Sherrod Williams, Chadwick Barksdale and appellant were tried separately for the murder and armed robbery of one victim. Williams’ trial ended when he pled guilty to armed robbery and the murder charge was dismissed. Barksdale’s trial resulted in his conviction on both charges, but this Court reversed. Barksdale v. State, 265 Ga. 9 (453 SE2d 2) (1995). Appellant’s trial resulted in a guilty verdict on both charges and he appeals from the judgments of conviction and sentences entered by the trial court on the jury’s guilty verdicts.1
1. The evidence shows that appellant and Barksdale fatally shot the victim, and that they also stole money and drugs from him. Thus, the jury was authorized to find appellant guilty of murder and armed robbery beyond a reasonable doubt. Jackson v. Virginia, 443 U. S. 307 (99 SC 2781, 61 LE2d 560) (1979); Barksdale v. State, supra at 10 (1).
2. In an interview with officers, Williams denied his participation in the crimes, but admitted his subsequent knowledge thereof. Williams then agreed to place a recorded telephone call to Barksdale. During this recorded call from Williams, Barksdale implicated appellant in the crimes. Over appellant’s hearsay objection, the trial court admitted the recorded call into evidence. Appellant enumerates this evidentiary ruling as error.
OCGA § 24-3-5 recognizes an exception to the hearsay rule for the statements of a co-conspirator. Although Williams may have terminated his participation in the conspiracy by the time he placed the recorded call, Barksdale was still conspiring to conceal the crime. Gunter v. State, 243 Ga. 651, 661-662 (7) (256 SE2d 341) (1979). Williams’ voluntary participation in the recording of the call would not alter the basic admissibility of Barksdale’s statements under Gunter v. State, supra, as the electronic interception of the conversation cre*814ated a recording of Barksdale’s statements, which statements Williams could have related if he had been a witness. Duren v. State, 177 Ga. App. 421, 422 (1) (339 SE2d 394) (1986). See also Ramsey v. State, 165 Ga. App. 854, 858 (4) (303 SE2d 32) (1983). Accordingly, the statements made by Barksdale in the recorded call were admissible under the exception to the hearsay rule recognized by OCGA § 24-3-5.
The statements made by Williams during the recorded call would not be admissible pursuant to OCGA § 24-3-5 if he was no longer a co-conspirator. Crowder v. State, 237 Ga. 141, 153 (227 SE2d 230) (1976). However, the recording of the call was offered only for the limited purpose of showing the content of Barksdale’s statements to Williams.
Sometimes an utterance is merely a part of the surrounding circumstances of an occurrence. Such statements are not offered to prove the fact asserted in the statement. . .. Proof of such statements is original evidence; it is not an exception to hearsay.
Green, Ga. Law of Evidence (4th ed.), § 288. Here, the statements made by Williams to Barksdale were necessary to explain why Barks-dale responded in the way that he did. “When, in a legal investigation, . . . conversations ... are facts to explain conduct and ascertain motives, they shall be admitted in evidence not as hearsay but as original evidence.” OCGA § 24-3-2. It follows that Williams’ statements in the recorded call would be admissible as part of reciprocal and integrated utterances between him and Barksdale, for the limited purpose of putting Barksdale’s responses in context and making Barksdale’s statements intelligible to the jury and recognizable as the statements of a co-conspirator. See United States v. Gutierrez-Chavez, 842 F2d 77, 81 (5th Cir. 1988). There is no contention that any of Williams’ statements in the recorded call were affirmatively prejudicial to appellant. Compare United States v. Alonzo, 991 F2d 1422, 1426-1427 (8th Cir. 1993); United States v. Smith, 578 F2d 1227, 1233, 1238 (8th Cir. 1978). Moreover, our own review of the transcript of the recorded call shows that none of Williams’ statements therein was inculpatory of appellant. Furthermore, appellant’s general hearsay objection to the admission of all of Williams’ statements was properly overruled so long as any of those statements was not hearsay and was admissible as original evidence under OCGA § 24-3-2. Willis v. State, 263 Ga. 70, 71 (2) (428 SE2d 338) (1993); Porter v. Chester, 208 Ga. 309, 310 (3) (66 SE2d 729) (1951).
3. Appellant also contends that the admission of the recorded call deprived him of his right to confront the witnesses against him. Con*815trary to appellant’s contention, however, the declarant’s unavailability is not a prerequisite to the admission of a co-conspirator’s statements. United States v. Inadi, 475 U. S. 387 (106 SC 1121, 89 LE2d 390) (1986); Gay v. State, 249 Ga. 747, 751 (3) (294 SE2d 476) (1982). All that is required is sufficient indicia of reliability as set forth in Dutton v. Evans, 400 U. S. 74 (91 SC 210, 27 LE2d 213) (1970). Bourjaily v. United States, 483 U. S. 171,183 (107 SC 2775, 97 LE2d 144) (1987); Mooney v. State, 243 Ga. 373, 390 (3) (254 SE2d 337) (1979). The statements made by Williams in the recorded call were not admissible under the co-conspirator exception to the hearsay rule, but as original evidence. With regard to Barksdale’s statements in the recorded call, appellant does not assert, and we do not find, a lack of sufficient indicia of reliability. See Mooney v. State, supra at 390 (3).
Appellant’s remaining contentions regarding admission of the recorded call were not specifically raised by objection at trial and cannot now be raised for the first time on appeal. Brown v. State, 250 Ga. 862, 866 (4) (302 SE2d 347) (1983); McGee v. State, 205 Ga. App. 722, 726 (9) (423 SE2d 666) (1992).
4. In the recorded call, Williams’ possible submission to a polygraph test was mentioned. After the recording of the call was played for the jury, appellant elicited testimony that Williams did take a polygraph test subsequent to the call, and then submitted a statement which differed from that he originally made. Over appellant’s objection, the trial court admitted the statement made by Williams prior to his polygraph test, on the ground that appellant opened the door to its admission. This ruling is enumerated as error.
Appellant contends that the door was opened only to admission of the results of Williams’ polygraph test and not to admission of Williams’ prior statement. However, the testimony elicited by appellant that Williams changed his story after the polygraph test did open the door to inquiry concerning Williams’ first statement. See Beasley v. State, 202 Ga. App. 349 (1) (414 SE2d 663) (1991). Appellant does not contend on appeal that, even if he opened the door to inquiry concerning Williams’ first statement, that statement itself nevertheless was inadmissible hearsay. Compare Pierce v. State, 176 Ga. App. 795, 796 (2) (338 SE2d 40) (1985); Green v. State, 115 Ga. App. 685, 689 (2) (155 SE2d 655) (1967). Accordingly, we find no reversible error in the trial court’s admission into evidence of Williams’ first statement.
5. The admission of evidence that appellant purchased cocaine on the day of the homicide is enumerated as error. Appellant purchased the cocaine from the same person who later told the victim that appellant wanted to purchase more drugs. Thereafter, the victim left with appellant and later became the victim of a homicide. Evidence of appellant’s purchase of the cocaine was admissible as part of the res *816gestae. Leutner v. State, 235 Ga. 77, 79 (3) (218 SE2d 820) (1975).
Judgment affirmed.
All the Justices concur, except Fletcher, P. J., and Sears, J., who concur specially.The crimes occurred on January 25, 1993. Appellant was indicted on March 17, 1993. The verdicts were returned and the sentences were imposed on April 5, 1994. Appellant’s motion for new trial was filed on April 20, 1994 and denied on April 20, 1995. His notice of appeal was filed on April 21, 1995. The case was docketed in this Court on May 5, 1995 and was orally argued on July 10, 1995.