Hi,during your travel in flight from UK to America-during sudden changes in outside atmospheric pressure during the flight going up and landing,the middle ear pressure may not be able to equalize with the outside atmospheric pressure-leading to negative middle ear pressure-this may lead to mild retraction to your ear drum or mild fluid retention in your middle ear which may lead to your ear squeak (hearing high pitched sounds). You may find relief by taking Anti-histaminics(like Cetrizine),Oral Decongestant(like containing phenylephrine),Nasal Decongestants. Also do Valsalva Maneuvre(breathe in deeply,then close your nose and mouth and then blow your mouth)-this will help to open your eustachian tube if it is blocked(it is a tube which connects middle ear with the nose and is responsible for equalization of middle ear pressure with the outside atmospheric pressure)-this might lead to equalization of your middle ear pressure with the outside atmospheric pressure. Do steam inhalation.Avoid cold food,dust and other pollutants. Even by following the above measures,if still your complain does not reduce,then it wuld be advisable to consult an Otolaryngologist Doctor. Hope this answers your question.Take care.