Sound pressure level spectra measured from different distances for the three sonar units. Daniel DengZ. L. SouthallBrandon J. CarlsonThomas XuJinshan J. MartinezJayson A. WeilandMark M. IngrahamJohn 2014 <p><b>A</b>. Kongsberg; <b>B</b>. BioSonics; <b>C</b>. Imagenex.</p>