There are certain situations where it is not recommended to use noise-cancelling headphones. Some examples include: 1. Driving: Wearing noise-cancelling headphones while driving can be dangerous. It can reduce your ability to hear car horns or emergency sirens. 2. Walking or cycling in busy areas: It is essential to be aware of your surroundings when walking or cycling. Noise-cancelling headphones can reduce your awareness of external sounds. 3. Performing outdoor activities: Hiking, camping, or climbing requires awareness of your surroundings and external sounds. Which can be reduced by using noise-cancelling headphones. It is better to use regular headphones or earplugs that do not block out ambient noise. 4. With infants or young children: Listening to music at high volumes can harm the developing ears of young children. It is better to avoid using noise-cancelling headphones around them instead of regular headphones with a low volume or no headphones.