Method for simultaneously operating a loudspeaker assembly in a loudspeaker function and in a microphone function, and loudspeaker assembly

A method for simultaneously operating a loudspeaker assembly in a loudspeaker mode and in a microphone mode, comprising:

• operating the loudspeaker assembly, the loudspeaker assembly comprising:
• a coil, which is movably mounted in a magnetic field of a magnet that produces a magnetic flux density, the coil having an effective length in the magnetic field,
• a diaphragm having an area, which is mechanically coupled to the coil, and
• an external sound pressure acting on the diaphragm in the microphone mode;
• and
• determining the external sound pressure acting on the diaphragm in the microphone mode by:
• setting a first calibration state, in which the external sound pressure on the diaphragm is equal to zero, and measuring a current flowing into the coil and a voltage dropping across the coil,
• determining a first transfer function based on the measured current and voltage from the first calibration state,
• setting a second calibration state in which movement of the diaphragm is suppressed, and measuring a current flowing into the coil and a voltage dropping across the coil,
• determining a second transfer function based on the measured current and voltage from the second calibration state,
• measuring the current flowing through the coil and the voltage dropping across the coil during a normal operation, and
• calculating the external sound pressure on the diaphragm using the magnetic flux density, the effective length of the coil in the magnetic field of the magnet, the first transfer function, the second transfer function, the area of the diaphragm, the current and voltage measured during the normal operation.