Convert Frequency to ERB-rate Scale — ucnv_hz_to

Converts frequency values from Hz to the ERB-rate scale (also called ERBS or Cams). The ERB-rate scale is based on the Equivalent Rectangular Bandwidth of auditory filters and provides a perceptually uniform frequency scale.

Usage

ucnv_hz_to_erb(freq, method = c("glasberg1990", "moore1983"), as_units = NULL)

Arguments

freq

Numeric vector or units object with frequency values in Hz. If a units object is provided, it will be converted to Hz.

method

Character string specifying the conversion formula to use. Options are:

"glasberg1990" (default): Glasberg & Moore (1990) linear approximation
"moore1983": Moore & Glasberg (1983) polynomial approximation

as_units

Logical. If TRUE, returns a units object with "ERB" units. If FALSE, returns a plain numeric vector. Default is TRUE if the units package is available and input has units.

Value

If as_units = TRUE and the units package is available: a units object with "ERB" units. Otherwise, a numeric vector of ERB-rate values.

Details

Two different approximation formulas are available:

Glasberg & Moore (1990) (default): $$ERBS(f) = 21.4 \cdot \log_{10}(1 + 0.00437 \cdot f)$$

Valid range: 100-10,000 Hz. This is the most commonly used formula.

Moore & Glasberg (1983): $$ERBS(f) = 11.17 \cdot \ln\left(\frac{f + 312}{f + 14675}\right) + 43.0$$

where f is in Hz. Valid range: 100-6500 Hz.

References

(Glasberg and Moore 1990)

(Moore and Glasberg 1983)

Examples

if (FALSE) { # \dontrun{
# Basic usage
ucnv_hz_to_erb(1000)
ucnv_hz_to_erb(c(100, 500, 1000, 2000, 4000))

# With units package
library(units)
freq <- set_units(1000, Hz)
ucnv_hz_to_erb(freq)

# Different methods
ucnv_hz_to_erb(1000, method = "moore1983")
} # }