A portable electronic device and personal hands-free accessory are provided. The personal hands free accessory includes at least one electro-acoustic speaker, and at least one microphone that receives ambient sound and converts the ambient sound to an ambient sound signal. Included among the portable electronic device and the personal hands-free accessory are a processing circuit, the processing circuit including circuitry that combines an audio signal from the portable electronic device with the ambient sound signal from the at least one microphone to produce a combined audio signal provided to the at least one speaker such that the at least one speaker reproduces the ambient sound in combination with audio from the audio signal; event detecting circuitry for detecting an occurrence of a predefined event; and disabling circuitry for substantially disabling the reproduction of the ambient sound signal by the at least one speaker based upon the detected occurrence of the predefined event, while still permitting the reproduction of the audio signal.