Are extra Features worth the money?

If you read the manufacturer’s literature or read some of the forum comments by people who earn their living selling hearing aids, you are told that more is better. Is it really true that all these features, like echo block, adaptive directional microphones, wind noise reducers, etc. really translate into better speech comprehension?

Is there scientifically derived proof that these gadgets help? Or do they actually reduce comprehension?

For example, every one says that adaptive directional mikes are a must in noisy situations. Are they better than the lower cost fixed directional mikes?

See http://www.hearingreview.com/issues/articles/2007-09_04.asp

This author reviews several actual tests of adaptive mikes and found they were no better than simple directional mikes.

Ed

My personal experience is that most clients reports better speech
understanding with adaptative directionality vis a vis fix ones.

I think that the key is to dispense the client the aid with the features which provide the best benefit. Example, I had a client which played golf. The wind noise feature was a main thing to him and the reason why he upgrade his aid.
To him this was important, and we was willing to invest in this…


VAPORIZERS INFO

xbulder: Of course if the client needs the feature and it works without degrading comprehension or overloading the DSP or draining the battery, then by all means it should be included.

I have not seen any technical papers on the performance of wind noise reducers. Obviously it must work by reduction of the wind noise frequencies. If this doesn’t mess up anything in the speech area…wonderful.

I am not saying that features are all bad…but if they substantially raise the cost of the aid or degrade overall speech comprehension for any reason then they may be of questionable cost-benefit in the real world. Fortunately most of the newer Digital Sound Processor (DSP) chips are fully programmable. So the manufacturers can load whatever they have in firmware.

Interestingly, I am told that the difference between the top tier of aids and the medium priced aids from many mfg’s is all in the burned in programming of the DSP. The physical aid is identical.

Reminds me of the difference in dishwashers. The top tier have some chrome here and there and a few minor features and cost a lot more (and offers the merchant more profit). Ed

this is true and i have raise that point. let me remind you that sometimes the
software is more expensive than the PC itself. Most of the top end instrument
uses propietary formula that takes a lot of money to develop, there are companies who invest a great deal of their sales to develop this fitting rules, hence the cost diferential.

However, in time those formulas become available to other mid and low end products…

For those who went to business school this is call unbundling. from the supply chain point of view; it is a must a dollar save in supply chain goes directly into the botom line. This has been the standart in the industry for quite some time… this is no secret.


Cb650Sc

One of the reasons the much praised two microphone directional feature may not work as well as the simple single mic., has to do with the signal to internally generated noise ratio. (Note this is internally generated noise not external noise).

When you combine the signal from two closely spaced mikes the output is much much lower than from a single mike. This allows the internal noise to climb to much higher levels. To compensate many mfg’s use squelch or a low level knee. This has the disadvantage of eliminating speech cues from the very low level information.

So in some cases a cheaper single mike works better than a more expensive dual system. Though in a typical restaurant if the bulk of the external noise is coming from directions other than directly ahead the dual mikes probably will give somewhat better signal to external noise ratio and could possibly improve comprehension.

Personally, I try both programs in a noisy restaurant… Ed

I believe what most manufactures use call expantion (opposite of compression) sort or like a reduce gain below the thresold knee …


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