Perspiration and humidity can affect the sensitive electronics inside modern hearing aids. Research by the Technical University of Denmark and WS Audiology shows how corrosion develops and why it can also impair the performance of lithium-ion batteries.
Hearing aids accompany their users throughout the day. They are exposed to changing temperatures, high humidity and direct skin contact. Moisture combined with salts from perspiration can promote corrosion of electronic components and contacts.
Research conducted through a collaboration between the Technical University of Denmark (DTU) and WS Audiology identified chloride ions, high humidity, soldering flux residues and inadequate protective coatings as factors contributing to corrosion damage. Increasing miniaturisation and the higher operating voltage of rechargeable hearing aids place additional demands on the protection of their electronics. DTU research
Corrosion affects more than contacts and circuit boards. Damage to components responsible for charging and power management can also alter the electrical demands placed on the battery.
A study published in the Journal of Power Sources in 2025 examined failed lithium-ion batteries from hearing aids and complemented the analysis with laboratory tests. The results show that high discharge currents and deep discharges can accelerate battery degradation. Corrosion-related electronic faults are therefore also relevant to battery reliability. Study on battery degradation
High-quality protective coatings help shield sensitive components from moisture and contaminants. The DTU research found that the vapour-deposited coatings tested provided significantly better corrosion protection than the liquid-applied reference coating. These findings highlight the importance of selecting suitable coatings and ensuring their quality. DTU research
Moisture can also be present as water vapour. If humid air inside a hearing aid cools sufficiently, condensation can form. The determining factor is whether the temperature falls below the dew point. Understanding the dew point
Suitable drying solutions can therefore be a useful part of daily care. flow-med offers a range of devices, including models that use airflow without additional heat and are also designed for rechargeable hearing aids. Depending on the model, drying and charging can take place together. Information on flow-med drying solutions
The appropriate solution for each hearing aid and charging station should be selected in accordance with the manufacturers’ instructions. Your hearing care professional can help you incorporate suitable care into your daily routine.
