An apparatus for acoustic monitoring, the apparatus comprising: an ablation catheter, comprising: an elongated catheter body extending longitudinally between a proximal end and a distal end along a longitudinal axis; a distal member disposed adjacent the distal end, the distal member including an ablation element to ablate a biological member at a target region outside the catheter body; one or more acoustic transducers disposed in the distal member and each configured to direct an acoustic signal toward a respective target ablation region and receive reflection echoes therefrom; and an acoustic redirection member disposed in the distal member to at least partially redirect the acoustic signal from at least one of the acoustic transducers toward a tissue target; wherein the distal member includes a most-distal portion, a proximal portion, and a deflectable portion between the most-distal portion and the proximal portion to permit deflection between the most-distal portion and the proximal portion of the distal member, the deflectable portion being more deflectable than at least one of the most-distal portion or the proximal portion; and wherein (i) the one or more acoustic transducers are mounted to the most-distal portion and the acoustic redirection member is mounted to the proximal portion, or (ii) the one or more acoustic transducers are mounted to the proximal portion and the acoustic redirection member is mounted to the most-distal portion of the distal member. an ablation catheter, comprising: an elongated catheter body extending longitudinally between a proximal end and a distal end along a longitudinal axis; a distal member disposed adjacent the distal end, the distal member including an ablation element to ablate a biological member at a target region outside the catheter body; one or more acoustic transducers disposed in the distal member and each configured to direct an acoustic signal toward a respective target ablation region and receive reflection echoes therefrom; and an acoustic redirection member disposed in the distal member to at least partially redirect the acoustic signal from at least one of the acoustic transducers toward a tissue target; wherein the distal member includes a most-distal portion, a proximal portion, and a deflectable portion between the most-distal portion and the proximal portion to permit deflection between the most-distal portion and the proximal portion of the distal member, the deflectable portion being more deflectable than at least one of the most-distal portion or the proximal portion; and wherein (i) the one or more acoustic transducers are mounted to the most-distal portion and the acoustic redirection member is mounted to the proximal portion, or (ii) the one or more acoustic transducers are mounted to the proximal portion and the acoustic redirection member is mounted to the most-distal portion of the distal member. an elongated catheter body extending longitudinally between a proximal end and a distal end along a longitudinal axis; a distal member disposed adjacent the distal end, the distal member including an ablation element to ablate a biological member at a target region outside the catheter body; one or more acoustic transducers disposed in the distal member and each configured to direct an acoustic signal toward a respective target ablation region and receive reflection echoes therefrom; and an acoustic redirection member disposed in the distal member to at least partially redirect the acoustic signal from at least one of the acoustic transducers toward a tissue target; wherein the distal member includes a most-distal portion, a proximal portion, and a deflectable portion between the most-distal portion and the proximal portion to permit deflection between the most-distal portion and the proximal portion of the distal member, the deflectable portion being more deflectable than at least one of the most-distal portion or the proximal portion; and wherein (i) the one or more acoustic transducers are mounted to the most-distal portion and the acoustic redirection member is mounted to the proximal portion, or (ii) the one or more acoustic transducers are mounted to the proximal portion and the acoustic redirection member is mounted to the most-distal portion of the distal member.