I believe that "digital trauma" was meant to convey sticking a finger in one's ear? However, it's common for other forms of trauma to precipitate otitis externa -- i.e. sticking a foreign body (Q-Tip, needle, toy, finger, etc.) into one's ear.
UWorld corroborates this (Step 2 - qid:15991):
"Otitis externa risk factors:
- Water exposure
- Trauma (eg, cotton swabs, ear candling)
- Foreign material (eg, hearing aid, headphones)
- Dermatologic conditions (eg, eczema, contact dermatitis)"
https://next.amboss.com/us/article/mj0VaT?utm_source=navbar&utm_medium=anki&utm_campaign=anki&utm_term=otitis%2Bexterna&guid=q%257C%252B%2528%2528y%252Aj~e&aid=298bfc66-b119-4c76-b7ef-8bfc7d192ab2&uid=ptfeLeLy0#Z33fb0a711e98001f215f1a4e90ddded7