Corrigendum to “Approximation formulae for the acoustic radiation impedance of a cylindrical pipe” [J. Sound Vib. 322 (2009) 255–263]

The authors regret that the above-mentioned paper contains the erroneous Eq. (20) Z r (ω) = (d 1 − n 1)jka − d 2 (jka) 2 2 − (d 1 + n 1)jka + d 2 (jka) 2 (20) which should have been written as Z r (ω) = (n 1 − d 1)jka + d 2 (jka) 2 2 − (d 1 + n 1)jka + d 2 (jka) 2 (20 ′) i.e. the negative of the published expression, thus leading to the correct unit behaviour for high frequencies. This modification does not affect any other part of the paper and the results in Table (1) are still valid. To the best of our knowledge, we have not found any misuse of this formula in any citing article. The authors would like to apologize for any inconvenience caused and are grateful to Prof. James Beauchamp for drawing the attention to the above-mentioned error.