More often than not, audio quality issues are isolated to the handset or handset configuration, some common causes include..
- Handset volume being turned up too high
- Microphone sensitivity being turned up too high
- Faulty headsets or headset cables
- Incorrectly connected cables (partially inserted, with pins or terminals bridging)
- Turn down the volume on the handset
- Reduce the microphone sensitivity on the handset
- Disconnect any headsets or other audio peripherals connected to the handset
- Ensure the handset cable is connected properly at both ends (base of the handset and back of the phone)
- Try a different phone and see if the same problem occurs - if the fault is isolated to a particular phone - then that device may be faulty
Note 1: The issue occurring on multiple handsets does not exclude the above troubleshooting steps. It's quite common that a set of handsets in the same office will all have high volume levels, or the issues with faulting headsets or cables.
Note 2: These causes generally only apply when the issue affects both inbound and outbound calls to multiple or all destinations.
If none of the above are found to be the cause, or if the issue only affects particular calls (eg. only inbound calls, or only calls to a particular number, or seemingly random) then a log of calls should be collected using the Call Problem Reporting Sheet.