gistfile1.js

function makeSquareWaveSound(hz, sampleRate) {
    var sampleRate = sampleRate || 44100;
    var data = new Array(sampleRate);
    var amplitude = sampleRate / hz / 2;
    for(var i = 0; i < data.length; i++){
        if(parseInt(i / amplitude % 2)) data[i] = '%00';
        else data[i] = '%FF';
    }
    var writeSize = function(size) {
        return [
            size & 255,
            (size >> 8) & 255, 
            (size >> 16) & 255, 
            (size >> 24) & 255
        ].map(function(e) {
            return '%' + ((e < 16) ? '0' : '') + e.toString(16);
        }).join('');
    };
    return [
        'data:audio/wav,',
        'RIFF',
        writeSize(data.length + 32),
        'WAVE', 
        'fmt%20',
        '%10%00%00%00',
        '%01%00%01%00',
        writeSize(sampleRate),
        writeSize(sampleRate),
        '%01%00%08%00data',
        writeSize(data.length)
    ].concat(data).join('');
}