How to change sound volume using webAudio api gain property

A quick function to adjust html5 web audio gain value or "audio volume"

sound gain value is controlled by creating a gain node and setting it's gain value 0-1

where 0 is the lowest value 1 is the maximum gain value 

let sound = function sound(url, params) {

    // params

    let loop = params.loop;

    // make a context

    let audioContext = new (window.AudioContext || window.webkitAudioContext)();

    let source = audioContext.createBufferSource();

    let gainNode = audioContext.createGain()

        gainNode.gain.value = 0.05 // sound percentage

    let request = new XMLHttpRequest();

request.open('GET', url, true);

    request.responseType = 'arraybuffer';

    request.onload = function() {

            audioContext.decodeAudioData(request.response, function(buffer) {

            source.buffer = buffer;

            

            gainNode.connect(audioContext.destination)

            source.connect(gainNode)

            source.loop = loop;

            source.start(0);

        }, (e) => {

            throw new Error('Audio error! ', e);

        });

    }

    request.send();

}