Question:

Why can I hear high frequency noise when charging my device wirelessly?

Answer :

As the wireless charger using WPC(Wireless Power Consortium) Qi method carry the power communication packets in bands within an audible frequency of 1~2Hz when charging, so high frequency sounds may be heard slightly in quiet places.

While charging wirelessly, if a thick cover is attached with device or the device isn�t placed on center of charger, or in fast charging condition, the amplitude of the charging power increases so high frequency sounds may also increase.

Some chargers with heat-resistant FANs may be hard to hear due to the sound of the FAN running, but this can appear on not only existing previous wireless chargers but also third-party wireless chargers.

This is a common phenomenon that may appear by charging method and it�s not device defect.

Terms:

WPC - Wireless Power Consortium

Qi - A wireless charging standard developed by the Wireless Power Consortium

Audible frequency - The range of sound frequencies humans can hear (typically 20 Hz to 20 kHz)

Amplitude - The strength or magnitude of a wave or signal

Heat-resistant fan - A fan designed to operate at higher temperatures without malfunctioning

Third-party wireless chargers - Wireless chargers made by companies other than the original equipment manufacturer