SonoAlti 2V
Instructions for replacing sounds
Sound files (choose one)
Loud Sounds With Distortion (recommended): SonoAlti_2V_Sounds.zip
Quieter Sounds With No Distortion (recommended for earbuds or earphones): SonoAlti_2V_Sounds.zip

Firmware tools & latest update
Flash Revealer: SonoAlti_2V_Flash_Revealer.zip
Firmware Version 1.7: SonoAlti_2V_Firmware_1_7.zip

Flash Eraser (optional to use, reformats entire flash chip): Flash_Eraser_SAMD51.zip