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Underwater sound recorder

sound recorders
Two Underwater Sound Recorders ready for deployment

The CMST Underwater Sound Recorder (USR) is an innovative device capable of autonomously collecting large amounts of acoustic data under a range of sampling schemes. The USR can be deployed for up to two years and is particularly suited to long term monitoring of man-made and natural underwater sound. It has been successfully used for studies of biological sea noise (fish, whales, etc.), physical sea noise (breaking waves), and a variety of man-made underwater sounds.

sound recorder
Underwater Sound Recorder Internals


  • Integral Pre-Amplifier (20dB gain, user selectable lower frequency cutoff filter – 8Hz or 160Hz).
  • Integral Anti-Aliasing Filter (0-20db pre filter gain, 6th order Butterworth filter, high frequency cut off from 1kHz to 15kHz, additionally 0-20dB of post filter gain is available on a secondary output).
  • 16 bit Analog to Digital Conversion (RMS noise of A/D – 3 quantisation levels) (Note: total recorded noise level depends on hydrophone capacitance, pre-amplifier used, amplifier gain, cut-off frequency, etc).
  • Power Supply, GPS and Terminal Interface Card.
  • IDE Hard disk drive interface card.
  • Processor card with onboard sea noise recorder firmware and Compact Flash interface; User configurable via RS232 interface (sampling rate (up to 26k samples/sec), bandwidth, gain, sampling durations, record intervals) (support for two user configured sampling schedules).
blue whale call
Blue whale calls off Rottnest – January 2002
  • Data Storage – one 2.5″ hard disk drives (size determined by availability, generally in the region of 60GB to 160GB) and Type 1 Compact Flash Card (256MB) (The hard drives use FAT32 file structure and can be read with a standard Windows PC – individual files for each recording event).

All electronics fixed to a mounting plate and are designed to suit a 100mm ID housing.

A range of analytical software is also available on negotiation. Specifications are subject to change and continuous improvement.