1. Kate is listening to music with headsets on a smart phone.
2. Kate is listening to music with headphones connected to a smart phone.
3. Kate is listening to music wearing headphone attached to a smart phone.
(Are the sentences grammatical? Would you correct errors? Thank you.)
1 would be correct if you use the singular form: "headset."
2 is correct.
3 would be correct if you use the plural form: "headphones."
(A headset is made up of headphones ... but not vice versa!)
Also in #1, the word "a" needs to occur before "headset."