Do webcams have built-In microphones?

Most models are equipped with microphones. However, check the specifications before you buy if this is important to you. Some high end "streamer" or premium 4k models may omit a microphone as the assumption here is that such users looking for such high grade video will also be using a separate high end microphone for their broadcast. There are some budget models also omit microphones. If in doubt, check the specification.

• A typical webcam with microphone uses omnidirectional microphones to capture voice.
• High-tech PC cameras with microphone often utilise dual microphones with active noise cancellation. 
• Digital noise cancelling filters eliminate echoes and fan noise, improving speech clarity without the need for a headset.