audiocontext Samplerate returning null after being read 8 times

Question

I have made a function to produce a drum sound how ever after being called 4 times it stops working with the error:

TypeError: null is not an object (evaluating 'audioCtx.sampleRate') Showing in the console.

What's wrong with this function? My code is:

drum = function(){
    var audioCtx = new (window.AudioContext || window.webkitAudioContext)();
    var frameCount = audioCtx.sampleRate/20
    var myArrayBuffer = audioCtx.createBuffer(1, frameCount, audioCtx.sampleRate);
    var nowBuffering = myArrayBuffer.getChannelData(0);
    for (var i = 0; i < frameCount; i++) {
        nowBuffering[i] =Math.sin(i**(1/1.8)/4)
    }

    var source = audioCtx.createBufferSource();
    source.buffer = myArrayBuffer; source.connect(audioCtx.destination);
    source.start();
}

Answer 1

Your audioCtx assignment should be moved outside of drum(), as it will get called every time, eventually throwing an exception since you can't create more than 6 audio contexts in a document.