You talk about a weekend trip, then an ad for flights appears. You mention a new coffee machine, then your feed is full of espresso gear. It feels spooky. Most of the time it is not the microphone. It is prediction based on signals you already leak, clicks, follows, searches, location, purchases, and your friends.
This guide explains why this happens, how the prediction engine works, and what you can do to reduce it. We will keep it technical and clear so a non technical reader can follow every step.
Your phone is not psychic, it is predictive. Many small signals add up to a strong guess.
Ads and feed ranking do not need audio. They use events from many places. When you browse a shop, an invisible tag logs a view. When you install an app, its SDK reports open and purchase events. Location comes from your phone, or from a partner app that has location. Data brokers sell segments like new parent or frequent traveler.
Think of a model that learns what people with similar behavior clicked and bought. If people like you recently searched for flights, watched beach videos, and looked at luggage, the model raises the score for travel ads on your feed. No audio is needed. The match comes from patterns.
Timing tricks the brain. You talk about a product, then you notice a similar ad that would have appeared anyway. Conversation and ad are both caused by the same life event, a move, a trip, a hobby. Social and location graphs add another boost, you and a friend shop in the same places and follow the same accounts, so your feeds align.
Large platforms state that they do not listen to conversations to target ads. Voice assistants listen for wake words. Some small apps have abused permissions in the past. On iOS and Android you can see when the mic is active. You can also revoke mic access for any app that does not need it.
Your phone is not magic. It is math and data. Once you know the system, you can shape how much it knows and how much it shows.
Set a timer and do these quick changes. Small steps reduce the creep without breaking your apps.