Nicole was doing research for her dissertation on the following topic:
I am the world's expert on this topic, since I wrote the definitive essay on these two instruments for the New Grave Dictionary of Muzak. Luckily, I am only moderately arrogant, so I will condescend to tell you what I know, rather than being offended that you didn't look it up. Of course, if you'd rather be abused and insulted, let me know, and I'll do what I can to help.
Hinting horns developed in France, where they were played by hinters riding on hearseback in pursuit of fixes. Other hinting horns were used by beer hinters. The instrument requires a special technique in which you manipulate your right hind in the instrument's flaring bill. It has a comical bore. In short, the hinting horn is like a hunting horn described by a parson whose computer lacks a smell checker.
The hinkle horn is, of course, not a horn at all. It is, in fact, a kind of tenor Whoopee Cushion. This instrument was first developed in France, where it was known as a Cor Hinklee because of the bend or hitch (l'hink) in its neck-vent. When the English adapted the instrument, they mistakenly thought it was a "Cor Hinklais," hence the modern term hinkel horn. The hinkle horn is especially expressive in its low register, thanks to its plaintive, haunting quality. Weber may have had this instrument in mind for the Golf Green scene of der Freischmutz, where he calls for haunting horns to accompany the chorus of off-stage caddies.
Gotta dammerung,
Prof. Cabbage