Why frequency range limited to 6K?

A normal person can hear from 20Hz to 20000Hz, but almost all hearing aid cut its frequency to about 6KHz. Why designer of HA do not extend the freq. up to 12K,15K? since high freq. sound helps speech discrimination.

Just not necessary? or HA industry habit? or limitation of IC, receiver?

Anyone has comments?

most modern HI goes up to 10,000 - I have seen Widex, Oticon, Siemens and rexton with extendend frequency responses.

Most audiometers only measure 8,000. Others you need special headsets to
test 16,000hz

A normal person can hear from 20Hz to 20000Hz, but almost all hearing aid cut its frequency to about 6KHz

Err … but hearing aids users do NOT have normal hearing.

Many cannot hear anything above around 7KHz.

Also very little speech data is above 5k or 6k.

Have a think: millions of hearing aids are fitted each year and many are very new & high tech … but STILL only boost up to around 10KHz max.

If an extended frequency response above around 8k was important, why don’t we see it in hearing aids? Because it is NOT too important!

ex. freq. response above 8K is important for localization and speech cues…
Most HI will have that eventually

Probably … but that won’t benefit more than a minority.

Most of my clients are close to running out of steam at 8KHz.

For example, I have 20-30 dB hearing to 6KHz and so don’t need a hearing aid. At 8 KHz … ho hummm … nobody home. Does that give me problems? Well I can’t hear bats any more.

A flat response from 20-20KHz would be perfect hearing; not normal hearing. Most CRTs have some emissions at ~15KHz, yet you will find few people can hear them.

Zafdor is right. And in addition, research shows that only a few people will benefit from having much amplification above that. There are some people who do. For most people the deterioration is gradual from about early teens, so that we become unaccostomed gradually to using the information

This is wrong. Frequencies over 10kHz are said to make sound more natural and alive.

Widex hearing aids reach 11.2 kHz, I think.

There are physical reasons for why hearing aid receivers are poor at amplifing over 10kHz. Also, sampling rate needs to be limited because of power limitation.

Apart from that, it is more important to spend the bits on increased dynamic range than increased sampling frequency so hearing aid users can enjoy live music.

And useful hearing range might be viewed in octaves:.

So, the perfect normal Human Sound octaves are approximately 20hz to 40…40 to 80…80 to 160…160 to 320…320 to 640…640 to 1280…1280 t0 2560…2560 to 5120…5120 to 10240…10240 to 20480hz. 10 octaves in all. (Anything below 20hz or so is felt not heard.)

Now if the upper octave is missing, one way to look at it’s loss is to say one tenth of the range is unavailable. And looking at the thing from a power viewpoint most voice power is concentrated well below 5 khz.

I’m not aware of any high grade scientific papers showing that speech comprehension is improved with the most upper octave…maybe out there but as I said, I never ran across them. Ed

This is wrong. Frequencies over 10kHz are said to make sound more natural and alive.

Only if you can hear them … which 98%+ of my clients can’t.

I too am bothered by the fact that upper octave, 10K-20K audio range is not address by HA manufacturer, because as new user of a HA, I know what “normal hearing” is having been able to hear the 15K sound of a TV set and above even into my 40’s. Do any HA’s provide extended response ranges to provide for a “normal” hearing range (not perfect)? Thanks.

Here’s a good frequency chart.

http://www.independentrecording.net/irn/resources/freqchart/main_display.htm

Don

I am new to this forum. Googled “hearing aid frequency response” and got here.

Since 4 weeks I am testing hearing aids. My hearing problem gradually developped and I have perfect hearing till 2 khz. A dip at 4khz of 50 dB and then it returns to about 40 dB at 8 khz.
I am (was) a sound engineer and extremely focussed on tonal balance and “how things sounded in the past”. I am convinced the hearing aids could be better in freq. response. I think speech clarity and understanding would greatly benefit also from everything between 6 khz and lets say 15 khz.

I am using a Widex 220 RITE device and it disappoints in amplifying HF. I see no reason why it is limited. I also do not see the answer here. Dubbling the sample freq. should not be a problem for instance. Just change batteries more. I am going to ask Widex. It’s a mysterie to me.

Still another way to view the missing top frequencies is to view the amout of usefull speech information up there versus the amount of noise in the upper octaves.

There is so much useless noise in the upper ranges that it can mask useful info lower down.

Also extending the range has other penalties such as requiring different parameters in the A/D-D/A that eat batteries. Ed