Answer:
Encoding failure
Step-by-step explanation:
Encoding
This is simply defined as the processing of information into the individuals memory system. There are different Levels of Processing theory that serves as recall of information which is based on how deeply informations are processed, a theory by Craik and Lockhart.
Encoding Failure
This simply covers when an individual never attending to the information in the first instance. This can lead to Storage decay which is said to be the fading of information due to the lack of use and involves physical change in the brain.
The phone serves as an Interference which is another set of information that makes it hard to remember another set of information( the professor's lecture).