Toddlers are new to the world and are constantly exploring new things. During this period they may try to communicate or express themselves by certain actions or gestures and covering their hands over their ears is one of them. Most of the time, these actions are innocuous. Some possible reasons for this include:
1. Sensitivity to sound - if your environment is noisy, certain sound may be too loud or cause discomfort to your toddler. Sometimes, the increased sensitivity to sound and other stimuli in the environment may be due to Autism Disorders. To overcome this, the child may cover both ears to keep himself/herself comfortable. However, a child with autism are likely to exhibit other problems such as difficulty in maintaining eye contact or socializing with other children.
2. Ear infections - A child with an ear infection may have cover his/her ears because of pain, discomfort or have a blocked ear. Other common symptoms indicative of a possible ear infection include irritability, poor feeding and fever. Ear infections are more often one sided rather than both sides. It is also possible for toddlers to insert foreign bodies (e.g. beads) in their ear canal, resulting in ear discomfort. Again this is usually more common in one ear.
3. Nervousness or fear - covering their ears may be a protective mechanism used by toddlers to make them feel "safe" or comfortable especially in crowded areas or when exposed to new experiences.
I would suggest visiting a general practitioner or a pediatrician for a general assessment first if this habbit has been persistent for a while or if you are worried. If there is troublesome ear infection or suspicion of hearing loss requiring the input of an ENT Specialist, he or she can refer accordingly. Some of the warning signs that this is more than just a coping mechanism include:
1. Behavioural issues, trouble socializing/interacting with others and delay in speech and language development (suggesting a possible Autism Disorder)
2. Ear pain (if the child is able to express this), irritability, poor feeding, fever or delayed in speech/language development (suggesting a possible ear infection)
Hope this helps and all the best.