The beat frequency heard when two notes are played is 4 Hz. If one of the notes played was 53 Hz, the other note was
A) 57 Hz.
B) 55 Hz.
C) 51 Hz.
D) 49 Hz or 57 Hz.
E) 51 Hz or 55 Hz.

Question

Quizplus · Accepted Answer

The beat frequency is the absolute difference between the frequencies of two notes. Given a beat frequency of 4 Hz and one note at 53 Hz, the other note could be either 4 Hz higher (57 Hz) or 4 Hz lower (49 Hz), hence the correct answer is 49 Hz or 57 Hz.

The Beat Frequency Heard When Two Notes Are Played Is