The Purpose of the sponge is mostly comfort and it protects the earpiece from dirt and earwax. I don't think there are any risks that you need to be concerned about, just make sure that you keep the earphones clean.
Please let me know if you have any further questions
The information provided does not constitute a diagnosis of your condition. You should consult a medical practitioner or other appropriate health care professional for a physical exmanication, diagnosis and formal
advice. Health24 and the expert accept no responsibility or liability for any damage or personal harm you may suffer resulting from making use of this content.