What is it?

Welcome to fascinating world of bats! This Bat Listener kit can hear the ultrasonic sounds created by bats and convert them to a lower frequency so that you can hear them communicate, navigate and seek them!

Bats use ultra-sonic pulses to navigate and to detect prey. These pulses are very high pitch, in the region of 40-120kHz, around 5 times the maximum frequency humans can hear. The Bat Listener is an electronic circuit that converts the high pitched sounds produced by bats to a human-audible level. For extra fun use the Bat Listener to investigate other gadgets which make a high frequency noise .

You can hear compact fluorescent lights screaming away, the squeaks from sticky tape as it is unwrapped and the high frequency power supplies which power the back-lights in phones and laptops.

This kit has also been used to check if ultrasonic pet scarers are still working, check for gasses leaking from pipes and listen to the noises made by rats!

Why did you make it?

This kit was originally designed as a Xmas present for my Dad, who had seen bats in the garden. I then ran this as a workshop at Nottingham Hackspace (nottinghack.org.uk) and from there I decided to turn it into a kit to sell. I have recently updated this kit based upon feedback, and its now quicker to build, needs less fiddly wires and the end unit is much nicer to use. I've also added a visual indication of the output and, for more advanced users, an output for monitoring by an arduino or other microcontroller.

Included in the kit

• Bat Listener Printed Circuit Board
• 16x Capacitors
• 13x Resistors
• 3x Integrated Circuits (ICs)
• 3x IC Socket Connectors
• 4x Diodes
• Transistor
• Ultrasonic Receiver
• Speaker
• Switch
• Potentiometer
• Instruction Booklet
• Acrylic Enclosure and all fixings.

Please note: While not difficult to make, this kit does require quite a lot of soldering. It is recommended for people who have already done a bit of soldering and will take in the region of 1-3 hours to solder.

PCB files and DXF enclosure files are all here: https://github.com/curiouselectric/batlistener

I send items from the UK. Typically using Royal Mail 'Tracked 48' service in the UK. Orders for overseas (both EU and worldwide) will be sent with the most appropriate mail service, but usually Royal Mail international tracked.

I aim to send items within 3-5 working days (typically 1-2 days).

For international customers outside the UK: Import duties, taxes and all other fees are the recipient's responsibility.