Dyson vacuums are designed with a focus on performance and user experience, and they generally strive to reduce noise levels while maintaining powerful suction capabilities. The specific noise level can vary depending on the model and its intended use. For example, many of Dyson's upright and cordless models typically produce noise levels measured in decibels ranging from about 60 to 80 dB, which is comparable to the noise levels of a normal conversation to that of a busy street.
It is important to note that advanced engineering techniques, such as the use of acoustic materials and optimally designed motors, help in minimizing the noise during operation. Additionally, some models may have features that allow for quieter operation modes. To determine the exact noise level for a specific vacuum model, it may be helpful to check the product specifications on dyson.com where detailed information is often provided.