What does a sound card convert from a microphone into computer data?

A sound card is a critical component in managing audio input and output for a computer system. When a microphone captures sound, it does so in the form of analog signals, which are continuous waves representing sound waves. These analog signals must be converted into a format that a computer can process, which is typically digital data.

The sound card facilitates this conversion process by taking the varying voltages from the microphone, which represent the audio signal, and translating them into a binary format (1s and 0s) that the computer can understand and manipulate. This digital representation enables the computer to store, process, and playback the sound efficiently.

In terms of the other options, digital signals refer to the result of the conversion process and not the initial form captured by the microphone, while video signals pertain to visual data and power signals are concerned with electrical power rather than audio data processing. Thus, the primary role of the sound card in relation to a microphone is to convert analog signals into digital format, making "analog signals" the correct answer.