It's "a pair of headphones" or simply "headphones". Since the noun "headphones" is always used in a plural form, we never use it with the article "a".
It's "a pair of headphones" or simply "headphones". Since the noun "headphones" only has a plural form, we never use it with the article "a".
A pair of headphones can be connected to multiple devices.
A headphones can be connected to multiple devices.
She likes wearing headphones during the race.
My wife bought a new pair of goggles yesterday.
We often use a possessive pronoun (my, your, his, her, our, etc.) to introduce these objects.
She can't find her headphones.
If you want to count them, you can say "two pairs of", "three pairs of", etc.
I have two pairs of headphones in my room.
You can also use other determiners for plural nouns, like "some", "any", "the", "these" (not "this"), etc.
These headphones are designed for mobile devices.
But use no determiner to talk about "headphones" in a general sense.
Headphones are typically marked with L and R.
Be also aware that plural nouns, like headphones, require a plural form of a verb, so we say "headphones are" (not "headphones is").
Where are my headphones?
Where is my headphones?