How to Disable Onboard Sound. This Article teaches you how to disable entirely your Windows or Mac computer’s built-in speakers (also known as “onboard sound”). You can do this from within your device’s settings on a Windows computer, while disabling sound on a Mac will require you to download an audio-moderating application called Soundflower. There are several options for disabling or adjusting your sound, depending on what you want to accomplish. You may want to disable sounds from a program, the internal speaker, a modem, sound from the speakers/headphones, or disable an onboard sound card. For more information on these options, review the options below if they apply to what you’re trying to disable. When the audio fidelity of your built-in sound card doesn’t deliver for the requirements of your business, a new sound card soon becomes a worthy addition to your motherboard’s precious real estate. However, resource conflicts or conflicting software designed to operate your system’s built-in sound card may interfere with the proper functioning of your new sound card, so your best bet is to shut down your computer’s built-in sound card and let your new processor do its job.