the statute that governs placing juveniles in adult jail are listed below. Apparently the fact that he can hear the adult inmates falls under the bolded by me:
(A) Bail; Detention.
(1) Bail. Except as provided in subrule (2) the magistrate or court must advise the juvenile of a right to bail as provided for an adult accused. The magistrate or the court may order a juvenile released to a parent or guardian on the basis of any lawful condition, including that bail be posted.
(2) Detention Without Bail. If the proof is evident or if the presumption is great that the juvenile committed the offense, the magistrate or the court may deny bail:
(a) to a juvenile charged with first-degree murder, second-degree murder, or
(b) to a juvenile charged with first-degree criminal sexual conduct, or armed robbery,
(i) who is likely to flee, or
(ii) who clearly presents a danger to others.
(B) Place of Confinement.
(1) Juvenile Facility. Except as provided in subrule (B)(2) and in MCR 6.907(B), a juvenile charged with a crime and not released must be placed in a juvenile facility while awaiting trial and, if necessary, sentencing, rather than being placed in a jail or similar facility designed and used to incarcerate adult prisoners.
(2) Jailing of Juveniles; Restricted. On motion of a prosecuting attorney or a superintendent of a juvenile facility in which the juvenile is detained, the magistrate or court may order the juvenile confined in a jail or similar facility designed and used to incarcerate adult prisoners upon a showing that
(a) the juvenile's habits or conduct are considered a menace to other juveniles; or
(b) the juvenile may not otherwise be safely detained in a juvenile facility.
(3) Family Division Operated Facility. The juvenile shall not be placed in an institution operated by the family division of the circuit court except with the consent of the family division or on order of a court as defined in MCR 6.903(C).
(4) Separate Custody of Juvenile. The juvenile in custody or detention must be maintained separately from the adult prisoners or adult accused as required by MCL 764.27a.
(C) Speedy Trial. Within 7 days of the filing of a motion, the court shall release a juvenile who has remained in detention while awaiting trial for more than 91 days to answer for the specified juvenile violation unless the trial has commenced. In computing the 91-day period, the court is to exclude delays as provided in MCR 6.004(C)(1)-(6) and the time required to conduct the hearing on the motion.
Mich. Ct. R. 6.909
the referenced
MCL 764/27a states as follows:
(3) A juvenile or individual less than 18 years of age who is under the jurisdiction of the circuit court for committing a felony may be confined in the county jail pending trial. An individual less than 18 years of age who is under the jurisdiction of the probate court for committing a felony may be held in the county jail pending trial if the case is designated by the court under section 2d of chapter XIIA of the probate code of 1939, 1939 PA 288, MCL 712A.2d, as a case in which the individual is to be tried in the same manner as an adult and the court has determined that there is probable cause to believe that the felony was committed and that there is probable cause to believe the individual committed that felony.
If a juvenile or individual less than 18 years of age is confined in the county jail under this subsection, the juvenile or individual less than 18 years of age must be held physically separate from adult prisoners.
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