Every injured employee or his representative shall, immediately on the occurrence of any accident or as soon thereafter as practicable, give or cause to be given to the employer, his agent, representative, or foreman, or the immediate superior of the injured employee a notice of the accident. This notice shall be given by the employee either in person or by his representative, and until such notice is given the employee shall not be entitled to any physician's fees nor to any compensation which may have accrued under the terms of this chapter prior to the giving of such notice. In the event that, within 30 days after the accident, neither the employee nor his representative has given a notice in person to the employer, his agent, representative, or foreman, or to the immediate superior of the injured employee, a written notice must be given. This written notice will not be required where an injured employee or his representative has given notice in person to the employer, his agent, representative, or foreman, or to the immediate superior of the injured employee. No compensation will be payable unless such notice, either oral or written, is given within 30 days after the occurrence of an accident or within 30 days after death resulting from an accident unless it can be shown that the employee had been prevented from doing so by reason of physical or mental incapacity, or by fraud or deceit, or that the employer, his agent, representative, or foreman, or the immediate superior of the injured employee had knowledge of the accident, or unless a reasonable excuse is made to the satisfaction of the board for not giving such notice and it is reasonably proved to the satisfaction of the board that the employer had not been prejudiced thereby.