Regarding the sound absorption coefficients.

[tbelesis]

Greetings! I am trying to simulate an underwater environment with pyroomacoustics. The sound absorption coefficients of media are usually given in either dB/km or dB/100m. What are the units of the air absorption coefficients that exist on the table in the pyroomacoustics documentation? What would be the way to convert coefficients given in dB/km so that they will be suitable for use with pyroomacoustics? Thanks in advance!

[fakufaku]

The same question was asked on the discord, so may it is not necessary to reply here anymore, but out of completeness, I worked out the following.

The impulse response with the absorption applied, h(t) should be given, I think, by

h(t) = h_0(t) 10^(a / 20 (c t) / 1000)

where h_0(t) is the impulse response before applying absorption, a is the absorption coefficient in decibels per kilometer, c the speed of sound in meters per second, and t the time in seconds.
The division by 20 is due to the 10 factor in decibles, and a factor 1/2 due to applying the decay in magnitude rather than energy.
The division by a 1000 converts meters travelled to kilometers.

Now, please check this with some reference material like a text book, because this is not based on a deep knowledge of the domain.