Q: Iphone 4 headphone jack not recognising headphones insertion

so recently I having problems with my iPhone 4 headphone jack, I have been trying to insert headphones into my iPhone and when I do it doesnt recognise the headphones being inserted as when I press the volume up/down button it shows volume and nit headphones, now I know this is not a problem with the headphones being used as I have used various ones to insert to my phone and I am really unsure why this problem occurs, could someone assist me here, thank you