{
  "CLOSE":{
    "FRONT":["i","y"],
    "CENTRAL":["ɨ","ʉ"],
    "BACK":["ɯ","u"]
  },
  "NEAR_CLOSE":{
    "NEAR_FRONT":["ɪ","ʏ"],
    "NEAR_BACK": [null,"ʊ"]
  },
  "CLOSE_MID":{
    "FRONT":["e","ø"],
    "CENTRAL":["ɘ","ɵ"],
    "BACK":["ɤ","o"]
  },
  "MID":{
    "CENTRAL":["ə",null]
  },  
  "OPEN_MID":{
    "FRONT":["ɛ","œ"],
    "CENTRAL":["ɜ","ɞ"],
    "BACK":["ʌ","ɔ"]
  },
  "NEAR_OPEN":{
    "FRONT":["æ",null],
    "CENTRAL":["ɐ",null]
  },
  "OPEN":{
    "FRONT":["a","ɶ"],
    "BACK":["ɑ","ɒ"]
  }      
}