Judge Balley Aldrich '28 tentatively admitteed into evidence yesterday a tape recording of the Jan. 1954 hearing at which Leon J. Kamin '48 refused to discuss former Communist associates. His decision followed a day-long battle by the defense.

The portion of the tape played to Judge Aldrich yesterday seemed directly to contradict Senator Joseph R. McCarthy's testimony that Kamin was present in the hearing room when he discussed the purposes for which Kamin had been called. The tape included a phrase not recorded in the transcript: After McCarthy had explained the hearing's purpose and said Kamin would be the first witness, a voice said, "I believe Mr. Kamin is in the side room."

Aldrich accepted the recordings after defense counsel Calvin P. Bartlett asserted that the tapes would show differences from the printed transcript. But he has not finally ruled out government objections. He added, after defense and government lawyers agreed, that he would listen to them in private to save time.

Kamin May Testify

The trial resumes at 10 a.m. today, and the defense will proceed with the presenting of witnesses. Kamin has not yet testified but may be called to the stand today.

In another development, S. S. Stevens, Director of the University Psychology Laboratories, testified that Kamin's summer work on a radar project in 1945 involved no contact with classified government information.

Stevens, former co-director of the project, said Kamin was one of a group of "guinea pigs" in an experiment on how efficiently a group could operate a radar information room aboard Navy vessels. He said they were "in no sense research, scientists" and had no contact, to his knowledge, with the "classified aspects of radar."

Government attorney John M. Harrington, Jr. '43, objected strongly to the admission of the tape recordings after the testimony of John Molloy, program director of Station WNAC, which made the tapes, and Norman F. Ramsey, Jr., professor of Physics, who paid for them. Aldrich said he agreed partially with the objections.

Harrington declared the recordings were made by a person whose identity could not be determined.