Cosby was the first celebrity tried and convicted in the #MeToo era. He insists the sexual encounter with a young woman seeking career advice was consensual.
A jury last year found Cosby drugged and molested her at his suburban Philadelphia estate in 2004.
Defense lawyers contend the trial judge erred in letting five other accusers testify to bolster the prosecution’s case.
The three-judge Superior Court panel includes two women jurists. The panel is not expected to rule for several months.
The decision will be closely watched by both sexual assault victims and lawyers for Harvey Weinstein and other high-profile men accused of similar misconduct.