Abstract: An acoustic barrier structure can include a support structure that defines a plurality of cells, a weight attached to the support structure, and at least one resonant membrane covering one of the plurality of cells. The at least one resonant membrane can comprise at least one weight. The at least one resonant membrane can have an anti-resonant frequency and the support structure with the weight can provide wide frequency band gaps between odd resonance modes while suppressing structure-membrane coupled modes to enable the anti-resonance of the at least one resonant membrane.

Abstract: A method and system for providing customer service evaluations to entities seeking testing of their employees' customer service skills. The method automatically records a mystery shopper's conversation with a targeted employee and attaches a corresponding voice file to a shopping report which can later be completed by the shopper. The mystery shopper first learns of a mystery shopping assignment and then calls a telephone recording system. The shopper is prompted to enter his or her user ID, a call code related to the shopping assignment, and the phone number of the target company. The telephone recording system then connects the shopper to the target company and automatically records the shopper's conversation with an employee of the company. Once the mystery shopper completes the assignment and hangs up, the recording is automatically converted to a voice file and transmitted to a web reporting system along with the call code.