Asklemmy

Looks like one of those recorded message things you find inside greeting cards - the glob of stuff below the black epoxy blob (the ic), looks like a badly corroded button.

Can try cleaning the button up a bit, or removing it entirely, and bridge the connections beneath it.

I've designed similar devices.

The epoxy blob likely plays factory-set chiptunes out the piezo element.

It's unlikely to play voices, just tones. The ones that record arbitrary audio use specific ICs from China, none of which I see there. Also those work with small but standard speakers, not generally piezo elements.

As a small window into how these are designed, a lot of the engineering goes into reducing power consumption and parts count. The button might for example drop the pin of an MCU low to trigger an interrupt that wakes it from deep sleep. Then it plays a tune stored in eeprom (more common) or internal flash (less common). Usually the chips are one-time-programmable and cost under 0.10$!

There is no microchip which means it can't be a listening/recording device. Seeing as the circuit is very simple, my bets would be on it being some kind of oscillator, as I can't see what else you could build using only two components. An oscillator circuit produces a single unchanging, constant tone. I know that circuits making high pitched tones are used to repel moles (in gardens) and teenagers (in shopping centers). I guess they could be used to repel, like, moths as well?

Edit: didn't notice the blank epoxy blob. Yeah that's a microchip

From the other comments, it could be a novelty hat that speaks or makes a sound effect when the button is pressed. I’m curious to find out what the original sound would have been!

Quick question: Where does the battery go? Is it the corroded part in the first internals image, or was that the button?

If I had to guess it's a speaker of some kind.

Can you post what's on the label of the cap? I think that will help tell us who made the item. I couldn't find anything searching the number on the board with the company name on the plastic.

Since it says Marines, I'm thinking this is some novelty item that might play Sousa's Semper Fidelis.

Is this one of those mosquito repellent noise makers?