Estimate attenuation of sound pressure level

attenuation estimates atmospheric attenuation and atmospheric absorption.

Usage

attenuation(
  frequency,
  dist0,
  dist,
  temp = 20,
  rh = 60,
  pa = 101325,
  hab.att.coef = 0.02
)

Arguments

frequency

Numeric vector of length 1 with frequency (in Hertz).

dist0

Numeric vector of length 1 with distance (m) for the reference SPL.

dist

Numeric vector of length 1 with distance (m) over which a sound propagates.

temp

Numeric vector of length 1 with frequency (in Celsius). Default is 20.

rh

Numeric vector of length 1 with relative humidity (in percentage). Default is 60.

pa

Numeric vector of length 1 with atmospheric (barometric) pressure in Pa (standard: 101325, default). Used for atmospheric attenuation.

hab.att.coef

Attenuation coefficient of the habitat (in dB/kHz/m).

Value

Returns the geometric, atmospheric and habitat attenuation (in dB) as well as the combined attenuation.

Details

Calculate the geometric, atmospheric and habitat attenuation and the overall expected attenuation (the sum of the other three) based on temperature, relative humidity, atmospheric pressure and sound frequency. Attenuation values are given in dB. The function is modified from http://www.sengpielaudio.com

References

Araya-Salas M., E. Grabarczyk, M. Quiroz-Oliva, A. Garcia-Rodriguez, A. Rico-Guevara. (2023), baRulho: an R package to quantify degradation in animal acoustic signals .bioRxiv 2023.11.22.568305.

See also

Other miscellaneous: add_noise(), noise_profile()

Author

Marcelo Araya-Salas (marcelo.araya@ucr.ac.cr)

Examples

{
  # measure attenuation
  attenuation(frequency = 2000, dist = 50, dist0 = 1)
}
#>   frequency dist geometric.attenuation atmopheric.attenuation
#> 1      2000   50               33.9794              0.4547757
#>   habitat.attenuation combined.attenuation
#> 1                1.96             36.39418