An acoustic logging tool including an elongated body, one or more acoustic transmitters,
one or more acoustic receivers, and a broadband acoustic absorption region. A substantial
portion of the broadband acoustic absorption region is between the transmitter
and the receiver. The acoustic energy absorber includes a first absorber for absorbing
a first mode of acoustic energy and a second absorber for absorbing a second mode
of acoustic energy. The acoustic absorption material used to make the acoustic
absorbers has an acoustic impedance between 20% and 120% of the material used to
construct the acoustic logging tool. The acoustic logging tool includes an elongated
hollow tool body, an insert configured to be inserted into the tool body, and a
ring configured to be inserted onto the insert. A first element is supported by
the ring and exposed to a pressure field, and a second element is supported by
the ring and exposed to a pressure field. The first element and the second element
translate pressure from outside the tool body to the ring. The first element is
supported on the opposite side of the ring from the second element, so that pressure
translated to the ring by the first element substantially cancels the pressure
translated to the ring by the second element. The ring substantially acoustically
isolates the first and second element from the tool body and the insert.
