While both provide world-class noise cancelling, high-quality audio performance and a comfortable fit, there are a few key differences. QuietComfort 45 headphones have 2 modes of noise cancellation – Quiet Mode and Aware Mode. Bose Headphones 700 offer more customisation, with 11 levels of noise cancelling. Bose Headphones 700 also offer the convenience of capacitive touch controls and hands-free access to Amazon Alexa, Google Assistant, and your phone’s native voice assistant, like Siri. For battery life, you’ll enjoy up to 22 hours with QuietComfort 45 headphones and up to 20 hours with Bose Headphones 700