Speech banana

Hearing Loss
#1

Hello,

One theoretical question:
When we look at banana speech region and all the speech sounds within, what are our assumptions with regards to volume and distance from sound source:

  • coversational speech level of approx 60 db
  • distance from sound source - 3 feet?
    is this correct?

What would happen with this sounds from banana speech region if we would come closer to the one who is talking - with distance being only 1 feet . How much would the sounds (f ex. high pithed sounds) be amplified and would they go out of that banana-shaped region in doing so?

I hope I made my self clear and thanks in advance!

#2

The exact origins of the speech banana are a little obscure. Here’s an Internet discussion started by someone doing a review article: https://www.researchgate.net/post/What_is_the_origin_of_the_speech_banana#

For speech, the speech banana implicitly includes the loudness of the sound as you would hear it that is typically made at the distance that you might normally hear it but the loudness, I would think, is the volume impinging on your eardrums. I think the speech banana started just on the loudness required to hear consonants and vowels at a normal conversational distance - a few feet. I would presume other sounds, like birds singing, crickets chirping, are derived from just some average measurement of sound volume of those noises from someone out in the world with a sound meter. At the origin of the sound, whatever it is, obviously, might be much louder. But again, it’s someone’s guess as to the average volume hitting your eardrums. If you could get a bird or a cricket to chirp directly into your ear, that might be able to compensate for quite a bit of hearing loss.

There are lots of speech banana references on this forum. But here’s another speech banana reference from Wikipedia with the required creator reference:

image
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By DiegoSLP, CC BY-SA 4.0, File:Speech Banana no icons.png - Wikimedia Commons

#3

The answer to your question lies in the subject of LTASS (long term average speech spectrum). It’s a good question, especially since there isn’t even a single accepted definition of the speech banana. This is from page 213 of “Fitting and Dispensing Hearing Aids, Third Edition” by Taylor and Mueller:

IMG_8615
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2 Likes
#4

Hi Jim,
Thank you for your response.
I forgot to give some example from real life:
At my workplace, quite office without background noise, there is a business meeting and my colleague speaks typically soft (quite) and has a bit of high-pitched voice. Our distance is around 3 feet. Without hearing aids I am having difficulty understanding him, as his speech sounds more like mumbling and there are lot of gaps to be filled because of my high-frequency hearing loss.
So, basically, now we come to the main question:
What would happen if I would come closer (distance between 12-18 inches, entering his intimate zone so to speak) to my colleague who is speaking, would his speech become more clear to me? Would this high-pitched sound become more audible and intelligible? Basically would they move out of this banana-shaped region from speech banana chart?

#5

Moving closer would increase the volume of the sound, much like lower end hearing aids. That help some people.

#6

And would give the guy an incentive to speak up! :smile:

3 Likes
#7

Your posts don’t say what model HA you’re wearing. As an alternative to moving closer, if you wear Phonak Paradise or Lumity hearing aids, you might want to check with your HCP whether the Speech Enhancer function is turned on. In quiet listening environments, the Speech Enhancer function can enhance soft speech by up to 10 dB, a tremendous boost in SNR. But it only works if your fit is set as an Experienced or Long-Time User. And your HCP can adjust the amount of speech volume amplification. Presumably, it’s not going to work so well (or at all?) in noisy environments, probably because it won’t be able to pick out soft speech from the noise.

I trialed the Lumitys and was really impressed by that feature. My wife is very soft-spoken, and I think, even with my HA’s in, tends to roll her sounds (she’s not a native English speaker). I could hear her very clearly, even at some distance, with the Lumitys. I thought when I switched to trialing the Omnias with M&RIE receivers that I’d be disappointed relative to the Lumitys on the ability to hear my wife’s soft voice. I was greatly surprised and think that it must be because of the mics on the M&RIE receivers in my ears. Possibly, I can take full advantage of the natural pinna effect in amplifying speech frequencies and ignoring others. Thus, I elected to go with the Omnia because it was available with a disposable battery whereas the Lumity currently is offering only with rechargeable and just enough runtime to get through the day if you use its full charge range, which may deteriorate with age, being a rechargeable (consumable) Li-ion battery.

Here’s a Scientific American review on the pinna effect. I expect to get my purchased Omnias with M&RIE receivers in custom molds later this week and will add any significant observations (and maybe some insignificant ones, too!) to the following thread: ReSound Omnias with M&RIE Receivers

Ears: Do Their Design, Size and Shape Matter? - Scientific American

The Sci. Am. article says that the pinna effect can amplify speech frequencies effectively up to 100x, ignoring sound frequencies to either side of that range. RIC and BTE HA’s try to simulate an artificial pinna effect, which may not work well for everyone, while ITC and ITE devices can take advantage of the natural pinna effect (but often have less functionality and battery runtimes because of the size constraints of their placement).

P.S. I doubt one normally gets as much speech enhancement out of M&RIE receivers as the Scientific American article claims for a normal pinna effect. If one did, ReSound would be trumpeting it to the skies. The main thing ReSound claims for the M&RIE receivers is modestly improved sound localization and perhaps a more natural sound, IIRC.