In article uVOlb.2980$275.8970@attbi_s53, Frederick Wilson
wrote:
From what I remember, most suggested putting cotton in the ears and then one
of those head caps that have ear covers and ties under the chin.

Also, you can cut foam earplugs in half-, quarter-, etc lengthwise to
reduce the volume to fit in the ear canal.
Infants are suffiently small that you would be better off using a soft
foam pad under the earflaps of the hat mentioned above.
Do a google search of past newsgroup postings. Much has been written on
this subject.