The legislative history of the exemption is explicit that the exemption applies only to an employee who is employed ``primarily'' as an announcer, news editor, or chief engineer. Thus the Senate Report states: ``The exemption is specifically limited to those employees who are employed primarily in the named occupations * * *'' (S. Rept. 145, 87th Cong., 1st sess., p. 37). No specific rule can be established for determining whether in any given case an employee is employed ``primarily'' in the named occupations. Generally, however, where an employee spends more than half of the hours he works in a workweek in a named occupation, he will be considered to be primarily employed in such occupation during that workweek. The answer will necessarily depend upon the facts in each case.