FileAudioFormatter.php

<?php

namespace Drupal\file\Plugin\Field\FieldFormatter;

use Drupal\Core\Field\Attribute\FieldFormatter;
use Drupal\Core\StringTranslation\TranslatableMarkup;

/**
 * Plugin implementation of the 'file_audio' formatter.
 */
class FileAudioFormatter extends FileMediaFormatterBase {
  
  /**
   * {@inheritdoc}
   */
  public static function getMediaType() {
    return 'audio';
  }

}