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Last month we posted our analysis of the Soundhawk’s performance in a hearing aid test box. If you didn’t have a chance to read the review (and don’t have time now), here’s the bullet-point summary of the results:

  • The Soundhawk provides amplification successfully through a range of pitches important for understanding speech
  • The directional microphone system provides some signal-to-noise enhancement in the pitches that matter – works best in the “Indoor” setting
  • We are seeing 5-7dB of noise reduction for steady state noises between 50-70dB
  • The wireless mic system works well in quiet and in noise

As we explained before (see the “Speechmap Test” section of our previous Soundhawk review post), the hearing aid test box is not the best way to determine real-world performance for hearing devices. To assess the real-world functionality of the Soundhawk, we needed to measure the device’s performance in a real ear. We used a well-established technique, known as “real-ear measurement,” to gather the results. For those who aren’t familiar with real-ear measurements, we’ve created a (rather crude) graphic to help illustrate the concept.

ear

As you can see in the image, a microphone is placed deep within the ear canal, beyond the Soundhawk. After the microphone and Soundhawk are in place, sound (in our case female speech) is played out in front of the listener. The sound is picked up by the Soundhawk, processed and amplified, and sent into the listener’s ear. At this point the amplified sound is picked up and recorded by the ear canal microphone for analysis.

Here’s the simplified bullet-point version of our real-ear measurement procedure:

  • The listener is positioned in front of a speaker (see photo below)
  • A canal microphone is positioned deep within the listener’s ear
  • The Soundhawk is placed into the same ear as the microphone and turned on
  • Sound from the speaker is picked up and amplified by the Soundhawk
  • The sound coming from the Soundhawk is picked up by the ear canal microphone
  • Measured sound is analyzed

Real ear measurements in action

real-ear

Image Courtesy Audioscan

Give and Take

In our first test, we wanted to find out how much amplification the Soundhawk provides on it’s default setting. When we first started up our Soundhawk, and went to the initial tuning for the “Indoor” mode, we were presented with the following settings (see phone screenshot on right).

Screenshot_2015-02-15-21-58-19

Effectiveness of the Soundhawk ON vs OFF

In our first set of measurements we looked at the sound coming into the ear with and without the Soundhawk in place, and then with the Soundhawk in place and turned on.

Speechmap1

There are a couple things worth mentioning here. First, the Soundhawk has very little effect on sound entering the ear when inserted and turned off. In other words, the Soundhawk is not blocking outside sound like an earplug would. The difference between the teal and green lines shows the minimal sound-blocking effect of the Soundhawk. These results effectively classify the Soundhawk as an “open fitting” amplification device. Lastly, the Soundhawk is providing significant amplification on its default settings (the purple line). More on this to come.

  • The Soundhawk doesn’t close up the ear acoustically when put in place. In other words, it doesn’t act as an earplug.
  • The Soundhawk does block some external sound (at around 2000-5000Hz) slightly
  • The Soundhawk produces significant amplification when turned on (at 1000-8000Hz)

Sound Boost on Default Settings

This image shows a clear view of Soundhawk’s amplification effect on default settings. We can see a significant boost in the speech envelope when comparing the grey area (normal speech) to the green area (amplified speech). Amplification is effectively seen between 1000-8000Hz.

Speechmap2

Amplification for pitches in this region should be helpful as this pitch range is vitally important to understanding speech. Considering the results of our directional microphone testing (see last post), most everyone – including normal hearing listeners – should experience a hearing enhancement while using the Soundhawk in noisy situations. The exception: If the Soundhawk isn’t loud enough to cope with your hearing loss, you won’t see the desired results.

How Bad Can My Hearing Loss Be?

Our next set of results attempt to answer this question. If you are considering buying a Soundhawk to “treat” your hearing problem (or you’re a provider considering fitting one on a patient), please consult this section carefully!

In our first test, we found the ideal hearing loss for the Soundhawk, using the default settings for the device on “Indoor” mode (see phone screenshot above). As it turns out the Soundhawk does a great job of amplifying sound for a slight-to-mild hearing loss centered around 3kHz/4kHz.

Threshold_entry1

Above: The hearing test result that is “ideal” for the Soundhawk (on default settings). The test shows a slight/mild hearing loss at some of the higher pitches.

Speechmap_NAL_NL11

The image above shows a green line intersecting a series of green markers. The green markers are prescriptive thresholds generated based on the hearing loss levels shown (using NAL-NL1). The green line represents the amplification of sound produced by the Soundhawk across a range of pitches. The goal (in this test) is to have the amplification (green line) match up with the recommended prescriptive targets (green markers). Since the Soundhawk is capable of meeting the amplification targets, we know that it’s capable of bringing benefit to someone with the hearing loss levels depicted.

Note: If you suffer this level of hearing loss in both ears, it may be worth considering a solution that provides balanced amplification to both ears, or risk losing out on the advantages of binaural hearing (alternate).

No Really. What’s the WORST I Could Be?

You might have noticed that the test results above were for Soundhawk’s default settings. As you know, the Soundhawk comes with a smartphone app that enables bass/treble alteration, as well as volume control. We went ahead and pushed Soundhawk as hard as it could go, and turned the volume to max, and the boost to max. To recreate our settings, see the screenshot on the right.

Screenshot_2015-02-16-20-40-22

We entered the following hearing test result into our amplification-prescription machine. The hearing loss is described as mild-to-moderate, worst at around 3000-4000Hz.

Threshold_entry2

The image below shows the Soundhawk matching the prescription for the mild-to-moderate hearing loss entered (above).

Speechmap_NAL_NL12

There are some important things to note about this second test. First, when we turned the Soundhawk up to maximum gain/boost, we found it was much more likely to sound distorted when listening to recorded speech passages. An analogy might be turning your phone volume up to max. At some point you reach the limits of the speaker hardware, etc, and start hearing a lower quality sound. This was our experience with the Soundhawk at maximum volume.

The second thing worth noting is that the Soundhawk was much more likely to give off an audible whistle (acoustic feedback), especially when in proximity to a nearby object. For example, when we waved our hand near the ear of the subject wearing the Soundhawk, we were greeting by a brief, but loud, screeching sound. We did experience some feedback at lower volume levels, but it was harder to trigger, and softer by comparison.

Should I Buy a Soundhawk to Treat My Hearing Problem?

We’ve explored the range of hearing losses that are potentially covered by the Soundhawk. We’ve determined that Soundhawk is ideal for slight/mild hearing loss, and capable of providing adequate amplification (with some side effects) up to a moderate level hearing loss. While not officially intended to treat hearing loss, it’s clear that Soundhawk is capable of operating as an efficient low-powered hearing aid for consumers with lower levels of hearing impairment.

Our conscientious list of caveats:

  • If you have hearing loss in both ears, you should consider a solution that provides amplification to both ears.
  • If you have hearing loss in only one ear, you should definitely get checked out by a hearing health provider prior to taking your next step.
  • If you fit the Soundhawk on yourself, you may not achieve a perfect fit to your prescription. Consider getting help from a provider to maximize benefit!
  • Hearing Tracker does not endorse using Personal Sound Amplification Products to treat hearing loss!

UPDATE: Soundhawk has officially responded to our review.

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