Soundhawk Review for Hearing Loss – Expert Analysis

Update: The product reviewed in this article is no longer available for purchase, and Soundhawk is no longer in business.

Manufactured by Foxconn (iPhone manufacturer in China), and created by an all star team (including ex Apple, Adobe, Cisco, Amazon, Motorola , HP, Jawbone staff), the Soundhawk Smart Listening System promised to be the the killer PSAP (Personal Sound Amplification Product). The Soundhawk sports a simple and elegant design, is bundled with a remote microphone system, and caters to the needs of both Android and iOS users. The Soundhawk was also the first PSAP to be successfully marketed as wearable device (in the ever-trendy hearables category). This gave the Soundhawk a huge, and unprecedented, boost in popular media coverage (for a PSAP).

PSAPs and Hearing Loss

Before getting to our in-depth Soundhawk review, I’d like to take a moment to reflect on the topic of PSAPs and hearing loss. PSAPs are not technically intended to help with hearing loss. Here’s a snippet from the FDA’s draft guidance on the topic:

PSAPs are intended to amplify environmental sound for non-hearing impaired consumers. They are intended to accentuate sounds in specific listening environments, rather than for everyday use in multiple listening situations. They are not intended to compensate for hearing impairment or to address listening situations that are typically associated with and indicative of hearing loss.

Let’s take the Soundhawk’s marketing:

We created Soundhawk to help people hear more of what matters most even in the noisiest places. It’s designed for those who struggle to hear soft sounds, converse over distance (such as talking to someone who is in another room) and understand speech in noisy environments.

While the FDA draft guidance is still only a draft, it certainly seems that Soundhawk’s marketing is in direct opposition to the guidance. Hearing soft sounds, hearing speech from a distance, and hearing speech in noisy environments are all situations where someone with hearing loss might struggle. However, I must admit, the FDAs guidance is extremely murky. Here is the list (of examples) of “intended” uses for PSAPs:

A PSAP may help with:

• hunting (listening for prey)
• bird watching
• listening to lectures with a distant speaker
• listening to soft sounds that would be difficult for normal hearing individuals to hear (e.g., distant conversations)

A PSAP may not help with:

• difficulty listening to another person nearby
• difficulty understanding conversations in crowded rooms
• difficulty understanding movie dialogue in a theater
• difficulty listening to lectures in an otherwise quiet room
• difficulty hearing the phone or doorbell ring
• difficulty listening situations in which environmental noise might interfere with speech intelligibility

This dichotomy seems extremely unnatural to me. Don’t people with normal hearing struggle to hear speech in crowded/noisy rooms too? It seems to me that the FDA is attempting to create two separate classes of hearing devices, where the only real difference is the marketing message. And there’s one huge problem with this approach: Even if PSAP manufacturers restrict their marketing message, the FDA can’t stop people from openly discussing their uses.

Customer Reviews for Soundhawk on Amazon:

Here’s a review snippet from user “kam” on December 2, 2014:

I have very bad hearing loss in my right ear and moderate hearing loss in the other…When I purchased my Soundhawk, it was with the hope that it would help my hearing in my right ear, but it did not. I called customer support in hopes I could turn it up (they were extremely helpful), but instead they suggested I use it in my left [good] ear. I tried it, and wow!

Here’s another from “Eric Stephan” on January 24, 2015:

I am a retired dentist. Hearing loss is very common amongst us…I was rather skeptical of this SoundHawk device but decided it was worth a try, particularly with the money back guarantee. I had nothing to lose. WOW!

Here’s “law prof” on January 23, 2015:

Soundhawk’s modest disclaimer about who its product is likely to benefit understates its power and value of the product for moderate hearing loss.

Lastly, “Peter T. Christy” on January 23, 2015

Soundhawk easily compensated for my hearing loss, but its additional features were an unexpected delight.

Let’s just accept the reality:

For better or for worse, people with hearing loss are using PSAPs to treat hearing loss. Let’s move on and talk about the potential of PSAPs for hearing loss, and then how the Soundhawk might actually work for someone with hearing loss. While we don’t officially endorse using PSAPs for hearing loss, we feel the audiology profession has a responsibility to help consumers make the right decisions.

Why I’m Excited about PSAPs

If you haven’t heard, there are a lot of people out there with hearing loss, many of whom need help:

Among adults aged 70 and older with hearing loss who could benefit from hearing aids, fewer than one in three (30 percent) has ever used them. Even fewer adults aged 20 to 69 (~16 percent) who could benefit from wearing hearing aids have ever used them. – More

Why do so many people neglect their hearing? There’s been a lot of speculation on this topic, and I won’t attempt to rank order the reasons.. but I can say that hearing loss denial, hearing aid stigma, and the cost of hearing aids have been significant factors in many studies. While PSAPs can’t help people overcome denial, they may help to overcome the stigma and cost barriers.

…over-the-counter [hearing] devices could reduce stigma, increase awareness of hearing healthcare, and improve [hearing device] adoption rates. – More

With the hearables market expected to grow to $5 billion by 2018, it’s clear that consumers are ready to embrace ear-level technology. For millions of people with a hearing problem, this revolution offers the chance to achieve better hearing anonymously and for a fraction of the cost. Inexpensive devices, like the Bragi Dash, could easily be shipped with an optional speech amplification/enhancement feature, and no one would ever know if you were using the device for heart rate monitoring, hands-free calling, or hearing improvement.

Why I’m Terrified

There’s a potential downside to the hearable revolution. Price conscious consumers may skip the audiological consultation all together, and jump straight to the solution (a PSAP, in our hypothetical world). While doing so may be harmless in many cases, some won’t be so lucky. Hearing loss may be caused by a number of underlying medical conditions. Some of these conditions are progressive, and without diagnosis and intervention, may lead to poor health or even death. I would recommend that anyone considering a PSAP solution first consult an audiologist to rule out any potentially harmful medical conditions.

Consulting an audiologist comes with other benefits. You’ll also learn how severe your hearing problem is, and whether a PSAP has the potential to help.

In-Depth Soundhawk Review

First let’s take a look at the specs. I won’t go into the specs published and readily available online, but rather the amplification, frequency response, distortion, etc specs.. the type of specs one might read on a hearing aid spec sheet – reference.

Soundhawk ANSI Specs

Frequency Range: <200-8000Hz
SSPL-90: Max 108dB @945Hz
HFA OSPL-90: 106dB
HFA Full on Gain: (Min/Max) 2dB/32dB

THD
500Hz <1%
800Hz <1%
1000Hz <1%

Equivalent input noise 31dB

For comparison’s sake, let’s have a look at the NP (Normal Power) version of one of this years most popular hearing aids.

Resound LiNX 61 Specs:

Frequency Range: <100-6930Hz

SSPL-90: Max 114dB
HFA OSPL-90: 109dB
HFA Full on Gain: 43dB

THD
500Hz <0.5%
800Hz <0.6%
1600Hz <0.8%

Equivalent input noise 24dB

When the Soundhawk is compared to a standard hearing aid, in terms of raw audio specs, we can see there isn’t a huge difference between the devices. The Soundhawk wins on having a slightly broader frequency range (more sound above 7kHz). The LiNX wins on heaving more amplification in the high tones (HFA Gain) and a lower internal noise level (equivalent input noise).

Note: These specs give a general idea of performance but are not directly comparable due to Soundhawk’s use of the 1989 version of the ANSI standard test).

So what do do these specs tell us? Does this mean you can expect the same performance from the Soundhawk as you could from the Resound LiNX aid? The quick answer is no. Specifications are measured in a controlled environment – In a test box where where sound from the hearing device’s speaker is not allowed to re-enter the device’s microphone port (a common cause of audible feedback which limits useful amplification). Furthermore, audio processing features are disabled during ANSI tests, to ensure all devices are tested on an equal footing. This means digital noise reduction, and other technologies, are not affecting the audio produced during the test. In other words, this is no way of evaluating the device’s function in the real world. To find out the realistic amplification characteristics, the Soundhawk needs to be tested in a test box and on the ear (via “real ear measurement” testing), without switching off audio processing features.

Test Box Measurements

We tested the following features in the test box to find out more about the Soundhawk:

1. Amplification performance
2. Directional microphone performance
3. Noise reduction performance
4. Wireless mic performance in quiet and in noise

We used the following setup for the Soundhawk, for all test box tests:

Our Test Box Setup

The Soundhawk “scoop” is seen in the center of the image (above). The scoop has a microphone and speaker. It’s job is to pick up the sound, process and amplify it, and send the resulting sound into your ear. The scoop is plugged into a sound measurement coupler (the shiny metal device) with some blu-tack (to ensure a good seal). The black speaker (in the rear of the photo) emits a speech sound which is picked up by the reference microphone (the black wire sitting just below the Soundhawk). The sound from the speaker also enters the microphone on the Soundhawk (which is on the bottom of the Soundhawk, right next to the reference microphone). The processed/amplified sound is sent from the Soundhawk into the coupler, where it is picked up by the coupler microphone and compared to the sound which is measured at the reference microphone. The difference between these sounds (coupler vs reference) shows us what effect the Soundhawk has had on the sound.

Note: The speech sound is controlled for level and spectrum by the reference microphone.

Speechmap Test

The first test we performed was the speechmap test. In this test we present the Soundhawk with some speech (at conversational level) from the Verifit speaker, and measure the performance of the device. On the graph below the green range illustrates the sound output envelope for the Soundhawk while the grey range shows the sound envelope with no amplification applied. We set the Soundhawk on the following settings for this test: On the “indoor” mode with the volume controller 3 steps from the top. For tuning we dropped the touch screen pin in the middle of the screen, between “full” and “bright,” and with half “boost.”

Note for audiologists: We used Speech-std(F) at 65dB

The results of the test show significant amplification from about 1000Hz through to above 8000Hz. There is roughly 20dB of amplification from 2000-6000Hz. A small amount of amplification may also be seen in the lower tones. What does this mean? Well, it means that, in an occluded (closed) environment, the Soundhawk is providing amplification successfully through a range of tones that are important for understanding speech, and that the Soundhawk should be effective as a speech boosting device for people with a certain type of hearing loss. However, there is one major limitation to these findings:

We are still only looking at how the Soundhawk performs in a test box.

At this stage, the Soundhawk is coupled tightly to the “coupler” and no sound is leaking out (i.e., an “occluded” or closed configuration). Only the sound coming out of the Soundhawk is being measured by the measurement microphone. Since the Soundhawk would typically be worn in a more “open” (less occluded) situation, where both 1) sound that naturally enters the ear and 2) amplified sound that comes from the Soundhawk would mix together – and where some of the amplified sound could “leak” out – this measurement may not be representative of actual use. In our next post, we will test the Soundhawk on an actual ear, rather than in a test box, where we can create the “open” environment more typical of actual use, and share that result with our readers.

For those who are curious, here are some more Verifit screenshots showing what the Soundhawk was able to do with the same settings for various input levels, and with max volume and max boost.

Directional Microphone Test

The next test we performed in the test box was the directional microphone test – designed into the Verifit 2 system. We were generally impressed with the directional microphones, but were surprised to find that the indoor setting outperformed the dining setting for directionality. As you may or may not know, directional microphones are designed to improve the signal-to-noise ratio of a person’s speech in a noisy room, etc, so we’d expect the greatest directional effect in the dining setting.

Based on the marketing literature, Soundhawk seems to agree:

Dining: De-emphasizes sounds from behind and beside you, helping you focus on people talking in front of you.

In the image above you can see a series of pink and green curves. The green curves represent the indoor setting, while the purple curves represent the dining setting. The difference between the two green curves shows the difference in sound level when the sound is coming from the front (thick curve) or coming from behind (thin curve). The same is true for the purple curves. Two things are clear when looking at the graph:

1. The directional microphone system appears to well through about 4000Hz, and provides some signal-to-noise improvement in the higher tones
2. The directional microphone system works better in the indoor setting than the dining setting

You may recall from our speechmapping test that the Soundhawk primarily amplifies sounds from 2000Hz and above. So it looks like there should be some signal-to-noise improvement in the part of the pitch range that is amplified. This is a good thing for bringing up some speech sounds over the background noise!

Noise Reduction

For the noise reduction test, we put the Soundhawk onto the “Driving” Sound Scene. According to Soundhawk’s publications, the driving scene “reduces road and wind noise” … What this means is that the Soundhawk is looking to reduce steady-state (or constant, non-fluctuating) sounds like the drone of the road on the highway, or a steady breeze. Our Verifit system was equipped with “air conditioner” and “vacuum” sounds, so we used those sounds to test Soundhawk’s noise reduction functionality.

Sound Samples – Wireless Mic

We recorded a couple sound samples of the Soundhawk using the wireless microphone. In the first sample, “Bar Noise Wireless Mic,” you can hear me speaking into the wireless microphone and recording the output from the scoop. There’s a little bit of rustling in the sound sample, and that’s just me holding the wireless mic in my hand (slight movements and touching my chest with the mic). The sound you hear in both samples is 100% Soundhawk – the scoop is completely closed off from the outside world in the test box, and our test box microphone can’t hear anything else (but the scoop output). We were careful not to clip the recording, and have attached an image of the collected waveform to illustrate this.

In the second sample, “No Background Noise Wireless Mic” you can hear the clarity of the Soundhawk’s wireless microphone system with no background noise present. We were curious to know how well the system worked in an ideal environment (one without noise). Click on the links below to listen to each clip:

Conclusion

So far, we’re generally impressed with the Soundhawk’s technology.

• Amplification is being provided 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

While we’ve taken some steps toward understanding the technology behind the Soundhawk, we still don’t know who the device is optimized for.

In our next round of tests, we’ll submit the Soundhawk to a series of “real ear” measurements, to find out just how much amplification is possible with the device in the real world. These tests will help us determine the ideal (and less than ideal) hearing loss candidates for the Soundhawk. We’ll be sure to provide more measurements and sound samples, to help our readers decipher our findings. Stay tuned!

Contributions to this article were made by David Smriga at Audioscan. The Audioscan Verifit 2 measurement device was supplied by Audioscan for the express purpose of assessing the Soundhawk.

Expert Review: Part II

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.

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

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).

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.

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.

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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.

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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.

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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.

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.

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

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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!

Letter from Soundhawk CTO

After posting the findings from our recent expert-analysis of the Soundhawk, we received a few extremely enlightening emails from the company’s Chief Scientific Officer, Drew Dundas, PhD. We asked Dr Dundas if we’d be able to post some of his responses here on Hearing Tracker. He agreed to share some of his thoughts publicly, and consolidated his thoughts into the following text. All questions and comments should be left in the comment section, at the bottom of this post.

Dear Dr. Bailey,

Thank you again for your in-depth and insightful review of the Soundhawk Smart Listening System. As you noted in your comprehensive review, Soundhawk was founded to bring enhanced listening performance and increased ease of listening to a wider range of individuals. Our team is unique in the hearing space, bringing together hearing experts with innovators from the consumer electronics world. Our founder, Dr. Rodney Perkins, is the founder of ReSound, a well-known otologist and professor of surgery at Stanford University who has been a champion for improved hearing health throughout his extensive career.

During my time as a Director of Audiology at UCSF Medical Center and as a clinician at Vanderbilt University Medical Center I was frequently struck by the obvious need for a high quality, high technology product that is intended for use by individuals with situational listening difficulty.

What is situational listening difficulty?

Many of your readers have probably heard or even described for themselves the experience where the listener doesn’t have any difficulty following a conversation with a friend in their own living room, but if that conversation were to move to a noisy restaurant, it becomes a whole new ball game. In fact, a study published in late 2014 by the Consumer Electronics Association reported that as many as 98 million adults in the United States report difficulty listening and understanding in common situations. That’s almost half of the adults in the US.

For a number of reasons, the majority of these individuals aren’t candidates for care through the traditional Audiology channel, including the fact that many of these individuals likely have hearing sensitivity (i.e., audiometric test results) well within the normal range. For these individuals, improving the audibility of the speech signal (what we tend to think of as ‘making things louder’) is of secondary importance to improving the signal to noise ratio. The term signal to noise ratio, of course, refers to the relative presence of the things that you want to hear (the signal) versus the presence of the things that you’d like to ignore (the noise). Soundhawk is the first and only consumer product that is intended to enhance listening performance and ease by focusing on personalization of sound and enhancement of the signal to noise ratio.

In your review of the Soundhawk Smart Listening System, it is astutely observed that Soundhawk enhances key speech frequencies via careful manipulation of the sound signal. Unlike hearing aids, which are intended to compensate for a loss of hearing, Soundhawk’s processing is intended to enhance the hearing performance that exists. There are no compromises for the user. Our personalization system allows the user to simultaneously manipulate more than 150 different parameters with a simple drag of their finger through our patented personalization app on a smartphone or tablet. These changes are much more complex than a bass/treble and volume control. Because listening conditions change, the Soundhawk user can readjust their settings as often as they’d like, simply by returning to the Soundhawk App.

During the test box evaluation of Soundhawk, the reviewers observed a more robust directional response in the indoor mode than in the dining mode and question the reasoning behind this performance. It would appear that these results are an artifact of the test protocol, rather than a flaw in the implementation of the directionality system. In the Indoor sound scene, Soundhawk utilizes a fully automatic adaptive directional microphone mode. That is, when there is very little background noise, the microphone response pattern is omnidirectional, lowering the system noise floor and improving sound quality. When background noise is detected, the system goes into a ‘search and destroy’ mode, reassessing the signal to noise ratio hundreds of times each second and adapting the microphone response pattern to maximize the SNR in front of the user.

We selected an automatic adaptive strategy for this mode because we know that most competing noise at home is stationary, such as what might be produced by home ventilation, an adjacent kitchen or traffic noise through an open window. In addition, many users prefer a baseline setting that is highly versatile and effective. The Audioscan Verifit directional test utilizes a test stimulus containing speech or noise that is presented from speakers in front of and at 90 degrees to the microphone array. Because the Verifit noise source is at 90 degrees from the signal, the automatic adaptive directional mode of the indoor setting is able to adopt a response pattern that is less sensitive to sound emanating from this direction. In the dining mode, on the other hand, we force the system into a fixed directional response pattern that is more sensitive to sounds coming from the front and just to the sides, the presumed location of dining companions and conversational partners. We chose this setting because of the highly variable acoustic environment of a restaurant. A quickly adapting response would result in major fluctuations of the level of sound, an effect that is distracting to many listeners.

It was gratifying to see that the noise reduction system of the Smart Listening System worked well in the test box in driving mode. Use of the vacuum cleaner and air conditioner sound effects was creative, but may have underestimated the efficacy of the system for road noise and wind, sounds that are more typically encountered when driving than is vacuum cleaner noise.

The assessment of the wireless microphone performance was impressive. The reviewer’s recordings did an excellent job of illustrating the effect of the system on ease of listening in background noise. As audiologists have advocated for decades, wireless microphones massively enhance the signal to noise ratio for all listeners, making understanding in noise much easier and less tiring. Until Soundhawk, however, this wireless technology has not been available at a price point that is easily accessible for most people.

Soundhawk is unilateral in design because individuals with situational listening difficulty can derive greater benefit in noise from signal to noise ratio improvement than from amplification. A unilateral design is simple, versatile (it doubles as an excellent Bluetooth headset for use with your smartphone!), effective and affordable. While the ‘perfect’ fit might not be achieved by a user without the assistance of a professional, one really has to ask what ‘perfect’ means. The audiogram based fitting targets described by the reviewer are averages based on one aspect of hearing only: the softest sounds detectable by the listener. While this approach has been well validated to provide benefit in terms of enhanced audibility for speech, it is more difficult to say that they predict user satisfaction. In fact, the literature suggests that while these targets serve as an excellent starting place, they should not be considered the ‘final destination’. The scientists who developed the NAL-NL1 fitting target algorithm also published a paper that pointed out the fact that different listeners might prefer settings that varied from the audiogram-based prescription by as much as 20dB, reaffirming that the fitting target should be considered no more than a starting place for a satisfied user.

The reviewers note that when the Soundhawk system is operated at maximum volume and maximum boost in a noisy situation, that sound quality may degrade somewhat. This does not occur because of a hardware limitation, but rather due to our careful setting of the maximum output parameters of the system. We consider it our responsibility to ensure that it is never possible to produce an output level that would be hazardous to the hearing of the user. Accordingly, we carefully tailor the gain, compression ratios and output limiter settings such that output is maintained in the safe range. If the user encounters distortion or other degradations in sound quality when listening in noisy situations, it is recommended that the volume control level be decreased until sound quality improves.

Lastly, the reviewers question ‘who is Soundhawk for?’

Soundhawk has developed a simple test to determine who might benefit from the use of the Smart Listening System. In essence, If you experience little to no difficulty listening to conversation in a quiet room, but struggle in background noise, or when listening to the television with others, Soundhawk will likely help you to listen with less difficulty and less effort. If, on the other hand, you experience difficulty listening and understanding in quiet, you would likely perceive greater benefit from professional evaluation and treatment.

We at Soundhawk appreciate the interest, thought and obvious expertise that went into the Hearing Tracker review of the Smart Listening System. As always, we recommend that everyone should have their hearing evaluated by an audiologist or hearing healthcare professional, and carefully compare the features and benefits of the various approaches to improving situational listening performance before making a decision on how to go about improving their ease of listening and quality of life. Potential users with medical symptoms including sudden changes in hearing, tinnitus, dizziness, ear pain or drainage should consult their healthcare provider prior to using Soundhawk or any other hearing related products.

Sincerely,

Drew Dundas, PhD, FAAA

Chief Scientific Officer

Soundhawk Corp