07/07/2017
Broadband Isolation Study Proves
Sensaphonics Silicone Superiority
Sensaphonics users are well aware of the superb isolation, seal, and comfort that our proprietary soft silicone earpieces provide. But how much true broadband isolation are you getting? Isolation varies with frequency, materials, and fit, so the single-number isolation number shown in specifications can be misleading. So we contracted an independent psychoacoustics laboratory to perform a scientific study of exactly how well our earpieces isolate across all key frequencies.
The isolation study was conducted by Michael & Associates of State College, PA. All study participants wore custom-fit Sensaphonics earpieces for three separate live listening tests, with the lab measuring isolation from ambient noise across 9 key frequencies from 125 Hz to 8 kHz. Notable results include group attenuation figures as high as 45.5 dB at 8 kHz. Critically, the study also documented a minimum isolation of 29.6 dB in the difficult-to-block low frequencies. All tests were performed in accordance with American National Standards Institute specifications (ANSI S3.19-1974).
The full results are summarized in this chart:
broadband isolation study
By publishing these independent test lab results, Sensaphonics is raising the bar for transparency and truth in isolation specifications for IEMs.
âIsolation is the key to being able to monitor clearly at safer levels with IEMs. Without it, any promise of hearing health benefits is meaningless," notes Dr. Michael Santucci, Sensaphonics President. "Until now, no IEM company has documented the science behind their isolation specs. We're all about the science, and this independent study proves that our proprietary soft silicone formula produces the most isolating in-ear monitors on the market.â
Why broadband isolation is key
The reason isolation is so important is basic acoustics: By blocking outside sound, the noise floor is reduced, improving the signal-to-noise (S/N) ratio, allowing the user to hear the IEM monitor mix more clearly at lower, safer listening levels. With our proprietary soft silicone formula that flexes with the ear canal to maintain a full seal (and thus, full bass response), Sensaphonics IEMs create a quieter listening environment that allows the accuracy of the audio to shine. The hollow plastic used in most earpieces just doesn't measure up.
Details within the Michael & Associates study were revealing, with an overall average was 34 dB of attenuation across the 9 test frequencies. Frequencies above 1,000 Hz averaged an outstanding 41.8 dB of isolation, from 37.3 at 2 kHz to 45.5 dB at 8 kHz. As expected, low frequencies were the most difficult to block, yet still achieved an average of 31.6 dB of isolation across the range. The study's accuracy is validated by the small variance across all measurements, with standard deviations ranging from just 3.2 to 4.6 dB. This indicates excellent consistency despite the inevitable variation in individual subjectsâ fit and insertion technique.
âWe used to work in hard acrylic back in the mid-90s, but as an audiologist, I knew that soft silicone would make a better product,â notes Dr. Santucci. âThis independent scientific study proves it. Acrylic may be cheaper and easier to manufacture, but it just doesnât provide the isolation, comfort, and seal of our proprietary silicone formula. Thatâs why you never see hard materials used in earplugs.â
A focus on health-conscious design and innovation is Sensaphonicsâ signature contribution to music industry. By applying our deep knowledge of hearing loss prevention techniques and consulting with touring musicians and sound engineers, our products address their monitoring needs without the hearing health risks inherent in massive multi-driver designs.
âWe have always known that our soft silicone formula was the most isolating, but that fact has gotten lost in a sea of undocumented claims," notes Santucci. "This independent scientific study provides the first truly transparent explanation of how well our soft silicone IEMs isolate across all frequencies, and how that translates into an in-ear experience that no other company can match.â