Hi,

I'm struggling to get the right values for medium.alpha_coeff and medium.alpha_power. I'm working from the "Attenuation of sound in air" table from

http://www.kayelaby.npl.co.uk/general_physics/2_4/2_4_1.html.

From their data I got an approximate fitting formula of y=5.3273*x^1.4484 (for 50% humidity) where y is the attenuation coefficient in [dB/km] and x is the frequency in [kHz].

I assume since medium.alpha_coeff is measured in [dB/(MHz^y cm]) I cant use 5.3273 as is. Would 0.053273 be the correct value for medium.alpha_coeff in [dB/(MHz^y cm)]?

Kind regards,

PiesangBrood2000