I went to the doctor and told him I had a ringing in my ears.

This joke gets its comedic power from a classic play on words, transforming a common medical complaint into an absurd misunderstanding. When someone says they have a "ringing in their ears," it's almost universally understood to mean tinnitus, an internal sensation of sound. The humor springs from the doctor's deliberate, literal interpretation of "ringing" as the sound of a telephone, leading to a perfectly unhelpful yet hilarious piece of advice.

The real-world context behind the setup is simple: tinnitus is a very common condition, often described as ringing, buzzing, or hissing, and it can be quite bothersome. This relatability makes the initial situation familiar to many. However, the joke quickly veers into the realm of comedic license, where medical professionals in humor often become figures for exaggerated literalism or bizarre solutions, much to our amusement.

Ultimately, the punchline works because it completely subverts expectations. Instead of offering a medical solution to a medical problem, the doctor offers a domestic one, highlighting the silly side of language and the unexpected places humor can hide. It's the delightful clash between the serious implication of the setup and the utterly nonsensical advice that makes this simple doctor joke a winner.