interpretation of “in chambers” reflects legislative history. In 1981, the legislature repealed a statute that provided that hearings of the kind at issue shall be conducted “out of the presence of the jury , and the public.” ORS 163.475 (1979). (Emphasis added.) The legislature replaced that wording, to provide instead for hearings conducted “in chambers.” Or Laws 1981, ch 892, § 31. This court has held that a material change in statutory wording presumptively signifies a change in meaning. Fifth Avenue Corp. v. Washington Co., 282 Or 591, 597, 581 P2d 50 (1978); Roy L. Houck & Sons v. Tax Com., 229 Or 21, 32, 366 P2d 166 (1961). The parties would *295interpret the new wordingto mean exactly the same thing as the old, different wording. That result is permissible, but it affords no substantive or presumptive recognition to the fact that there was an obvious legislative departure from clear pre-existing statutory text.
Third, this interpretation is in harmony with legislative intent. As we noted, 312 Or at 290, the principal purpose of OEC 412(3)(b) is “to protect victims of sexual crimes from the degrading and embarrassing disclosure of intimate details about their private lives.” There is no doubt that a hearing in a smaller, less exposed, and less intimidating setting — in chambers — is less degrading and less embarrassing than a courtroom hearing. The legislature, consistent with its general purpose, could have meant to provide for a hearing in chambers.7
For each of these reasons — acceptable common usage of the statutory term and consistency with both the evolution and the purpose of the law — we conclude that OEC 412(3)(b) requires that the hearing to determine admissibility of evidence of the victim’s past sexual behavior shall be held in the judge’s chambers. OEC 412(3)(b) does not mandate public exclusion from that hearing.
The trial court judge acted in reliance upon her conclusion that OEC 412(3)(b) mandated a hearing closed to the public. The trial court judge, therefore, acted under an erroneous perception of her legal duty. A peremptory writ of mandamus is appropriate to require the trial court judge to vacate the closure order and to permit her to reconsider the issue of public exclusion under a correct interpretation of the statute.
Peremptory writ to issue requiring vacation of order of circuit court.
OEC 412, which also is known as the “Rape Shield Law,” provides, in part:
“(2) Notwithstanding any other provision of law, in a prosecution for a crime described in ORS 163.355 to 163.425, * * * evidence of a victim’s past sexual behavior * * * is * * * not admissible, unless such evidence other than reputation or opinion evidence is:
“(a) Admitted in accordance with paragraphs (a) and (b) of subsection (3) of this section; and
“(b) Is evidence that:
“(A) Relates to the motive or bias of the alleged victim; or
“(B) Is necessary to rebut or explain scientific or medical evidence offered by the state; or
“(C) Is otherwise constitutionally required to be admitted.
“ (3)(a) If the person accused of committing rape, sodomy or sexual abuse or attempted rape, sodomy or sexual abuse intends to offer under subsection (2) of this section evidence of specific instances of the alleged victim’s past sexual behavior, the accused shall make a written motion to offer such evidence * * *.
“(b) The motion described in paragraph (a) of this subsection shall be accompanied by a written offer of proof. If the court determines that the offer of proof contains evidence described in subsection (2) of this section, the court shall order a hearing in chambers to determine if such evidence is admissible. At such hearing the parties may call witnesses, including the alleged victim, and offer relevant evidence. Notwithstanding ORS 40.030(2), if the relevancy of the evidence which the accused seeks to offer in the trial depends upon the fulfillment of a condition of fact, the court, at the hearing in chambers or at a subsequent hearing in chambers scheduled for such purpose, shall accept evidence on the issue of whether such condition of fact is fulfilled and shall determine such issue.”
Relator’s petition for a writ of mandamus relies on Article I, section 10, of the Oregon Constitution (“[n]o court shall be secret, but justice shall be administered, *289openly and without purchase * * *”); Article I, section 11, of the Oregon Constitution (the “right to public trial”); and the First and Sixth Amendments to the United States Constitution (free speech and public trial). Our decision, which concludes that public exclusion from the “in chambers” hearing is not required by OEC 412, obviates any need to address relator’s constitutional contentions, and we express no opinion concerning them.
Neither the briefing nor the argument in State v. Blake, 53 Or App 906, 633 P2d 831 (1981), rev dismissed, 292 Or486, 640 P2d 605 (1982), had advised the court of the pertinent 1981 statutory change. The proceeding was dismissed when this court became aware of the change while the case was under advisement. Id. at 488.
One committee witness noted the issue raised by State ex rel Oregonian Pub. Co. v. Deiz, 289 Or 277, 613 P2d 23 (1980), observed the pendency of a case in the appellate courts challenging the exclusion of the public from the rape victim’s hearing under ORS 163.475 (presumably State v. Blake, supra), and assumed that *293the courts would resolve the issue. Testimony of Jim McCandlish, representing the Oregon Criminal Defense Lawyers Association, before the Senate Committee on Justice: Tape, July 22, 1981, H-81-JUD-311B, at 113-25. The Oregon District Attorneys Association warned the committee in another context that, in light of State ex rel Oregonian Pub. Co. v. Deiz, supra, “there might be substantial constitutional problems with a procedure which allows for a closed in camera hearing.” Report to Joint Interim Committee on the Judiciary regarding HB 2030 Article V Privileges, § 38 (1981).
The Advisory Committee on Evidence Law Revision was appointed in 1974 by the Law Improvement Committee, a legislatively-created body. The Advisory Committee was composed of practicing lawyers, judges, and law professors. In September 1979, the committee submitted a proposed new Evidence Code, accompanied by an extensive commentary. That proposed code and commentary provided the foundation for the work of the Subcommittee on Evidence of the Interim Judiciary Committee during 1979-80. The subcommittee’s version of the code, with the Advisory Committee’s Commentary as supplemented, was submitted for consideration to the 1981 Legislative Assembly, which adopted the Oregon Evidence Code. Kirkpatrick, Oregon Evidence, xxix-xxx (2d ed 1989).
We are not bound by the Commentary but do recognize it as useful background concerning rules of evidence. State ex rel Juv. Dept. v. Ashley, 312 Or 169, 179, 818 P2d 1270 (1991); State v. McClure, 298 Or 336, 344, 692 P2d 579 (1984).
Contrary to the dissent’s assertion, we would not necessarily effectuate the legislative intent to protect rape victims by construing “in chambers” to require exclusion of the public. We have taken notice of the possibility that such an interpretation of “in chambers” might conflict with Article I, section 10, of the Oregon Constitution. State v. Blake, supra, 292 Or at 489.
Moreover, striking “in chambers” from OEC 412(3)(b) would result in requiring courts to hold evidentiary hearings regarding a rape victim’s sexual history in open court, a result which clearly does not comport with the legislature’s intent to protect victim privacy.