Though it is not the only crucial thing for running your PC audio properly, still the answer to this question ‘Do I need to Install Realtek Audio Driver’, is definitely ‘Yes’!
It is because Realtek HD Audio Manager and its drivers usually act as a control panel for your audio adapters. When you have a Realtek HD Audio Drivers installed in your operating system, it automatically detects the devices like headphones/speakers/microphones, etc that are newly added to your computer in order to allow you to set up the audio setting as per your liking. Basically, Realtek HD Audio Drivers lets you manage the sound settings for Windows very effectively and smoothly.
Therefore, one can surely say that Realtek HD Audio Manager and its Drivers use for your Windows 10 operating system, is strongly recommended.