There is nothing in the Spec's about a speaker.  Except for a rare few, Desktops do not have built in speakers.  Some "All in One's" have speakers.

Here is the link to the Dell Spec's.

https://topics-cdn.dell.com/pdf/vostro-3670-desktop_owners-manual3_en-us.pdf

you posted to DELL DESKTOPS , IS IT?

the green rear 3.5mm jack on the rear, (LINE) runs headphones or powered speakers.(or ear buds)

what do you expect from them (POST beep errors) or music/voice..  tell what is expected first then solutions are easy. x10 more.

desktop evolution 101 (those funky beeps)

The first even 1981 IBM a 1.5" speaker inside, A NOISE maker, or BEEP, it never does voice or music, ever.

we'd call that a POST error sonic transducer?

the Piezo-electric noise makers next then some had the above still.. FOR POST error beeps.

My dell if overheat plays a TUNE melody, just 1,< crude, like,  is really just fast beeps, and odd has heck...

then later PC when silent or is optional for beeps,  many business PCs 100's per floor HATE BEEPS,  yah!

BEEPS now covered,

better are silent  POST errors with 4 digit LED strip for POST errors, far far better is silent PC..

Thanks for your precoius replies.

Every PC I have owned since DOS1.8 has had a small internal speaker. You could hear sounds like the Windows tone when you start Windows. Ive never see it listed. Does my Dell Vostro 3670 have one because it sure doesnt make any sounds