A permit hereunder may be revoked if the amplified sound or noise emission constitutes a loud and raucous noise which is offensive to those in reasonable proximity to the amplified noise or sound or which loud and raucous noise is an unreasonable invasion of the privacy of those who reside in or occupy premises contiguous to the area in which the sound or noise is emitted. A permit hereunder may also be revoked if the emission of amplified sound or noise constitutes an impediment to the safe, orderly and free flow of pedestrian or vehicular traffic on the public street or sidewalk; provided, that no permit hereunder shall be revoked until request to lower the volume of noise or sound emission to a reasonable level has been made by an appropriate public official, and such request has been refused or only partially complied with.