got an answer from @lassekorsgaard
let currentSongIndex = 0
let totalSongs = 6
let canPlay = true
let timer = null
function playSong() {
if (timer) {
clearTimeout(timer)
timer = null
}
songs[currentSongIndex].play()
timer = setTimeout(nextSong, 5000)
}
function nextSong() {
if (currentSongIndex < totalSongs) {
currentSongIndex++
}else{
currentSongIndex = 0
}
playSong()
}
function speechResult() {
var resultArray = myRec.resultString.split(' ').pop()
if (resultArray.indexOf('') > -1 && canPlay) {
nextSong()
}
}