single-line-delay.js

const inputSignal = readSignalFromSomewhere()
const outputSignal = new Array(inputSignal.length)
const delayInSamples = 44100
const delayBuffer = new Array(delayInSamples)
const decay = 0.5
let pointer = 0

inputSignal.forEach(sample => {
    const previousSample = delayBuffer[pointer % delayInSamples]
    delayBuffer[pointer] = sample + previousSample * decay
    
    //make sure out buffer is indeed circular
    pointer++
    if (pointer > delayInSamples){
        pointer = 0;
    }
    outputSignal.push(sample + previousSample)
})