Effect of frequency compression on speech understanding


I have been using my KS8S for several months now, and am very happy with them. In another post I mentioned that the music program worked better for my understanding of speech than the Automatic program. One response was that this could be due to the fact that the Automatic program is often set up to compress or lower high frequencies and that could in fact degenerate your understanding of speech. I would like to hear other opinions on this, especially from audiologists or other hearing professionals.



Again, I was talking about level compression, not frequency compression. Although frequency compression is also something that can improve audibility of consonants while simultaneously introducing distortion, I was guessing that your music program was providing more linear gain.



Can you explain a little more about level compression vs. frequency compression? As a former radio announcer (circa 1961), I recall a piece of equipment we installed which suppressed sudden amplitude changes. Does this work something like that? I have noticed (it seems on all programs) that a sudden change (such as clearing my throat) seems to reduce the amplitude momentarily. In looking at the KS8 settings with Connexx Eight and Noahlink Wireless, I haven’t seen a setting for level compression.



Frequency compression is called Bandwidth Compression on the KS8. Your loss is not sloping so you may not benefit from it. It moves sounds to lower frequencies.

Mine slopes and I have dead regions so my first experience with it was like opening a new door of sounds.



No, the sudden impact noise reduction is a separate system. I’m not familiar with the costco software, but right were you do your basic fitting adjustments across frequencies there are controls for soft, medium and loud. If the number is different at these different levels you are either compressing or expanding the sound (providing a different amount of gain for different levels of sound). What are kirklands right now? Signia? If the kirkland software is the same as the signia software then there is a separate screen which reports the compression directly, though adjusting from there will effect the gain and vice versa.



Kirkland is technically Rexton. Uses Connexx, but a Rexton specific version. It has less fine tuning ability than Signia version, still allows compression adjustment (I think in fine tuning section)

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Before frequency compression I could not hear my security system beep when I turned it on. I could see the light and we have 30 seconds to get out. Well, sometimes we forget something and my wife can hear the beeping while in the garage (controller is inside the house) so she would tell me when it was safe to go back in, turn off the unit, and do whatever. With frequency compression I can now also hear the beeping through the door, while in the garage.



It’s the same software but you need the Rexfit module instead of the Sifit. Same version of Connexx though. Not locked.



I’m quibbling over “the same.” Last time I looked, the Signia version had more levels of fine tuning. For example something like noise reduction. The Rexton version might have 3-low medium and high whereas the Signia version might have 5 or 7 different levels. They are extremely similar however.



I found this chart below (not mine, from one of the hearing aid manufacturer’s papers) helpful to show how Wide Dynamic Range Compression is implemented. Like they say, a picture is worth a thousand words.

The level compression can vary at various frequencies, depending on the individual’s hearing loss at each frequency.