What needs to be clarified
The task is to identify observations and measurements that can test the connection with specific equipment, rather than merely describe a subjective impression.
Materials to prepare
- A diary of when and how the hum occurs
- Information about repairs and equipment operating modes
- Existing measurement records and room layout
What to compare
- Compare recurrence with available information on system operation.
- Agree on comparable conditions for observation and checking possible sources.
- Separate audible noise, structural vibration and information still missing.
Possible outcome of the analysis
The result may be an examination programme and, after agreed measurements, a document describing conditions, observations and reasoned answers.
Limits of the conclusions
A phone recording helps describe the complaint but does not replace necessary instrumental examination or independently establish the source.