Mailspring/app/internal_packages/custom-sounds/lib/main.es6

import { SoundRegistry } from 'nylas-exports';

export function activate() {
  // FIXME: Use the mailspring:// protocol handlers once we upgrade Electron past
  // v30.0
  // See: https://github.com/atom/electron/issues/1123
  SoundRegistry.register({
    send: ['internal_packages', 'custom-sounds', 'CUSTOM_UI_Send_v1.ogg'],
    confirm: ['internal_packages', 'custom-sounds', 'CUSTOM_UI_Confirm_v1.ogg'],
    'hit-send': ['internal_packages', 'custom-sounds', 'CUSTOM_UI_HitSend_v1.ogg'],
    'new-mail': ['internal_packages', 'custom-sounds', 'CUSTOM_UI_NewMail_v1.ogg'],
  });
}

export function deactivate() {
  SoundRegistry.unregister(['send', 'confirm', 'hit-send', 'new-mail']);
}