Information Technology IT – 11 Video and audio editing | e-Consult

Purpose of Audio Compression: The purpose of audio compression is to reduce the dynamic range of an audio signal. This means making the quiet parts louder and the loud parts quieter, resulting in a more consistent overall loudness. It's used to improve the intelligibility of speech, enhance the impact of music, and make audio more suitable for broadcast or playback on devices with limited dynamic range.

Types of Compression:

• Dynamic Range Compression: This is the most common type of audio compression. It uses a threshold level. When the audio signal exceeds the threshold, the compressor reduces the gain of the signal. This reduces the difference between the loudest and quietest parts of the audio. Parameters like threshold, ratio, attack time, and release time control the compression's behavior.
• Loudness Normalization: This is a more sophisticated form of compression that aims to make the audio sound the same loudness as other audio content. It uses algorithms (like ITU-R BS.1770) to analyze the audio and apply compression to achieve a target loudness level. This is commonly used for broadcast and streaming platforms.

Drawbacks of Excessive Compression: Excessive compression can lead to a number of undesirable effects:

• Loss of Dynamics: Over-compression removes the natural variation in loudness, making the audio sound flat and lifeless.
• Pumping/Breathing: If the attack and release times are set incorrectly, compression can create an unnatural "pumping" or "breathing" effect.
• Distortion: Excessive compression can cause distortion, especially at high levels.