MacOS – Use macbook inbuilt microphone with audio going through mic-less earphones

You cannot directly plug your headphones into the Audio Input jack and have it work, because, the microphone/button signal rides on the third ring, and the audio input jack only connects the first two. You have to have specially designed hardware to connect to that third ring. This is currently achieved via the Headphone/Audio Output ports of devices.

Only the iPhone/iPod Touch/iPad, 2010 MacBook Pros, and the modern body (smaller height) Mac Minis are the only pieces of hardware I am aware that do. Anything older will not support the microphone/button/volume buttons at all.

I am not sure the iPhone headphones with the built-in microphone will work on older MacBooks, since I believe they do require a headphone jack capable of sending the microphone input. Headphone jacks on MacBooks shipped after the iPhone was introduced all have that capability.

As fas as microphone recommendations, the following two seem to be regarded as very good by different sources I trust, such as the Equipment Guide that 5by5's Dan Benjamin writes every year:

• For beginners: Plantronics .Audio 655 USB Multimedia Headset
• For pros: Heil PR40 Dynamic Microphone

Hope this helps.