The device that translates digital signals into audio signals for playback is called a digital-to-analog converter (DAC). DACs are crucial in various electronic devices, such as computers, smartphones, and audio equipment, enabling the playback of digital audio files. They convert binary data representing sound into analog signals that can be amplified and heard through speakers or headphones. The quality of a DAC can significantly affect audio fidelity, impacting sound clarity and realism during playback, which is crucial for audiophiles and sound engineering.