The discomfort you're feeling is completely justified, especially if you work in a shared space where you hear the audio or it breaks your concentration. Long voice messages are annoying for exactly the reason others mentioned: you can't read them at your own pace, they force you to just listen. If a colleague sends you a three-minute voice message knowing you're at work, that's not negligence - that's a lack of consideration.
That said, before you confront her directly, you should figure out if she's even aware she's bothering you. Maybe she thinks it's faster to record than to type, without realizing the impact on whoever receives it. If you feel your relationship allows for it, you could try saying something like "ah, with long voice messages I kind of lose track, I'd prefer written messages when you message me during work" - that way you give your feedback without sounding accusatory.
If it's a recurring thing and talking to her directly isn't possible, the simplest solution is to mute WhatsApp notifications during your peak concentration hours, at least until you get around to reading the message later.