I've added voice notes to a Google Slide with mote - can students hear it on an iPad or iPhone?

Students - or anyone else with access to your Slides presentation - can access your mote voice notes using Slides for iPad for iPhone, provided they are viewing the presentation in 'Play' mode

In edit mode (the default view when you open Slides), the audio will not be playable. This is a Google product feature - please raise a request with Google if you'd like your students / recipients to be able to hear your voice notes in edit mode!