Audiologist's Review of the Soundwave Sontro OTC Hearing Aid

It’s official, OTC hearing aids are finally here! One of the first options to hit the market are the Sontro hearing aids They are produced by a company called Soundwave, which is based out of Oak Brook, Illinois. Prior to the release of the Over-the-Counter Hearing Aid Act, the Sontro devices were available as a direct-to-consumer product, which means that Soundwave has already had the chance to evolve this device over time. Now that the Sontro is available as an over-the-counter (OTC) hearing aid, Soundwave has made improvements to make them even more cutting edge.

In the Box

The Soundwave Sontro is a small, receiver-in-canal style hearing aid that is self-programmable through their otoTune app. They are available to purchase online for just $999 a pair in either beige or gray, and are only available for purchase as a pair. Soundwave offers a 45 day return period, so if you decide these particular devices are not for you, you can return them for a full refund inside of this window. If you do decide to keep them, the Sontro OTC devices have a one year warranty from the date of purchase. The hearing aids themselves feature dual microphones to allow for directionality, as well as a push button control to adjust the volume. They are powered by size 312 disposable batteries. Right now Soundwave does not offer a rechargeable option.

When you first receive the Sontro OTC hearing aids, they come with a size 1 receiver already attached. Soundwave also includes a measuring tool in case you need a different wire length, which they will send to you for free. They also come with several different dome options so you can find both the right size and dome style to suit your hearing loss. You can purchase additional receiver wires, wax traps, and domes directly from Soundwave.

In terms of overall build quality, the Sontro OTC devices fall around the middle of the road for hearing aids, which can be expected at their $999 price point. While they do have a comfortable fit, they are a bit bulkier than other size 312 battery hearing aids. Once you close the battery doors, they play a startup jingle, then verbally tell you the program in which you are starting. The Sontro OTC hearing aids connect via Bluetooth to Soundwave’s otoTune app, which is where you will be able to take an in situ hearing test and make adjustments to your hearing aid programming. Unfortunately, the Sontro OTC hearing aids do not support Bluetooth streaming.

In Situ Hearing Test

It is definitely a good idea to take the in situ hearing test through the otoTune app, even though it is not required to use the devices. The test only takes a few minutes to complete, then the otoTune app will program your hearing aids to first fit settings based on your results. To make sure you get accurate results, the app will verify that your environmental sound level is quiet enough. You will hear pure tone beeps through the hearing aids, then simply click whether you heard a beep in your right ear or your left ear. There is an audible clicking sound as the beeps are presented, so even if you do not hear the pure sound you may hear the clicking as the tone is played. This is a major flaw that will hopefully be fixed by Soundwave in the future, but for now try to ignore the clicking and only respond if you actually hear the beep after the click.

After the test, otoTune will load the first fit settings into your Sontro hearing aids and you will be able to review your test results. If there are any asymmetries between your ears, the app will give you a warning and recommend that you follow up with an audiologist or physician. If you do not feel the results are accurate or if you feel your hearing has changed, the otoTune app does allow you to retake the test at any time.

otoTune User Controls

After you view your test results, you can go into the app to make further adjustments. The hearing aids will default to an automatic program, which will switch between programs depending on the acoustic environment you are in. You can also manually switch between the programs, which include Quiet, Noise, and Entertainment. The app allows you to adjust both hearing aids together or to adjust one at a time. Within each program, you can increase or decrease the overall volume levels, make adjustments to bass, mid, and treble levels using a three band equalizer, as well as adjust noise reduction and feedback cancellation.

The environmental triggers for the Quiet and Noise programs are pretty self explanatory, and the Entertainment program will activate if the hearing aids identify music in your environment. Of course, the only way to verify if your Sontro OTC hearing aids are amplifying sound appropriately for your hearing loss prescription is if their output is verified by an audiologist using real ear measurements. This is the only way to ensure you receive the maximum benefit from your over-the-counter hearing aids. 

Real Ear: How Did they Measure Up?

We measured the output of the Sontro OTC hearing aids to see how closely we could adjust them to meet my NAL-NL2 prescriptive targets, since I have a mild to moderate hearing loss.

It must be noted that Soundwave uses a FIG-6 prescription, so we did not expect the Sontro hearing aids to meet an NAL-NL2 prescription right off the bat. After taking the in situ hearing test through the otoTune smartphone app, we used real ear measurement to measure the first fit settings of the Sontro OTC hearing aids. They met my prescriptive targets pretty well in the low frequencies up to 750 Hz, but significantly underamplified the high frequencies. The high frequencies are what provide clarity, so if you do not make any adjustments to your Sontro OTC hearing aids beyond their initial settings you will likely still struggle with understanding speech.

In the Quiet, Noise, and Entertainment programs, the initial settings were identical. The main difference between the programs appeared to be the directionality. The Noise program provided significantly more amplification to sounds coming from the front than it did to sounds coming from behind, which is good in a noisy environment so you can better hear the person in front of you over the noise around you. The Quiet and Entertainment programs both used an omnidirectional microphone configuration, because there was no difference in the amplification level regardless of the direction the sound was coming from.

After a considerable amount of adjustments using the three-band equalizer, we were able to match my NAL-NL2 prescriptive targets out to around 3000 Hz, which is not bad for a $999 hearing aid with 3 adjustment bands. The Sontro OTC hearing aids were not able to meet my targets as closely as a prescriptive level hearing aid, which generally has about 24 frequency adjustment bands. The Sontro OTC hearing aids also significantly underamplified soft level speech even after they had been programmed to my prescription for average level speech. This shows that I would likely need to use the volume control to increase the volume when speaking with soft talkers, which tends to be one of the largest areas of difficulty for people with mild to moderate hearing losses. 

Special Features

Frequency Bands

We also measured the frequency ranges each equalizer band adjusted. The bass adjustment controlled all of the frequencies between 250 and 3000 Hz, with a peak at around 2000 Hz. The mids adjustment controlled frequencies between 2000 and 6000 Hz, with a peak around 3000 Hz. The treble adjustment only made minor changes to the frequencies in the 6000 to 8000 Hz range. 

Noise Reduction

We also tested the noise reduction feature, which is the hearing aid’s ability to reduce the level of steady state background noise such as fan noise or a car engine. With the noise reduction feature turned off, we were able to tell that no noise reduction occurred. Once we switched it on, we measured approximately 9 to 10 dB of noise reduction, which means that you definitely would notice a difference in a noisy environment if you switched this feature on. For devices at this price point, this was a very good level of noise reduction.

Feedback Cancellation

To measure feedback cancellation, we cupped our hands around my ears to see how much whistling occurred, and there was no difference when the feedback cancellation feature was turned off or on. If whistling is a problem, you may need to switch to a more occluding dome or turn down the overall amplification levels.


Overall, the Soundwave Sontro OTC hearing aids are a pretty good option if you are a candidate for OTC hearing aids. They definitely will need to be adjusted to provide sufficient audibility, as they significantly underamplified sound at their first fit. If you find that you are not having the success you were hoping for after making adjustments to your hearing aids yourself, it is a good idea to enlist the help of your local audiologist to help you fine-tune your OTC hearing aids using real ear measurement to verify the output. If you still find you are not experiencing significant benefit, it may be time to discuss prescriptive level treatment with your hearing care provider.

Dr. Cliff's Pros and Cons for



Cliff Olson

Cliff Olson is an Audiologist and the co-founder of HearingUp and Applied Hearing Solutions in Phoenix, AZ. In addition, he runs and creates content for the popular DrCliffAuD YouTube channel.

Brianna Cole

Brianna Cole is a second year Doctorate of Audiology student at Arizona State University, where she is co-president of the Student Academy of Audiology chapter. She completed her Bachelor of Arts in Speech Science at the University of British Columbia. She started her career in Audiology at Applied Hearing Solutions as Dr. Cliff Olson's direct Audiology Assistant. A hearing aid user herself, Brianna is passionate about helping people hear their absolute best.

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