I got your attention, didn’t I? When I am talking about hearing aids and SIN, I am not talking about the Biblical definition of disobedience to God, I am referring to an acronym S-I-N which stands for “Signal in Noise.” The signal is always the original sound we are trying to hear. A faithful, accurate reproduction of original signals has been the pursuit of research and development ever since Thomas Edision invented his cylinder recording device. We probably all remember how scratchy those historical recordings were.

If we record a human voice reciting the alphabet, the original is what we hear them say with our ears. If that is recorded and played back, there will always be a slight variation from the original. All sounds could be recorded and displayed on an oscilloscope. This is a machine that can display sound waves as a graph by connecting a microphone to it. The microphone converts sound energy into electrical signals, which the oscilloscope then shows on its screen. The graph shows the amplitude of the sound on the vertical axis and time on the horizontal axis. The human voice recorded compared to a recording of that human voice or a recording of the recording would show slight changes in the graphs.

Audio scientists sought from the early days to produce an accurate sound or sound that had fidelity or faithfulness to the original signal/sound(s). You may remember audio sound systems from the 1960-70s that advertised, “high-fidelity.” They were saying their equipment was as close to the original sound as possible. Digital sound reproduction moves us forward to tremendous quality in recording capabilities, but oscilloscopes still show a very small variance from the original signal.

The hearing aid industry has followed and, at times, led the audio reproduction industry towards sound quality. The goal with hearing aids is not only a faithful reproduction of the original sound but how that sound or signal is heard when it competes with background noise. The SIN, signal in noise ratio, is an ever-present attempt to make the speech more intelligible against the background noise. Digital hearing aids have taken leaps and bounds in the last 10 years in preserving the original sound of voices and helping users hear voices better in clutter or background noise.

By the way, that is why a patient’s voice also sounds different to them as they hear their voice through the hearing aids. The reproduction of the sound is slightly different than what they hear as they speak. Like hearing your voice on a sound recording for the first time. Signal-to-Noise Ratio noise (SIN) is an important factor when choosing the level of technology in hearing aids.

If you have hearing loss, call a hearing care professional soon to schedule a test. The professional will guide you as to your results, needs and budget.

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Jeffrey L. Bayliff is owner of Hear the Birds Hearing Aid Centers in Lock Haven and State College.