Study of acoustic transmission loss in sediments at low frequencies using parametric acoustic arrays

Abstract

Investigations have been carried out on the acoustic transmission loss in clay, sand, and gravel in the frequency range 6–10 kHz. Parametric acoustic arrays have been used for this study and have been generated using amplitude modulation of a primary transducer of frequency about 300 kHz in which the carrier was suppressed. Source level and beam width of the parametric signal have been ∼ 155 dB re: |μPa/m2 and 3.6°, respectively. Experiments have been conducted in the laboratory taking the sediment in a rectangular container of dimensions 0.7×0.49×0.6 m3. The acoustic transmission loss using parametric arrays has been compared with the measured loss with a nonparametric source. The results show a dependence of transmission loss on the particle size and are discussed in the light of previous studies.