My Philips Sonicare toothbrush makes a loud noise If your Philips Sonicare toothbrush makes a loud noise when you switch it on, there might be a very simple solution. Remove the plastic travel cap You may have forgotten to remove the transparent plastic travel cap from the brush head before turning the toothbrush on. Having Issues with your Philips Sonicare product? Try our troubleshooting & warranty replacement self-service tool. Start Warranty Exchange Service