HzToOther: Convert between Hz and other frequency scales

In soundgen: Sound Synthesis and Acoustic Analysis

Convert between Hz and other frequency scales

Description

Converts between Hz and ERB, bark, mel, log, semitones relative to a reference frequency, or musical notes. Accepts vectors and missing values.

Usage

HzToOther(
  x,
  scale = c("ERB", "bark", "mel", "log", "semitones", "notes", "linear", "orig"),
  ...
)

otherToHz(
  x,
  scale = c("ERB", "bark", "mel", "log", "semitones", "notes", "linear", "orig"),
  ...
)

Arguments

x	vector or matrix of frequencies
scale	target scale: "bark" = Zwicker's critical bandwidth scale calculated as in Wang et al. 1992 (see https://en.wikipedia.org/wiki/Bark_scale), "mel" = O'Shaughnessy's original formula (https://en.wikipedia.org/wiki/Mel_scale), "ERB" = Equivalent Rectangular Bandwidth rate (see Moore & Glasberg 1983, 1990), "log" = log2, "semitones" = semitones relative to a reference value, "notes" = musical notation, "linear" or "orig" = no change
...	other arguments passed on to the scale-specific function

Value

Numeric vector of converted frequencies.

Scale‑specific arguments

The following arguments can be passed via ... . They are only used when the corresponding scale is selected; otherwise, they are silently ignored.

method

Character, used when scale = "ERB". Choose between "linear" (Glasberg & Moore, 1990) and "quadratic" (Moore & Glasberg, 1983). Default is "linear".

ref

Numeric, used when scale = "semitones". Reference frequency (Hz) for the semitone scale. Default is C-5 (0.5109875 Hz).

A4

Numeric, used when scale = "notes". Frequency of the note A4. Default is 440 Hz (modern standard ISO 16, concert pitch).

showCents

Logical, used only with HzToOther() when scale = "notes". If TRUE, appends the cent deviation (rounded to the nearest integer) to the note name. Default is FALSE. Not applicable to otherToHz().

No additional arguments are required or usedor scale = "bark", "mel", "log", or "linear".

References

• Moore, B. C., & Glasberg, B. R. (1983). Suggested formulae for calculating auditory-filter bandwidths and excitation patterns. The journal of the acoustical society of America, 74(3), 750-753.

• Glasberg, B. R., & Moore, B. C. (1990). Derivation of auditory filter shapes from notched-noise data. Hearing research, 47(1-2), 103-138.

Examples

x = c(-20, 20, 100, 440, 1000, NA)
HzToOther(x, 'ERB')
HzToOther(x, 'ERB', 'quadratic')
HzToOther(x, 'bark')
HzToOther(x, 'mel')
HzToOther(x, 'log')
HzToOther(x, 'semitones', ref = 16)
HzToOther(x, 'notes', showCents = TRUE)

# ...and back to Hz
x = c(0:10, NA)

otherToHz(x, 'ERB')
otherToHz(x, 'ERB', method = 'quadratic')
otherToHz(HzToOther(c(100, 440, 2000), 'ERB'), 'ERB')

otherToHz(x, 'bark')
otherToHz(HzToOther(c(100, 440, 2000), 'bark'), 'bark')

otherToHz(x, 'mel')
otherToHz(HzToOther(c(100, 440, 2000), 'mel'), 'mel')

otherToHz(x, 'log')

otherToHz(x, 'semitones')
HzToOther(c(440, 210, 880), 'semitones', ref = 440)
otherToHz(HzToOther(c(440, 210, 880), 'semitones'), 'semitones')

otherToHz(c('A4', 'C#6', 'blabla', 'C0', 'C-2', NA), 'notes')
HzToOther(c(440, 293, 115, 16.35, 4), 'notes')

HzToOther(c(440, 415, 80, 81), 'notes', showCents = TRUE)
# 80 Hz is almost exactly midway (+49 cents) between D#2 and E2

# Baroque tuning A415, half a semitone flat relative to concert pitch A440
HzToOther(c(440, 415, 16.35), 'notes', A4 = 415)
otherToHz(c("A4", "D4", "A#2", "C0", "C-2"), 'notes', A4 = 415)

soundgen documentation built on Sept. 20, 2026, 5:07 p.m.