If you wish to get a gaggle of music aficionados all stirred up, carry up autotune. This audio processing system measures a singer’s vocal pitch and makes use of processing software program to appropriate it in order that they will by no means go off-key. Some folks love the impact, whereas others imagine it utterly ruins a musician’s pure singing voice, or is little greater than a crutch to assist poor singers sound higher.
Engineer and {hardware} hacker Man Dupont is a fan of autotune and thinks that the impact ought to be used nicely past simply vocal correction. So Dupont determined to construct an unlikely instrument — a kazoo with a built-in autotune-like system.
Eradicating the {hardware} elements (📷: Man Dupont)
For these unfamiliar with how a kazoo works, the musician vocalizes into one finish of the instrument. This causes a membrane on the prime to vibrate, which in flip creates a kind of buzzing sound. The pitch it produces is managed by the musician’s pitch, so going off-key is not going to produce a really pleasing consequence. At the very least not with out Dupont’s autotune.
The fundamental plan concerned utilizing a microphone contained in the kazoo to seize the musician’s buzzing, a microcontroller to appropriate it, and a speaker to vibrate the kazoo’s membrane with the corrected notice. Because it turned out, this didn’t work very nicely in any respect. The microphone and speaker had been too shut collectively, leading to suggestions. Moreover, placing a microphone in a plastic tube isn’t any strategy to get a very good audio pattern — it may solely decide up poor high quality, ringing sounds.
After a little bit of considering and trial and error, Dupont determined to maneuver the microphone immediately in-mouth to keep away from these issues. Additionally, the kazoo’s membrane was eliminated such that sound may come immediately from the speaker itself. With these alterations the kazoo was probably not a kazoo anymore, however the sound was a lot better.
The kazoo can management absolutely anything by way of MIDI (📷: Man Dupont)
It was nonetheless not fairly kazoo-like sufficient, nevertheless. So Dupont added buzzy harmonics within the processing algorithm, and in addition cheated by all the time producing a sawtooth wave that merely matched the frequency pitch detected by a YIN basic frequency estimation algorithm.
The {hardware} consists of an I2S MEMS microphone that was encased in foam and a 3D-printed case earlier than getting a layer of scorching glue to seal it for in-mouth use. This was wired to a Seeed Studio XIAO growth board with an ESP32-S3 microcontroller that was hidden contained in the kazoo. Additionally included was an amplifier, speaker, and rechargeable lithium-ion battery.
Do you have to tire of the kazoo sound, the instrument will also be used as a wi-fi MIDI controller for nearly any synthesizer. It could be a little bit of an oddball machine, but it surely does appear like it could be enjoyable to mess around with. Remember to try the video for some demonstrations of the kazoo.