(a) except with the permission of the librarian no person shall handle or operate any record, film, sound equipment or viewing equipment other than a headset or volume control switch;
(b) no person shall listen to a record or to the sound-track of a film other than through a headset supplied by the librarian;
(c) no person shall switch on or keep switched on any volume control switch unless the headset affected thereby is worn over the ears; and
(d) except with the permission of the librarian no person shall on one occasion-
(i) listen to the playing of more than one record or composition, or the re-playing of any record or composition; or
(ii) view more than one film or view a film more than once.