I wrote a function that creates mp3 files from an array of buffers of audio content with all of them concatenated.

const generateAudioFile = async ({ fileName, audioContent }) => {
  const writeFile = util.promisify(fs.writeFile);
  await writeFile(
    path.join(__dirname, 'output', `${fileName}.mp3`),
    Buffer.concat(audioContent),
    'binary'
  );
};

While it does what it is supposed to do, there are no gaps between each audio content, and this is what I am trying to fix. I have tried padding some allocated space after each file like so but it does not do the job:

Buffer.concat([...audioContent.map(ac => Buffer.concat([ac, Buffer.alloc(10000)]))])

How can I add some silence between each audio buffer?