At top is fairly deluxe polycarbonate spork by Light My Fire. It comes in assorted colors, and looks like it do just about anything needed in the line of feeding.
Below it is the Fox40 mini whistle. I've taken a sudden interest in whistles since my mother fell down in her own back yard this week, and spent two hours calling for help before a neighbor helped her back inside. Bottom line: she suffered a minor asymptomatic heart attack. In older people, a heart attack can produce loss of balance, but no pain. She's in the hospital right now, but doing well.
Anyway, I've learned that a whistle will produce more noise than a person can make by just yelling. The Fox40 line doesn't use any sort of cork ball running around inside. It produces a much higher-pitched screech than the warble from a regular whistle. A whistle is highly recommended for any outdoor or survival gear, or in this case, for my mother.
Both items are in the $3-$4 price range at any decent camping supply store.