Never buy hearing aids from street vendors or from radio and television advertisements, because these are not devices recognized as hearing aids but simple amplifiers.
Always take care to buy your hearing aid from a certified shop that has devices with a CE identification number and all the certificates required.
It is advisable, at your hearing aid appointments, to have a relative with you to better determine your needs and how much your hearing loss interferes with your daily life.
If your hearing aid becomes defective, contact your hearing care professional immediately. It is wise to keep a diary of your experiences while using the hearing aid to help your hearing care professional at your next visit.