Troubleshooting Audiometer Output Level Errors Before Calling for Service

The first step is to determine whether the error is channel-specific, transducer-specific, frequency-specific, or level-specific. Run the following isolation matrix before any further troubleshooting.

Switch the ear (left channel to right, right to left). If the error follows the ear assignment, the fault is in the channel. If the error follows the transducer, the fault is in the transducer or its cable. If the error is present at all frequencies and levels, the fault is likely in the amplifier chain or attenuator.

Supra-aural earphone cushions that are cracked, hardened, or flattened alter the acoustic seal and can produce apparent threshold shifts of 5–10 dB at low frequencies. Inspect the cushions visually and replace them at the first sign of deterioration.

Bone conduction vibrators are sensitive to physical impact. A vibrator that has been dropped will frequently show elevated output at high frequencies and reduced output at low frequencies. Listen to the bone vibrator directly against your fingertip — it should feel smooth and consistent across all test levels.

Intermittent output errors that come and go with physical movement of the headset cable are almost always caused by a broken internal conductor at the strain relief — either at the headset end or at the audiometer panel connector. Slowly flex the cable along its length while monitoring the output; a distinct crackle or intermittent drop identifies the fault location.

Corrosion on the panel-mount connector pins is common in high-humidity environments. Inspect the connector under magnification. Light corrosion can sometimes be cleaned with a contact cleaner spray, but if the corrosion has pitted the pin surface, connector replacement is required.

Stepped attenuators that skip levels, produce crackle when adjusted, or show non-linear output between adjacent dB steps indicate mechanical wear or contamination in the attenuator switch contacts. This is a common fault in instruments with high daily usage.

A non-linear attenuator is a calibration failure and the instrument must be removed from clinical use until serviced. Do not attempt to work around the fault by avoiding certain dB steps.

If the fault persists after substituting a known-good transducer and cable, the problem is almost certainly in the instrument body and requires a qualified service technician. Similarly, if the biological calibration shows a threshold shift greater than 10 dB, the instrument must be pulled from service immediately.

Document all troubleshooting steps taken before placing the service call. This information significantly reduces the technician's diagnostic time and may reduce your service invoice.