Many people believe that the performance standard for multi-family is too low. Frankly, achieving code does not mean achieving quite living. The range of the test excludes some important frequencies well below 100 Hertz. Frequencies as low as 25 Hertz are quite noticeable and some times quite bothersome. Performing to a "50" does not mean hearing nothing from the neighbors. As the multi-family sits in a lull during this market downturn, it is safe to say that noise is something that should be revisited, especially vibration noise.
A number of excellent acoustical consultants have pushed for a change in the code requirements. Some have asked that the testing metric be divided so that a performance is measured separately in the high and low frequencies. Many have called for an enhancement of the requirement calling for higher performance levels. Cities such as those in Northern California and in Chicago have required STC and IIC standards that exceed the UBC levels. Needless to say, quiet living is still at the top of most owners concerns and will remain there until the last shoe drops and no one hears it!!
In other complaints about our noise standards, there is an industry discussion about how the tapping machine doesn't reflect the type of noise that an individual makes when walking. This is absolutely true from a reflective noise standpoint. What we create on the topside sounds nothing like me walking, or a woman in high heels. The tapping machine does sound like a herd of horses in the receiving room and the noise from me walking, or the tapping machine is not much different so changing this metric isn't the most important modification. In other countries there is a recognition that low frequencies are the culprit more than it is in North America.
Changing the standard ASTM tests for E90 and E492 doesn't seem necessary. Changing the standards that we shoot for does.