Philips Hearlink receiver power options - possible peaking-distortion

Hearing Aids
#1

I am a few weeks into trial of 9040s (coming from KS10/Phonak). Current receivers in Philips are 85 power, and am wondering whether 100 power might be better match to me and audiogram? My speech comprehension is still so-so, and especially in treble of voice it seems that the sound is smearing and not ending completely and cleanly. Even with the startup “pure tone” sequence some of the tones seem slightly smeared/distorted (like a hifi speaker peaking).

In dealing with this Costco they are fairly cost conscious about equipment and seem to only swap receivers if there is good reason, so I seek experienced forum comments, thanks. Like with KS10 I expect I will do DIY once HCP gets HAs more in the ball park.

{I had also done a short - mostly unsatisfactory via audi of Oticon Real and above distortion was much worse, but greatly improved when audi exchanged 85 power for 100 power. While Philips 9040 hass some similarity to Real they are different so my Oticon experience is only suggestive.}

image
image978×753 90 KB

2 Likes
#2

I think the 85 dB receivers should work fine with your hearing loss, but I don’t see much wrong with upsizing to the 100 dB receivers if you want to have some margin for future proofing in case your hearing loss gets worse than what the 85 dB receivers can handle later on.

I’ve heard some argument that using an oversize receiver may increase the harmonic distortion, but honestly I’ve reviewed the harmonic distortion specs for these receiver sizes and it’s so low that even if there’s a slight increase, it’d be minimally unnoticeable by you. But last I checked, they have the same percentage of harmonic distortion rating.

Also, I think if you drive the 85 dB receivers very hard near its edge of performance, my personal opinion is that they’ll probably be failing sooner rather than later. But with 100 dB receivers for your 85 dB loss, there’s some room there for margin so that the 100 dB receivers don’t have to be worked right up to their edge of performance all the times. This may help make them last a little bit longer.

The obvious drawback I can see is that if you have small ear canals, it may be harder to fit the bigger 100 dB receivers into smaller ear canals than the 85 dB ones. And even if it still fits, it may feel a little less comfortable if there’s not much room left for the dome to seal up your ear canal and the whole fitting may be too snug, more than necessary.

2 Likes
#3

@Volusiano Excellent info and points as usual, thanks. I have custom molds so swapping to 100 power might not be quite so easy. In my Oticon Real trial it was with domes so not an issue. Perhaps I will suggest to HCP for me to trial 100 power with appropriate domes, and if what I am labeling as distortion (and my guess is THD rather than HD) improves then remake molds or have modified to accommodate larger 100 size. Do 100 power also have different wax guard? Also I realize I am assuming - perhaps incorrectly - that by “bigger” size you refer to diameter but it might only be in length. My ear canals are of moderate size without unusual features/bends.

#4

Below is the fitting chart for Oticon. I know we’re talking about Philips aids here, but I’m an Oticon wearer, so I only have Oticon data. But I think it’d be safe to assume that the fitment is the same for Philips as it is for Oticon because they’re all from the Demant William umbrella.

You can see that the 100 receivers can be fitted with bass dome double vents or the power dome, so you should be able to try the 100 without paying for a custom mold.

Below is also a picture of the 100, 85 and 60 receivers. It looks like they use the same wax guard. As for the size, it seems bigger in both diameter and length. So the fitment may or may not be an issue depending on how your ear canals are.

image
image1291×867 111 KB

image

2 Likes
#5

@Volusiano Excellent info and points as usual, Thanks!
When streaming music or watching Youtube, my wife was able to hear the sound leaking from the HAs - sitting 3 feet away from me. Having More 1 with 100dB receiver on power dome.
During the last Audi’s visit, she mentioned that 105dB receiver is not much different/improvement from the100dB receiver for my HL as shown on Genie. So no point of getting the 105dB mic in power receiver mold. Not many HCP has stock of 105 dB receiver. To get the 105dB in power receiver mold is difficult. Even in Ebay, very few seller offering 105dB receiver. I just stay with More 1 + 100dB + power dome as a spare HA’s.
Since I have an preowned Xceed 1 UP with normal tube and ear tips, the sound was louder and able to hear in noisy restaurant. I was able to hear my voice when talking to my friend who was sitting infront of 4 foot cooling fan. My friend was not able to hear what I was speaking in front of him. I was able to hear my friend speaking. I will be getting a mold with the length to the 2nd bend in a few weeks time for the Xceed. Hope it helps for my HL.