Lydsignal

Lydsignal, written in lowercase as lydsignal, is a term used in Scandinavian languages, and more broadly in electronics, to denote an audio signal—a time-varying electrical quantity that conveys sound information, or its acoustic counterpart as a pressure wave.

In practice, a lydsignal may be analog, where the voltage or pressure changes continuously, or digital, where the signal is represented by discrete samples after sampling and encoding.

Common characteristics include amplitude (loudness), frequency content, and timing. When measured, key metrics include signal-to-noise ratio, dynamic range, and total harmonic distortion.

Formats and interfaces: analog signals travel via microphone or line-level connections; digital signals use interfaces such as S/PDIF, AES/EBU, or USB, and can be stored as WAV, AIFF, MP3, AAC, etc.

Applications: musical recording, broadcasting, live sound reinforcement, telecommunications, consumer audio devices, alarms, and signaling.

In Scandinavian usage the term is common in education and industry, and is closely allied to the broader concept of audio engineering and signal processing.