window.addEventListener("load", (event) => {
    for (const elt of document.getElementsByClassName("mt-sound-play-button")) {
        elt.addEventListener("click", (event) => {
            const audioCtx = new (window.AudioContext || window.webkitAudioContext)();
            for (const freq of event.target.getAttribute("data-sound-info").split(",")) {
                const oscillator = audioCtx.createOscillator();
                oscillator.type = "sine";      // waveform: sine, square, sawtooth, triangle
                oscillator.frequency.value = parseInt(freq); // Hz
                oscillator.connect(audioCtx.destination);
                oscillator.start();
                oscillator.stop(audioCtx.currentTime + 2); // stop after 1 second
            }
        });
    }
});