How does the playback of cassette tapes affect the magnetic properties of the tape?

Some additional sentences to explain the rephrased question are:

Cassette tapes store audio information as patterns of magnetic domains on a thin film of ferromagnetic material. When the tape is played, it passes through a coil that acts as a transducer, converting the magnetic fluctuations into electric signals that can be amplified and reproduced as sound. However, the coil also produces its own mag