Sound Adjustment is a lightweight add-on for Firefox aimed at improving audio manipulation through an intuitive toolbar interface. It offers three main features: volume control, balance adjustment, and sound amplification. Users can set volume levels from 0 to 100 and adjust the balance between left and right speakers from -100% to +100%. Additionally, the add-on provides an amplification feature that can boost audio output up to 500%, catering to various listening preferences.

This add-on remembers individual settings for each tab, ensuring that users can customize their audio experience without affecting other tabs. However, it is worth noting that it only works with HTML5 audio and video elements and does not influence media embedded within frames. Overall, Sound Adjustment serves as a practical tool for Firefox users looking to personalize their audio settings efficiently.