A sound at another connected fixture is useful evidence that the drainage system needs consideration beyond the disposer itself. Note where it occurs and whether it happens with ordinary sink water while the motor is off.
What the observation tells you
Do not keep running water to reproduce a gurgle if drainage is slow or water is rising. The sound alone cannot identify a blockage location or prove that an air-admittance component is faulty. Avoid opening pipework or changing fittings from a remote diagnosis.
A useful next step
Tell the person assessing the problem which fixtures are affected. A broader drainage investigation may be needed before any appliance repair can be meaningfully specified.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.