# Automated Personalized Loudness Control for Multi-Track Recordings
## 1 Introduction  
Music mixing is an intricate process that transforms multi-track material--recorded, sampled or synthesized--into a cohesive multi-channel format [1]. This process is not merely technical; it significantly influences the emotional connection between the music and its audience. A well-executed mix can profoundly affect the experience of the listener, emphasizing the aristry in sound engineering. The field of music mixing is experiencing significant changes due to the introduction of automated solutions. The goal of incorporating automation in music mixing is to mimic or assist the complex and artistic process that has traditionally relied on the skill of a professional. This particular expertise is essential for modifying the dynamics, spatial characteristics, timbre and pitch in multi-track recordings. The alteration of these components involves a sequence of procedural stages that employ both linear and nonlinear processes to achieve the desired auditory outcome [2]. The following steps can be outlined:  
* Gain Adjustment--this initial stage in mixing involves setting the overall volume levels of different tracks to obtain a well-balanced mix, preventing any single element from dominating the others;
* Equalization (EQ)--this is the deliberate adjustment of specific frequency ranges to improve the clarity and balance of the mix. This technique ensures that each instrument or voice has its own distinct sonic presence;* Panning--this involves manipulating the stereo position of each track to create a sense of spatial depth in the mix. This technique enhances the listening experience by replicating the placement of sounds in a three-dimensional space, resulting in a more immersive effect;
* Dynamic Range Compression (DRC)--this is a technique that reduces the difference between the softest and loudest sounds in audio signals. It accomplishes this by amplifying soft sounds and attenuating loud sounds, resulting in a more uniform volume level across the mix. This technique is essential for preserving energy and guaranteeing the audible presence of all components;
* Artificial reverberation--this is the process of incorporating reverb effects to imitate different acoustic settings, ranging from compact chambers to large venues. This technique enhances the sonic dimension and ambiance of the audio mix. Loudness, in the realm of audio engineering, refers to the subjective perception of the power or magnitude of a sound. Unlike objective measures of sound pressure like decibels (dB), loudness is a subjective sense that is affected by frequency and impacted by the unique characteristics of the human auditory system [3]. The intricacy of perceiving loudness has resulted in the creation of multiple standards and models to accurately and meaningfully measure it, such as the International Telecommunication Union's ITU-R BS.1770 [4] and the European Broadcasting Union's EBU R128 recommendation [5]. Loudness is not solely determined by amplitude, but rather it is a psycho-acoustic characteristic that reflects how humans perceive the intensity of sound. The perception of sound is influenced by various elements, including the frequency content, duration and the surrounding context in which it is heard [6]. The challenge of audio mixing is to achieve a harmonic and enjoyable listening experience by balancing the perceptions of diverse audio tracks. Gain adjustment in the mixing process is indeed grounded on loudness measurements, tailored to the auditory perception of the engineer. This phase is crucial in the mixing process, if this step is not executed correctly, it can adversely impact all subsequent stages in the mixing workflow. Loudness management guarantees that the ultimate blend achieves a perceived volume that aligns with industry norms and listener expectations, while preserving the dynamic range and sound quality. The volume of each track in a mix is a crucial factor that can greatly impact the overall sound and clarity of the finished result.