The dangers facing Chinese white dolphin from marine traffic off south and west Lantau and around Sokos were examined by a WWF-Hong Kong underwater sound study conducted between April and June A total of nine underwater sound recorders collected Chinese white dolphin whistles, dolphin and finless porpoise echolocation clicks and feeding buzzes, as well as vessel noise within the study area. A hydrophone is an underwater microphone connected to a waterproof, rechargeable and portable recorder that can record for two minutes every 10 minutes, for up to 1. The hydrophones we use are specifically designed to cover a wide frequency range — from the very high frequency clicks of finless porpoise to the very low frequency sound of fish chorus and cargo noise. The data is downloaded, followed by recharging the device before it is placed underwater again on the stand, ready for the next recording. Hydrophone data reflect the amount of time cetaceans spend in the area and their behavioral patterns at each deployment location. The acoustic information collected allows us to map potential dolphin foraging and socializing hotspots, as well as significant porpoise foraging habitat see picture on the right. Here are some sample data of the hydrophone taken at night. The spectrogram is a sound frequency profile showing all noise signals recorded. Have a listen.
Instrumentation for Underwater sound and Bioacoustics
The Hydrophone is waterproof up to meters about feet - however the waterproof cable provided is only 33ft and is rugged enough to handle oceanic conditions and water pressures. With this hydrophone, you can record various sounds such as underwater animals and wildlife. The hydrophone can be used in the following environments: Bodies of water lakes, rivers, oceans, etc Underground buried in soil Ice frozen into liquids Swimming pools. This hydrophone can be used in various liquids. Please get approval from Media Loan staff prior to use in potentially hazardous liquids. It was designed with unique large aperture MPC piezo-electric element that responds to sound pressure variations over a wide dynamic range. It is completely encased in a special epoxy casing, which makes it far more rugged than most other under-water microphone designs. This hydrophone is fitted with a standard 3-pin XLR connector.
CRT offers both hydrophones and hydrophone systems. CR2 hydrophones are not individually calibrated, but calibrated frequency response measurements can be performed for an additional fee. The hydrophones are powered by one 9V battery not included or an optional long-life rechargeable, external power supply. Scroll To Top. Hydrophones overview of all models Custom orders gladly accepted such as gain or bandwidth modifications.
Dolphinear hydrophone systems allow us to explore an unseen world - a world where sound rather than light is dominant. So whether you are interested in discovering new worlds, or need a tool to make the present one better and safer, please have a closer look at what we have to offer. Our newest DE series hydrophone comes as a complete kit - hydrophone, cable, headset amplifier, ear- phones, instructions. It's ready to use as soon as you unpack it.