code: function onVolumeChange() {
  		const volumePercentage = media.muted ? 0 : media.volume;
  		const isMuted = !volumePercentage;
  
  		$(self.volume, { 'aria-valuenow': volumePercentage, 'aria-valuemin': 0, 'aria-valuemax': 1 });
  
  		const dirIsInline = /^(ltr|rtl)$/i.test(volumeDir);
  		const axisProp = dirIsInline ? 'width' : 'height';
  
  		self.volumeMeter.style[axisProp] = `${volumePercentage * 100}%`;
  
  		$(self.mute, { 'aria-label': isMuted ? lang.unmute || 'unmute' : lang.mute || 'mute' });
  		$(self.muteSymbol, { 'aria-hidden': isMuted });
  		$(self.unmuteSymbol, { 'aria-hidden': !isMuted });
  	}
docs: when the volume changes