The re-mastered edition of the audio track is not the original track from the film. The original track contained the actual sounds made by David Mooney during the filming. The baby sounds came from his performance and not canned baby sounds. The original track must have been lost and later baby sounds were added.
It took about a year for writer Abe Polsky to convince Ted Post to direct the film; Post was reluctant to make the movie because he found the dark premise to be too negative.
This was Tod Andrews's final film before his death on November 7, 1972 at the age of 57. He died seven months before the film's release.