How to Make a Hydrophone for Exciting Underwater Sounds #CitizenScience #Arduino @seaperch

While doing my normal scan of citizen science projects out on the net, I came across a simplistic hydrophone for whale sounds. While I know there are professional mic systems for this type of work, I had no idea the DIY community had been working on solutions as well. Needless to say, I ventured down the rabbit hole of all things dealing with underwater microphones. Projects ranged from a solder-less variety for educational purposes to an inexpensive recording style device. However, the one that won my heart was designed by Philip Cox for the Seaperch platform. Philip is part of the Utah Underwater Robotics (UUR) program, matching college students and volunteer teachers with middle school students for STEM learning.

This hydrophone uses an Arduino and Processing for a visual display, which is what makes this device so fun. A simple electret microphone is placed in a recycled film canister filled with mineral oil. That sounds crazy if you don’t know science, but Phil explains it all in his report.

First, it allows the waves to propagate more continuously through liquids, rather than traveling through air. Second it helps prevent leakage of water into the cavity, causing damage to the microphone. Finally, it also helps with lowering the buoyancy of the microphone while under water.

With a bit of sealant and electrical tape, it’s ready to go. One of the nice touches here is the connectors that Phil adds, making things more modular. The film canister is also a cool find, although they will get harder to locate as everything has gone digital; perhaps a small Tupperware is next.  As with any project there are other things that can be explored. The tutorial does not mention whether the Processing or Arduino code addresses the scale of the sound. For instance, an LED could change different colors based on whether a sound is from a whale vs. a dolphin. In fact, the audio could be used to generate some interesting artwork using the Processing. There are so many fun possibilities for this little gadget and I’m glad to have made the discovery. If you want to give this project a go, we have an Electret Microphone Amplifier for you. You can also check out a project that uses this mic—the Adafruit Microphone Amplifier Breakout. See how the mic is used here with a bi-color LED matrix to visualize the sounds. Who knew mics could be so much fun?

Adafruit Microphone Breakout Project

As 2022 starts, let’s take some time to share our goals for CircuitPython in 2022. Just like past years (full summary 2019, 2020, and 2021), we’d like everyone in the CircuitPython community to contribute by posting their thoughts to some public place on the Internet. Here are a few ways to post: a video on YouTub, a post on the CircuitPython forum, a blog post on your site, a series of Tweets, a Gist on GitHub. We want to hear from you. When you post, please add #CircuitPython2022 and email to let us know about your post so we can blog it up here.

Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.

Join 32,000+ makers on Adafruit’s Discord channels and be part of the community!

Have an amazing project to share? The Electronics Show and Tell is every Wednesday at 7pm ET! To join, head over to YouTube and check out the show’s live chat – we’ll post the link there.

Join us every Wednesday night at 8pm ET for Ask an Engineer!

Follow Adafruit on Instagram for top secret new products, behinds the scenes and more

CircuitPython – The easiest way to program microcontrollers –

Maker Business — Pololu’s account of the chip shortage

Wearables — Monster-inspired costuming!

Electronics — How to make your own magnetic field probe!

Python for Microcontrollers — Python on Microcontrollers Newsletter: New Releases of MicroPython and CircuitPython and more! #Python #CircuitPython @micropython @ThePSF

Adafruit IoT Monthly — 2021 in Recap!

Microsoft MakeCode — MakeCode Thank You!

EYE on NPI — Maxim’s Himalaya uSLIC Step-Down Power Module #EyeOnNPI @maximintegrated @digikey

New Products – Adafruit Industries – Makers, hackers, artists, designers and engineers! — New Products 1/19/22 Feat. Adafruit 7-Segment LED Matrix Backpack – STEMMA QT / qwiic!

Get the only spam-free daily newsletter about wearables, running a "maker business", electronic tips and more! Subscribe at !

No Comments

No comments yet.

Sorry, the comment form is closed at this time.