Beat frequency: the number of beats per second, equal to the difference in the frequencies of two interacting tones or oscillations.
#underline(bb("Case" color(white)(.....................) "Beat Frequency"))#
#color(white)(..)"A" color(white)(.....................) "149 Hz - 145 Hz = 4 Hz"#
#color(white)(..)"B" color(white)(......................) "22 Hz - 12 Hz = 10 Hz"#
#color(white)(..)"C" color(white)(.....................) "900 Hz - 901 Hz = 1 Hz"#
#color(white)(..)"D" color(white)(.....................) "338 Hz - 332 Hz = 6 Hz"#
Order of beat frequency: #"B > D > A > C"#