To record digital audio you will need a computer to process the audio as well as the effects you will use on the recorded sounds. Most large commercial studios use Macintosh computers for this. However, you can use any type of computer, including a PC, with software specifically designed for audio processing, such as Pro Tools and Emagic Logic. The more powerful the computer, the quicker and easier it will be to edit and play multiple tracks at the same time. To get the audio onto your hard drive, you will also need an audio interface. These are connected through an input such as a Firewire or USB port, or can be installed in an open bay of a desktop computer. These interfaces can be simple stereo inputs or more advanced units that can record multiple tracks simultaneously; they are limited only by the computer's processing power.
To record the audio, a mixer must be used to set the levels so the sounds you record are of high quality. The use of a digital mixer or software-based mixers is essential in the recording and final mixing of audio in a digital studio. Some hardware-based audio production suites include a mixer to connect to your computer, while others use a software program that allows you to set levels on your computer screen. This software emulates the look of a mixer on the screen as an easy way to visualize the process of mixing. The mixer can transform the analog audio signal to a digital signal for use with your software. Software-based digital audio programs use a sound card to convert the signal for use with a graphical mixer in the same manner.
The most important aspect of digital audio production is the software you use because this is what processes the audio and allows you to mix it to the right levels. There are many programs available, but Pro Tools is the industry standard. Pro Tools was released in the early '90s and includes hardware as well as software for digital audio production. Emagic Logic and Sony Vegas are other software suites that allow you to manipulate digital audio in a similar manner, but work with many different types of hardware interfaces, including digital mixers and USB and Firewire sound cards.