The chart below shows the differences between the OPN 1, 2 and 3. The S1, S2 and S3 have pretty much the same differences compared to their original OPN counterparts, so this chart can be applied to the S just the same. The S version primarily has the new feedback prevention technology compared to the original OPN, but otherwise are very similar in the other features.
You can see that the OPN 1 gives you a max noise removal of 9 dB, while the OPN 2 gives you a max noise removal of 5 dB. What does this mean? Take a look at the second screen below. It shows how the noise reduction works on the OPN 1, up to 9 dB. So effectively it removes most of the dark grey noise you see in the chart, and the only noise left is the little bit of light grey noise just around the red speech areas.
If you had bought the OPN 2, although it’s effectively the same device, they limit it in the software such that its max noise reduction is only 5 dB instead of 9 dB like with the OPN 1. So in the second illustration below, visualize an imaginary 5 dB line between the 3 dB and the 9 dB level. So the noise reduction is clipped to removing only up to 5 dB of noise, instead of up to the 9 dB of noise as seen. So the light grey areas around the red speech is not going to be as thin as you can see here, but is going to be up to 4 dB thicker. This means that the noise reduction between 3 dB and 5 dB is effectively the same between the OPN 1 and OPN 2, but the OPN 1, where and if necessary, can reduce the noise even further, for up to 9 dB.
Of course in the illustration below, they’re showing a hypothetical level of noise that is conveniently at 9 dB to make their point. But if the noise level had been 12 dB for example, then there’d still be 3 dB of noise left that even the OPN 1 can’t remove. By the same token, the OPN 2 left 7 dB of unremoved noise on the table.
On the other hand, if the situation is such that the noise level is only as high as 5 dB, then both the OPN 1 and OPN 2 will perform the same and reduce the same amount of noise because that’s all the noise there is. So the point is that whether the OPN 2 or the OPN 1 makes a difference in noise reduction to YOU or not depends largely on how often you find yourself in what kind of noisy situations. If you go to restaurants that is not super noisy and the noise is only up to 5 dB, then the OPN 2 will perform just as well as the OPN 1. But if you go often to places where the noise level is consistently and significantly higher than 5 dB, then the OPN 1 will outperform the OPN 2.
Some folks (and I hear even some audis) give the impression that too much noise reduction set for the OPN can be a bad thing. But this is not really true because as you can see in the example below, the OPN only applies the necessary amount of noise reduction dynamically, and never more. The NR setting is for Max value as needed, it doesn’t mean that it’s a constant NR value applied all the times.
It determines what is speech, then dynamically minimize the noise reduction during speech, and dynamically increase the noise reduction in between speech (but only enough to negate the amount of noise as much as possible), just like what you see in the illustration. And when speech stops, it actually restores the “noise” around you so preserve the “openness” of its open sound paradigm.
It can do this because it uses one mic to pick up the sound in front and the other mic to pick up the sounds from behind and on the sides. The later is modeled to be the noise source, while the earlier is modeled as the speech in front. It also has a speech detector, to identify when there’s speech in front and when there’s not. Once there is a “model” for the noise and a “model” for the speech, then it becomes easy (and effective) to subtract the noise from the speech as necessary, up to the max possible noise reduction value. This is why Active Noise Cancelling headphones are effective, because the noise and the main (streaming) content are from 2 separate sources, hence it’s easy to negate the noise source to preserve the desired source. The OPN takes a unique approach to separate the diffused speech + noise into 2 different sources so that they can manage the diffused noise removal more effectively, in a similar fashion as with ANC headphones.
@dcasey9991, I think the answer to your question is if you don’t go out to VERY noise restaurants often enough, the OPN 2 is probably good enough for you in terms of noise reduction. But keep in mind that Noise Reduction isn’t the only difference between the OPN S1 and OPN S2, look through the list to see what else is missing in the OPN S2 that may be important to you. But the Noise Reduction value is probably the most significant difference.
As to the situation where speech is not in front of you, then the noise reduction difference between the S1 and S2 probably won’t be much different to you. The NR is primarily applied to clarify the speech in front more than speech on the side of in the back. But the OPN overall will be an improvement compared to the Phonak 90s you have in terms of being able to hear the speech behind or on the sides better, simply because of the OPN open paradigm.
In terms of noise reduction impact on music, the value of the noise reduction level difference is primarily for front speech clarity, so if you use the built-in music program to listen to music, NR is disabled, so you will not hear much difference between the S1 and S2 for music. I think the Clear Dynamics feature may have an appreciable difference when listening to music. Fortunately it’s available in both the S1 and S2, so there’s no difference there, as long as you don’t go down to the S3 because Clear Dynamics is not available in the S3.
