Skip to contents

Convert Phon to Sone

ucnv_phon_to_sone.Rd

Convert loudness level (phon) to loudness (sone) using ISO 532 methods.

Usage

ucnv_phon_to_sone(phon, method = c("zwicker", "moore-glasberg"))

Arguments

phon

Numeric; loudness level in phons. Must be non-negative.

method

Character; conversion method. One of:

  • "zwicker" (default): ISO 532-1 Zwicker method with piecewise formula

  • "moore-glasberg": ISO 532-2 Moore-Glasberg method with lookup table

Value

Numeric vector of loudness values in sones

Details

The Zwicker method (ISO 532-1) uses:

  • For phon < 40: sone = (phon / 40)^(1/0.35)

  • For phon >= 40: sone = 2^((phon - 40) / 10)

The Moore-Glasberg method (ISO 532-2) uses a lookup table with 23 reference points and log-linear interpolation.

By definition, 1 sone = 40 phons (a 1 kHz tone at 40 dB SPL).

Vectorization

This function is fully vectorized and can process vectors of phon values efficiently.

See also

ucnv_sone_to_phon(), ucnv_db_and_hz_to_phon(), ucnv_phon_and_hz_to_db()

Examples

# Reference value
ucnv_phon_to_sone(40)  # Returns 1.0 (by definition)
#> [1] 1

# Doubling property: +10 phon ~= 2x loudness
ucnv_phon_to_sone(50)  # Returns ~2.0
#> [1] 2
ucnv_phon_to_sone(60)  # Returns ~4.0
#> [1] 4

# Low levels (below 40 phon)
ucnv_phon_to_sone(20)  # Returns ~0.15
#> [1] 0.1380112

# Vectorized
ucnv_phon_to_sone(c(20, 40, 60, 80))
#> [1]  0.1380112  1.0000000  4.0000000 16.0000000

# Moore-Glasberg method
ucnv_phon_to_sone(40, method = "moore-glasberg")
#> [1] 1