Is it normal to hear voices while using the hair dryer?

I am not a scientist, but basically,what I think happens is your brain tries to make sense of stimuli, like sights and sounds and sometimes, in the case of a hair dryer, it tries to take the whining and noise and find patterns that can sound like speech. It's why people see faces in marbled tile or clouds and why you might see images in dark rooms even though there's nothing there. Your brain is just trying to deal with unfamiliar, incomplete, or incoherent information. Should the hair dryer start telling you to do things, then you might want to seek professional help.

Ever since I can remember I have always heard music when I have the bathroom fan on or an aircon or hairdryer .. occasionally it will be people talking instead , but have always seemed to sound panicked, desperate or scared. Never can make out the words just the tone of voices.. but with the music when I was early teens I used to just assume the exhaust fan somehow picked up music that was playing outside because it was always so clear and always different songs / genres .. some I’ve heard before and other completely new .

You could possibly be a "receiver", whereby you have extra sensory perception. Since you nor only hear voices when your hair dryer is on but also at night.
You should do more research on this.

What sunhawke said. Its an interesting phenomena, what is happening is that your mind it trying to make sense of the white noise so it distinguishes voices. You can read about it online; I first learned about it bc TAPS (on Ghost Hunters tv show) have used this to debunk several "hauntings." Fans & tv static can have the same effect. Think of it like an optical illusion, but for your hearing!

There's a term for this and it's annoying me that I can't remember the technical name. I used to know it.

My extractor fan duct in the bathroom is about 100 feet long because of where I live and when the wind is at a certain angle, it causes the same effect. It sounds like conversations are being had in there but I can't tell what they're saying. I had it in the bath overflow in my last place too. It was so strong, I wrote a story about it.

And I've just remembered what it's called. Auditory Pareidolia. It's a well-known effect. It happens because the brain is always trying to make some sense of what it is experiencing. There are visual effects that occur along similar lines.

I hear voices all the time while using a hair dryer but it's always my voice because I'm speaking into it to make my voice sound all funky.

It's white noise. It's normal.