# f2st: Convert between frequency in Hz and in semitones In hqmisc: Miscellaneous Convenience Functions and Dataset

 f2st R Documentation

## Convert between frequency in Hz and in semitones

### Description

Convert between frequency in Hz and in semitones, relative to baseline frequency in Hz.

### Usage

```f2st( hz, base=50 )
st2f( st, base=50 )
```

### Arguments

 `hz` a frequency in Hertz (cycles per second). `st` a frequency in semitones relative to the base frequency. `base` the baseline frequency (in Hertz units) relative to which semitones are expressed.

### Details

These functions convert between the linear Hertz and logarithmic semitone scales. A doubling of the frequency in Hz equals 12 semitones or 1 octave.

Function `f2st` was based on function `h2st` by Mark Liberman
(last seen at http://ldc.upenn.edu/myl/llog/semitones.R but no longer available online).
Function `st2f` was based on a conversion script by Jan Roelof de Pijper
(last seen at http://users.abo.fi/jtuomain/speech/semitone.html but no longer available online).

For frequencies in Hz of musical notes, see e.g. http://www.phy.mtu.edu/~suits/notefreqs.html.

### Value

Transformed value(s) in semitones or in Hertz (cycles per second).

`f2bark, bark2f, f2mel, mel2f.`

### Examples

```# distance in semitones between target and baseline frequencies in Hz.
f2st( 440, base=110 )

# frequency in Hz of a tone that is +24 semitones distant
# from the baseline, i.e. a distance of +two octaves.
st2f( 24 )
```

hqmisc documentation built on May 9, 2022, 5:08 p.m.