Noizio is an app that will drown out the noise of the street and allow you to concentrate on the work at hand, increasing your productivity. On the other hand, it can also set the mood for a romantic evening or lull you to sleep, ensuring that you will dream soundly all night long. An ambient sound equalizer app for creating a mixture of ambient sounds available for macOS.
Virtual Audio Cable - Ever wanted to record your speaker output? (loopback) This is for you.
Noisli - Noisli is a fantastic background noise and color generator for working and relaxing. Online soothing ambient sounds like White noise, Rain and Coffee Shop.
Loopback by RogueAmoeba - Get all the power of a high-end studio mixing board, right inside your Mac!
A Soft Murmur - Ambient sounds to wash away distraction.
JACK Audio Connection Kit - JACK Audio Connection Kit|Home
MyNoise - Custom shaped online noise machines. Many Many generic sounds