μ-law is a method used in signal processing to compress audio signals. It works by applying a logarithmic scale to the amplitude of the audio, which helps to reduce the dynamic range. This means that quieter sounds are amplified more than louder sounds, making it easier to transmit and store audio data without losing important details. This technique is commonly used in telecommunications and digital audio systems, particularly in PCM (Pulse Code Modulation) formats. By using μ-law, systems can achieve better sound quality at lower bit rates, making it an efficient choice for voice transmission and other audio applications.