Although the diphthong /ɔɪ/ is the rarest of all English vowels, occurring in only 794 words in the Mitton dictionary, the /i/ versus /ɔɪ/ contrast still yields over twice as many pairs as the /i/ versus /ʊə/ contrast.
The vowel /i/ displays its usual range of spellings, including the letter names B, C, G and T and the musical note name ti. The /ɔɪ/ diphthong is spelled <oi> or <oy> except in the proper names Fowey and Neuss.
Interesting pairs include:
ceiling soiling
Easter oyster
litre loiter
Mean density value is 2.7% in spite of the great disparity in frequency. The 98 pairs make 59 semantic distinctions, giving a semantic loading of 60%.
alee alloy B boy B's boys B buoy B's buoys be boy be buoy being buoying bead buoyed bee boy bees boys bee buoy bees buoys C soy ceiling soiling Ealing oiling Easter oyster Easters oysters eel oil eels oils Ely oily feast foist feasted foisted feasting foisting feasts foists fee Fowey feeble foible feel foil feeling foiling feels foils field foiled G joy G's joys gee joy gene join genes joins Gina joiner green groin greens groins green groyne greens groynes jean join jeans joins keel coil keeled coiled keeling coiling keels coils keen coign keens coigns keen coin keened coined keener coiner keening coining keens coins keen quoin keens quoins key coy knees noise leads Lloyd's lean loin leans loins Leeds Lloyd's litre loiter litres loiters meal moil meals moils Nice Neuss niece Neuss P's poise peas poise pease poise pees poise plea ploy pleas ploys please ploys quay coy re Roy sea soy seal soil sealed soiled sealing soiling seals soils see soy T toy T's toys tea toy teas toys teal toil tease toys teashop toyshop teashops toyshops tee toy teed toyed teeing toying tees toys ti toy tree troy veal voileGeographical: Outside English-speaking countries, most visitors are from Hong Kong, Turkey, Jordan, Saudi Arabia, Poland, Libya, South Korea, Yemen, Ecuador, Indonesia, Malaysia, India Syria and Spain. Average 13 visitors per month.
John Higgins, Shaftesbury, January 2011.