554Hz
554 Hz is a frequency that commonly corresponds to the musical note C♯5 (or equivalently D♭5) in the equal‑temperament tuning system. In this system a pitch’s frequency is determined by the formula 440 × 2^(n/12), where n is the number of semitone steps from the reference pitch A4 (440 Hz). For C♯5, which is seven semitones above A4, the calculation yields 440 × 2^(7/12) ≈ 554.37 Hz. The slight deviation between the theoretical 554.37 Hz and the rounded 554 Hz is a result of rounding for practical reference.
In music orchestration and electronic synthesis, 554 Hz is used as a standard pitch for performers and instruments
Beyond music, frequencies around 554 Hz are of interest in acoustics research and psychoacoustics. Studies of timbre
Because of its prominent placement in the harmonic series and its accessibility to a wide range of