CAIRO — Mohamed Morsi, the deposed Egyptian president, appeared in public on Tuesday for the second time since his detention after the military takeover in July, this time locked in a soundproof glass cage as the defendant at a criminal trial.

The installation of the cage, a novelty in Egyptian courts, underscored the extent of the effort by the new government to silence the former president and his fellow defendants, about 20 fellow leaders of the Muslim Brotherhood. It dominated the courtroom debate, with lawyers for the defendants arguing that it deprived the accused of their right to hear or participate in their own trial and supporters of the government crediting the soundproof barrier with preserving order in the court.

“The glass cage was the hero of today’s trial,” Egyptian state television declared.

For his first appearance, at another trial in the same makeshift courtroom in November, Mr. Morsi insisted on wearing a dark business suit instead of the customary white prison jumpsuit, and then stole the spotlight by disrupting the proceeding. He shouted from the cage, which was not soundproof, that he was the duly elected president and the victim of a coup, and his fellow defendants shut down the trial by chanting against military rule.

Appearing on Tuesday in ordinary prison dress, Mr. Morsi passed his cage angrily and bided his time for a chance to speak again. When the judge turned on the microphone so that Mr. Morsi could acknowledge his presence, he shouted out, “I am the president of the republic, and I’ve been here since 7 in the morning sitting in this dump,” according to an account on a Brotherhood website that was confirmed by people who had been present.