Lawyers for Egypt's ousted president and his co-defendants walked out of court on Sunday to protest the soundproof glass cage in which defendants are held during proceedings, state TV reported.

It said judge Shaaban el-Shamy ordered a recess after the lawyers left the hearing, the first in a case in which Morsi and 35 others are facing charges of conspiring with foreign groups and undermining national security.

El-Shamy, who later ordered the trial adjourned until Feb. 23, was quoted by the private CBC TV network as telling the lawyers that the trial would proceed without them. It also reported that Morsi shouted at the start of the trial that he could not hear the proceedings.

El-Shamy sent technicians to inspect the cage to verify Morsi's claim, CBC said. The judge then ordered the volume raised to allow Morsi to better hear. The defense lawyers remained unsatisfied and walked out.

The cage was introduced after Morsi and his co-defendants interrupted the proceedings of other court cases by talking over the judge and chanting slogans. The cage is fitted to give the judge sole control over whether the defendants can be heard or not when speaking.

Morsi was ousted by the military following millions-strong protests demanding his step down after just one year in power. He, together with leaders of his Muslim Brotherhood, now face a multitude of trials on a range of charges, some of which carry the death penalty.