Check if two words rhyme

rhyme.js

//download dictionary from https://svn.code.sf.net/p/cmusphinx/code/trunk/cmudict/cmudict.0.7a
//dictionary format: ['RHYME', 'R AY1 M']

const rhymeDict = [];

//despite the size of the file, this parses reasonably quickly
function populateRhymeDict() {
  fetch('cmudict.0.7a.txt')
    .then(response => response.text())
    .then(data => {
      dictLines = data.split('\n');
      for (let i = 55; i < dictLines.length; i++) {
        let content = dictLines[i].split('  ');
        rhymeDict[content[0]] = content[1];
      }
      dictReady = true;
    });
}

function arraySegmentsEqual(arr1, arr2, i1, i2) {
  if (arr1.length - i1 != arr2.length - i2) { return false; } //must have same amount
  for (let i = 0; i < arr1.length - i1; i++) {
    if (arr1[i1 + i] !== arr2[i2 + i]) { return false; }
  }
  return true;
}

function checkRhyme(a, b) {
  let phonA = rhymeDict[a.toUpperCase()];
  let phonB = rhymeDict[b.toUpperCase()];
  if (phonA == undefined || phonB == undefined) { return false; }
  
  //find first point of emphasis
  let syllA = phonA.split(' ');
  let syllB = phonB.split(' ');
  let emphIndexA = -1;
  let emphIndexB = -1;
  for (let i = 0; i < syllA.length; i++) {
    if (syllA[i].indexOf('1') > -1) { emphIndexA = i; break; }
  }
  for (let i = 0; i < syllB.length; i++) {
    if (syllB[i].indexOf('1') > -1) { emphIndexB = i; break; }
  }

  if (arraySegmentsEqual(syllA, syllB, emphIndexA, emphIndexB)) { return true; }
  return false;
}