"Ears" is an external signal input module with a contact microphone, which was collaborated by module maker Music Thing centering around DIY kit and Mutable Instruments. It is based on the Music Thing Mikrophonie module.
* This product is a finished product manufactured by the manufacturer and comes with a one-year manufacturer's warranty as usual.
Ears amplifies the vibration generated by hitting or scratching the contact microphone in the lower half of the plate and feeding back the sound from the speaker, and can be pulled up to a modular level and taken out. It is also possible to amplify the sound of an external device patched to the "IN" jack (synth, drum machine, iPhone, etc.). The impedance of the external input is set to high (1 MΩ), so you can connect a guitar to the IN jack.
Since the maximum input gain is 40 dB, line level volume can be boosted with a margin. It is designed to have the lowest noise and distortion possible.
Also, it has an envelope follower output, and the volume change of the input sound can be taken out as an envelope. The attack release of the envelope can be set with a jumper on the back of the board. It also has a gate output (8V), and sensitivity can be set in 3 stages with jumpers on the back of the board.

Jumper settings
From the left, the LEDs indicate clipping, envelope follower voltage level, and gate output.
Mutable Instruments reacts sensitively to triggers
Rings,
ElementsIt is also suitable as a trigger source for physical modeling / resonator modules such as, and will produce different tones depending on how the contact microphone is struck.