A North American vehicle OEM wanted to establish acceptability/annoyance thresholds for the sounds generated by the exhaust system after the engine is shut off. These are transient, ping-popping type of sounds and are caused by the metal reacting to the temperature gradient while the exhaust cools down. The vehicle OEM recorded all data following their test procedure, and supplied the data to Sound Answers for the analysis. A formal jury test was designed and utilized by Sound Answers to determine customer reaction to these sounds. The results of the jury test were used to develop a preference equation that predicts the customer annoyance from key objective attributes of measured data.