Double-click the desktop icon to launch your preferred digital audio workstation, for example Garageband or Pro Tools.
Open the session containing the rap vocals. The specific method for doing this varies according to which program you use, but you typically do this by clicking "File," "Open" and "Recent." If you didn't record the vocals using a digital audio workstation, you need to import the audio files into a new session. Again, the process varies but typically you click "File," "Import" and select from the drop-down menu the audio files you need.
Click on the first vocal to be equalized. This assigns subsequent edits and mix tweaks to that audio, rather than the entire mix.
Launch your preferred equalization tool. Typical digital audio workstations have an array of equalizer tools, each with parameters and controls generically based on real-world equalizers. The method for launching an equalizer varies between programs, but the equalizer is usually located in the "Effects" or "Tools" menu. Once you launch the equalizer, a new window will open with equalization control parameters including an array of virtual slider dials and a grid interface.
Hit "Play" so you can hear your modifications in real-time.
Drag the mixer dial or dials for the 200 to 400 KHz range. The equalizer divides the audio into frequency bands. By moving a slider dial up, you increase the volume of that particular frequency band relative to the others. Because rap vocal delivery is similar to spoken word, begin in the mid frequency range. This enhances the most common naturally occurring frequencies and adds "body" to the vocal.
Click "Bypass" to hear the audio without EQ.
Drag the mixer dial for 3 KHz up. Boosting this frequency adds clarity, which will make the rap vocals more "punchy." Because rap lacks the projection of full-on singing, you should aim to equalize the vocals so they cut through the mix. Typical rap music is bass-heavy, meaning the vocals can easily become "buried" in the mix. Enhancing the high frequencies mitigates this.
Click "Bypass" and then make as many small tweaks as necessary until you're happy with the balance. For example, if the vocals sound too "tinny," reduce the top-most frequencies a little. Equalization is a fine balancing-act. A tweak to one frequency range can make another frequency range sound too loud or too quiet.