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js实现声学测试

2026-03-01 15:06:37JavaScript

使用Web Audio API进行基础声学测试

Web Audio API是浏览器内置的音频处理接口，适合实现频率响应、音量检测等基础声学测试功能。

初始化音频上下文
创建AudioContext对象并获取用户麦克风权限：

const audioContext = new (window.AudioContext || window.webkitAudioContext)();
navigator.mediaDevices.getUserMedia({ audio: true })
  .then(stream => {
    const microphone = audioContext.createMediaStreamSource(stream);
    microphone.connect(audioContext.destination);
  });

频率分析
使用AnalyserNode获取实时频率数据：

const analyser = audioContext.createAnalyser();
analyser.fftSize = 2048;
microphone.connect(analyser);

const bufferLength = analyser.frequencyBinCount;
const dataArray = new Uint8Array(bufferLength);
analyser.getByteFrequencyData(dataArray); // 更新数据到dataArray

实现音量检测

通过计算信号均方根（RMS）值检测音量：

const processor = audioContext.createScriptProcessor(2048, 1, 1);
microphone.connect(processor);

processor.onaudioprocess = event => {
  const input = event.inputBuffer.getChannelData(0);
  let sum = 0;
  for (let i = 0; i < input.length; i++) {
    sum += input[i] * input[i];
  }
  const rms = Math.sqrt(sum / input.length);
  console.log(`当前音量: ${rms}`);
};

生成测试音信号

使用OscillatorNode生成特定频率的测试音：

const oscillator = audioContext.createOscillator();
oscillator.type = 'sine'; // 正弦波
oscillator.frequency.value = 1000; // 1kHz频率
oscillator.connect(audioContext.destination);
oscillator.start();

校准与可视化

结合Canvas绘制实时频谱图：

js实现声学测试

const canvas = document.getElementById('visualizer');
const ctx = canvas.getContext('2d');

function draw() {
  requestAnimationFrame(draw);
  analyser.getByteFrequencyData(dataArray);

  ctx.clearRect(0, 0, canvas.width, canvas.height);
  dataArray.forEach((value, i) => {
    ctx.fillRect(i * 2, canvas.height - value, 2, value);
  });
}
draw();