Biologist Roger Payne is best known for his discovery that whales sing songs. In 1970, he released an LP called “Songs of the Humpback Whale.” It played a key role in igniting the modern environmental movement, and helped bring whales back from the brink of extinction.

Through his organization Wild Sanctuary, Bernie Krause has travelled the globe to hear and record the sounds of diverse natural habitats. 

Some years ago a young woman emailed us for some information about our Dolphinear hydrophones. She said they had been recommended by biologist Roger Payne during a course she had taken. He wrote the foreword to the Bernie Krause book “Wild Soundscapes: Discovering the Voice of the Natural World” where an entre chapter is devoted to equipment.

When it came to hydrophones he wrote: “Hydrophones are designed to record underwater, in saltwater marine environments or lakes and pond (figure 12) ‘Hydrophone by Dolphinear’ (which pictured our DolphinEar PRO model).

“Fully functional models can be had inexpensively. More expensive models can cost upward of several thousand dollars but are neither practical nor particularly useful unless one is doing serious research that requires careful calibration.

Referring to the DolphinEar model in the photo: “Because of their excellent low- frequency response, we have been able to record elephant and hippo infrasound in air; very few reasonably priced microphones are able to capture this range of sound. We have buried hydrophones under the sand to record the singing of the dunes. We have also recorded the signatures of earthworms crawling through the soil with these instruments.”

link: Wild Soundscapes: Discovering the Voice of the Natural World   

The sound of an ant nest in winter: “Then after relocating to the Northumberland Wildlife Trust Reserve, a mixed coniferous and deciduous woodland in the valley of Holystone Burn, in bright sunshine, now calm, colder, but superbly clear conditions.

“We located a hairy wood ant nest after some alarm that our initial nest sites had been destroyed by forestry logging operations, and we carefully inserted 2 DolphinEar PRO hydrophones into the nest, approximately 20 cm into the main body of the nest on the south-facing side.

“The nest was completely covered in snow and apparently inactive. We returned 15 minutes later to allow settlement and expecting more activity as the sun shone directly onto the nest. Listening revealed surprising levels of activity, despite the cold, but there were no visible signs of the occupants of the nest!” -Chris Watson and Jana Winderen

“As a composer and instrumentalist, I have always leaned toward colour and texture over traditional composition methods. In my role as a researcher at Wintec, I have been fortunate enough to indulge this desire to record and manipulate sound sourced from unfamiliar environments.

“By utilising hydrophones, I am able to make subaquatic and subterranean recordings with huge amounts of detail. The recording below is from a live performance utilising the same 5 minute underwater recording from Merri Creek in Melbourne, Australia.

The source sound is processed using Native Instruments Guitar Rig software and Curtis by The Strange Agency.

“The hydrophones I use are DolphinEar PRO. My recordings are captured on a Zoom H2. This recording captures one of twelve, twenty minute improvised performances created as part of the 14th Liquid Architecture sound art festival in Melbourne, Australia. The performances consisted of 4 x 5 minute manipulations of the same subaquatic recording from Merri creek.

“The performances were presented in the RMIT reverberation chamber. 150 tonnes of concrete structure isolated from any solid structures. 115 cubic metres of reflection and diffusion. The recording was taken directly from the mixing console and then an impulse response from the chamber was used to recreate the sonic behaviour of the space.”
-Kent MacPherson – Sound Art and Research

“The Bubbling Beach  17 August, 2011

“Here’s a novelty…

“I was recording this morning at Hauxley, Northumberland (warm and sunny, nice whimbrel, knot and roseate terns – shame about the F-15s) when I noticed that the beach around me was making a significant contribution to the soundscape.

“At first I thought that the bubbling noise was coming from lugworm burrows, but then I realised that I’d never heard lugworm burrows make a noise, and that the sound was coming from just a small area of beach.

“Closer inspection revealed that the sand had covered a mass of fermenting kelp, that was producing a constant stream of foul-smelling gas bubbles through the sand.

“So I dug a hole for my DolphinEar PRO hydrophone, and this is the result:

“Fermenting seaweed  Isn’t Nature wonderful!

– “Osprey” blog Glasgow

Further information about methane produced by sea weed here

NOTE: The sound frequency of the pulses is centered around 10-30 Hz so you will need good earphones and good audio equipment to hear it properly.

Dutch artist Roosmarijn Pallandt worked with composer Patrick Farmer of the Sonic Art Research Unit at Oxford Brookes University, UK to produce an audio piece titled Light Sounds Air. The aim: to draw attention to the regenerative nature of life on Earth. The basis of the piece, recorded with a DolphinEar hydrophone, was the frequencies of pulsing tree water transport systems and of photosynthesising aquatic plants (see Photosynthesis in ponds section below).

Presented by Roosmarijn Pallandt at the United Nation’s COP26 Climate Conference in Glasgow, it served as a poignant reminder that there’s still so much we don’t know about life on this planet, yet we treat ourselves as the gods of it. These sounds are of water passing through the roots of a horse chestnut sapling. Remarkable! This sound can be followed up the tree trunk, even as far as the leaves. Many researchers describe this as the ‘living pulse’ of trees.

“We live in an age where, whilst some of our senses are oversaturated, others are deprived. The sounds within my recent work lie beyond the domain of our hearing. They are an invitation to expand our relationship with the sensory elements of the world – noticing our environment as a whole.

“All of the sounds were gathered in UK ponds and forests miles away from the conference centre. It was important to me that the sounds were all recorded in the UK. To get the field recordings, I collaborated with Dolphin Ear Global hydrophones and composer Patrick Farmer.” –Roosmarijn Pallandt

Recording of vent air coming out of a south icelandic fumarole. Lovely, gentle sounds of rising steam contrast the expectation of a volcano. The DolphinEar PRO series hydrophone stood up to the heat very well!

This sound clip is from a single midshipman fish recorded using a DolphinEar DE200 hydrophone in British Columbia, Canada. Midshipman fish depend on acoustic communication to find mates. Males emit loud continuous droaning sounds to advertise their location. This encourages females to lay eggs in the males’ nests. The hum is a low-pitched sound generated by the rapid contraction of the drumming muscles on the male’s swim bladder.

Unlike birds or whales, fish don’t sing with their lungs. Instead, they have evolved quirky ways to use their bodies to make noise, creating thumps, honks, burps, rattles, clicks and more. They use these sounds for a variety of communication purposes such as courting mates, defending territory and social interaction.

This is an area of research where the keen amateur recordist can join in the fun. Use your DolphinEar hydrophone to record fish sounds, noting the type of fish, location and date. Many people tell us it is more satisfying to bag a new sound than to bag a few fish for dinner – and you don’t need a licence to fish for sounds!

One of our customers, Fred C, lives on a houseboat in the fjords of British Columbia, Canada. For many years he has used a DolphinEar Hydrophone to listen to sounds around his floating home. Sea Lions are frequent visitors.

This sound clip was made during the sea lion mating season. Their underwater barks, and grunts can be heard clearly at a distance of over 300 metres using a DolphinEar DE200 hydrophone.

In freshwater ponds, photosynthesis is the primary process by which plants convert sunlight, carbon dioxide (CO2), and water into chemical energy (sugars) and release oxygen (O2). This is crucial for the entire pond ecosystem, forming the base of the food web and maintaining oxygen levels for fish and other aquatic life. Bubbles of oxygen form on the leaves of underwater plants. When they are released a ‘ping’ sound occurs. That is what you are hearing in this recording made by a DolphinEar DE200 hydrophone that was placed in as small freshwater forest pond in the UK. Photosynthesis starts in the morning as the sun lights the pond and turn off when night arrives.

Jay Bowerman with a 20 year old DolphinEar

Oregon Spotted Frog

While traditionally used for marine biology, researchers employ DolphinEar hydrophones to detect and record frog species that call underwater.

Enhanced Detection: Hydrophones are significantly more effective than standard microphones or human observers for monitoring underwater-calling frogs. Studies show they can be 30 times more likely to detect these submerged calls.

Extended Range: These devices can detect underwater frog calls from as far as 65 meters away, especially in deeper water (over 50 cm) with fewer obstructions like logs.

Species Identification: They are essential for expanding the known list of underwater-vocalizing frog species, as many calls are impossible to hear from the surface.

Technical Suitability
The DolphinEar PRO is favored for field study due to its specific design features:

Omnidirectional Sensing: Captures sound from all directions, which is ideal for locating frogs in murky wetland environments.

Wide Frequency Range: Covers 1 Hz to 24,000 Hz, capturing the full spectrum of frog vocalizations.

Rugged Design: Built to withstand harsh field conditions, including burial in earth or sand (acting as a geophone) or direct immersion in hazardous wetland areas.

Ease of Use: It connects directly to standard recording equipment via XLR without requiring phantom power, reducing the risk of equipment failure in wet environments.

Low res images of sonograms made using Spectrogram software which is included with every DolphinEar Hydrophone.