This spell is so underwhelming in Baldur's Gate 3.

Quote from Wawgster >>

The range of the sound is only within the 5ft cube, so unless a creature enters that 5ft cube they would not hear any sounds, blindsight, echolocation or otherwise.

 

 

Beyond 20

 

 

 

 

 

 Mmm. That's not how that works.

Improved Minor Illusion (School of Illusion, L2) ideas:

Pretend to summon something:

• The crate is roaring like it contains a lion. Stay the **** away...
• A deep purple summoning circle, with a demonic laugh emanating from within, rapidly increasing in volume.
• A floating skull that screams (you can create a stationary skull in mid-air) 
• An enormous black egg arising from the ground, with cracks shot through the shell and the muffled sounds of an immense creature within
• A sudden mound of broken earth with sounds of furious digging coming from beneath
• Bigby's Interposing But Entirely Illusory Hand, and a sonorous voice intoning, "DIRECT ME, MASTER, WHOM TO CRUSH!
• A magical-looking door that shows up against a wall, with insanely loud banging and roaring coming from the other side, and the door begins to splinter/crumble.

Reinforcements/Unseen Allies

• A small bush to hide behind and the sound of approaching reinforcements.
• A "statue" of an archer  (at the far end of your range so a perception check is unnecessary) and the thwip sound of an arrow right by someone's ear.
• A scream of "Medusa!" and the image of a stone statue, followed by sounds of hissing.
• Muddy footprints that appear ostentatiously, either 10' distant with the sounds of spellcasting or next to the enemy with the ringing of a sword being drawn, as though there's an invisible enemy there.

Profit now, pay later

• I throw illusionary gold on the table and make it clang.
• Steal stuff by creating an exact image over an item on a table, create a sound to divert attention, pilfer the item.

Divine intervention

• A symbol of a deity plus a projected voice? Like the 'burning bush' from the old testament.

Mislead pursuers

• You come to a fork in the dungeon while being pursued: create the illusion of a rock face camouflaging one tunnel and the sound of footsteps going down the other tunnel. Likewise: duck into a door or an alcove and camoflauge the door while sending the sound of footsteps down the hall.

Cover/Area Denial

• A rippling wall of maggots that squelches and burbles
• A wall of green briars with sticky crimson thorns, whispering, "Closer, come closer, my sweet!" in a susurrus like a breeze.
• Fake locks/chains to deter entry/attempted entry + alarm sounds.

Interrupt line of sight or spellcasting

• Enemy enchanter has your barbarian under hypnotic gaze. Put a bag over his head and create a loud ringing sound so he can no longer see nor hear the enchanter. Dismiss it.

Help your allies bluff

• Enhance the effect of a party member's action: ready an action to make the floor crack when the barbarian lands his charging leap attack, surround the caster with sparks to create a more obvious/powerful looking shield.

   

Do I need to have heard the voice previously to use it. Could I impersonate the mayor of the town we are in if I haven't met them or would I need to hear the voice first?

Could you use this cantrip to make a 5 foot cube of magical darkness or blackout a space above you to make a small section of darkness/dim light? 

No. (@BruceBadBack)

After further consideration I know that making a small section of magical darkness is beyond the ability of this cantrip, but it says that you can create an image of an object meaning it interacts with light specificity is able to absorb and bounce light back. So you should theoretically be able to make a dense mass of dark clouds around you/above you to make a pocket of darkness. This might seem pointless until you realize that the way of shadows monk can teleport from one spot of dim light/ darkness to another, meaning you could essentially throw a magic “smoke bomb” and vanish from sight.

Reminder: this spell can't create creatures, only objects. So no creating an illusion of a wolf or a duplicate of yourself. etc.

Could I use this to make a kind of "VR bubble" around a person so that, for as long as they're within the area, it looks like they're somewhere else? For example, if I want to trick them into think they teleported into another plane, could I put a 5' x 5' x 5' cube around their body that, from the inside, looks like a hellscape?

Combine this with Silent Image. SI provides the visual element, MI provides the sound. You could project pretty much anything you wanted, if it weren't too big.

Quote from Tyranthraxes >>

Casting Spellword is:

Imaginarium Mentalus

There's no verbal component.

You were not looking at this correctly.

For anyone confused, an easier example: Every human has a different voice. If a person shouts into a cave, they will recognize their own echo. Even if five people shout into a cave at the same time, they will recognize their own echoes apart from each other and other noises.

Bats go further than this. They don't just hear random sounds and go "Yep, something is over there!" Because that isn't echolocation, that is hearing. A bat makes a unique clicking noise, which is then echoed back to them off objects to tell distance and size. The reason that bats don't fly around in confused circles in a swarm is that they all have their own unique sound which they are listening for, or the clicks of all the other bats reflecting off each other would confuse them.

In other words, to convince a swarm of bats, or any echolocation creature, that there is an object that an object is there, you have to repeat their exact sounds. A random sound won't do, just like bats don't fly away from wind or distant bird calls. If there are fifty unique bats, you need to somehow figure out each of their clicks within about a second, before you have to repeat the sound. Any sort of echo-making, in general, has to be very skilled, or a high DC, to convince something it is hearing its own voice.

Could this be used to create moving images?

Step 1: Play a character under 5 ft tall (in my case, a halfling sorcerer).
Step 2: Take the Minor Illusion cantrip (or get it for free if you choose to play a forest gnome).
Step 3: Use MI to create a copy of yourself.
Step 4: Enemies now have to waste an action to find the real you or take a guess.
Step 5: Profit

That is, if the DM allows it. If I were DMing, I would totally allow this, as it doesn't really have any restrictions on what you can have the image be, and it seems a lot of people treat this like a miniature Silent Image anyways.

Quote from CrookedBeaker >>

Step 1: Play a character under 5 ft tall (in my case, a halfling sorcerer).
Step 2: Take the Minor Illusion cantrip (or get it for free if you choose to play a forest gnome).
Step 3: Use MI to create a copy of yourself.
Step 4: Enemies now have to waste an action to find the real you or take a guess.
Step 5: Profit

That is, if the DM allows it. If I were DMing, I would totally allow this, as it doesn't really have any restrictions on what you can have the image be, and it seems a lot of people treat this like a miniature Silent Image anyways.

 You can't create images of people, only objects.

I Can't think of a reason it couldn't, I imagine a  bumblee transformer kind of mash up of various voices they have heard. 

Quote from WeirdCharacters >>

Could this be used to create moving images?

 I would say no, because Silent Image specifically says it can do that, and this doesn't. It's a cantrip after all.

Quote from AnselMerric

You can't create images of people, only objects.

 True. But a life-sized wax dummy that looks just like you is an object. :)

Note that you can create an illusion taller than 5 ft as nothing in the rules says that the cube area of effect has to lie flat on the ground. Think of a cube standing on just one corner, you now have a maximum height of 8.6 ft (the space diagonal is d= length of cube side times square root 3). Of course, this would be just a thin, invisible line.  But at 6 ft height there‘s enough width for a human statue to fit, even a door should be possible.

The spell does not have a verbal component. Not that you can't say something for flavor.