What term is used by audio engineers to describe frequency or pitch adjustments for playback equipment?

The term used by audio engineers to describe frequency or pitch adjustments for playback equipment is "tones." This term refers to the adjustments made to the various frequency ranges within a sound signal to enhance or modify the sound quality. Tones can affect aspects such as bass, midrange, and treble, allowing audio engineers to tailor audio playback to achieve a desired sound profile. This can involve boosting or cutting certain frequencies to improve clarity or to match the acoustics of a particular space or the quality of the playback equipment.

In contrast, the other options refer to different aspects of sound and audio management. Volume control pertains specifically to the overall loudness of the sound, rather than its tonal characteristics. Frequencies represent the specific sound waves but do not denote the act of adjusting them for playback. Sound levels indicate the intensity of sound being output but do not directly relate to the adjustments made on frequency or pitch.