Make: Volume 77

Usable human vocal frequencies generally

lie between 300 and 3,000Hz, and a digital

microphone needs to sample more than twice

that rate to create an accurate waveform of the

sound. As a result, processors need to be capable

of sampling at a 6kHz minimum, which helps

explain why 8kHz is a standard audio sampling

rate. While an ARM Cortex-M0+ might work

for analyzing audio, I usually reach for an ARM

Cortex-M4 instead, such as the one found in the

Arduino Nano 33 BLE Sense, to perform inference

with vocal and non-vocal sounds.

Vision: Previously, using machine learning to

analyze and classify images and videos required

powerful desktop computer ...