Finding the original inventor of sound masking isn’t easy. Do we define sound masking as any sound that masks other sounds? If so, then we have to go back to natural sounds like water flow. I can imagine a pair of early humans standing next to a waterfall talking about something secret! But I don’t think that tells us who invented sound masking.

Since we’re talking about modern technology, we need to work out whether sound masking can be conflated with white noise.

Who invented white noise?

Even the answer to this question is somewhat controversial. Could it be the inventor of the radio, Guglielmo Marconi? White noise is in effect the sound of a detuned radio after all. If so, that takes us back to in 1896—or 1897 if we count Nikola Tesla (I told you, it’s controversial!).

But if we’re talking about commercial white noise machines, Marpac claims to have invented the first “white noise” machine. In 1962, Jim Buckwalter discovered that the whirring of a fan motor helped his wife sleep and sound conditioners were born.

Others claim that Gian Lorenzo Bernini, a 17th century artist, invented a “white noise” machine out of paper and wood for insomniac Pope Clement IX, almost three hundred years earlier!

Again, this is if you conflate white noise with sound masking. The answer to who invented sound masking in particular requires a little more nuance. The creation of sound masking was not simply a sleep aid or a background noise. It heralded a new era in office productivity and speech privacy.

First patents

Upon searching the US patents database, I discovered that the first patent was awarded to Canadian Theodore Wildi in 1975 for his “Sound Masking Method and System”. It was described as follows:

A method and apparatus for masking sound comprising, receiving in an area an original sound signal which has to be masked. The original sound signal is then delayed to produce a time-delayed signal. The time-delayed signal is amplified and emitted outside the said area whereby the original sound signal will combine with the amplified time-delayed signal to produce a substantially unintelligible sound outside the said area.

However, upon reading the patent itself, there is sufficient “prior art”, as it’s called in patent-language, to suggest Wildi wasn’t the first. Unfortunately, there are no earlier patents specific to sound masking to shed further light on the subject. All we know for sure is that there were earlier sound masking systems for Wildi to use for his patent.

Soon after, in 1976, Ludwig W. Sepmeyer patented his “Background Sound System And Apparatus For Masking Speech” which reads more like how modern masking systems operate.

So, who invented sound masking?

I suspect we will never really know who invented sound masking. None of the patents from the 1970s prevented modern sound masking manufacturers designing and selling their systems. Probably because the sound masking systems can be created and implemented quite creatively, without violating any patents.

As the technology evolves, there is nothing new under the sun. This truth is at the forefront of “soundscape” a newer masking technology. Running rivers, rain, and waterfalls introduce a natural masking sound borrowed straight from the original.