Is That Noise Inaudible?

In a 2015 case before the NYC Board of Standards and Appeals, our residential clients heard weights dropping in the downstairs gym. The gym's acoustic consultant said that not only did he not hear the bangs, but they were quieter than some study's "threshold of hearing", implying that Al Fierstein and the residents were all lying.

An unreasonable noise does not necessarily have to be louder than some number.

If someone says that you can't hear something when you clearly can, maybe they have defective hearing, or maybe they are twisting the facts.

So how can a noise below the "threshold of hearing" be heard?

In this video testimony, you can hear the consultant and the gym's lawyer try to convince the BSA that there was no audible sound. Al Fierstein of Acoustilog then explains to the Board members the full story.

The study's "threshold of hearing" was the median threshold; the 50% point. This means that half of the tested subjects had more sensitive hearing than that; 16% of them had hearing that was more than 6 decibels (34%) more sensitive.
The "threshold of hearing", was measured with a "pure tone": a sound consisting of a single frequency, like an organ bass note. The weight drops produce many frequencies simultaneously, all of which are combined in our auditory system, making it sound louder.
Most importantly, the "threshold of hearing" used a test where the sound level is raised gradually in the subject's headphones until it can just be heard. But the sudden impulse caused by a dropped barbell is much more attention-getting and has a lower threshold.

Watch the Video

Opposing Testimony
Alan Fierstein's Testimony