Solely a white noise machine, the Marpac Dohm has no additional sounds or features, but it is proficient at masking noise to create a soothing and quiet environment for concentration or rest. An actual fan inside this sleep machine creates a continuous flow of white noise that sounds natural and fluid.
Although the Dohm has a limited feature set, it is one of the best at masking distracting sounds. The natural white noise generated by the fan creates a tone that quickly becomes ambient, fading into the background like an invisible net that filters distracting sounds before they reach your ear. The white noise is subtle, but its noise masking abilities are apparent. During our testing, the white noise generator virtually masked all traffic sounds from the street outside our testing facility. It was also proficient at masking dialogue from the television outside of our test room. This white noise sound machine is subtle enough that you can run it at your office desk and block your co-workers' chatter without distracting your office neighbors. Since it doesn't operate on looped sounds, you won't become distracted or kept awake at night by the white noise.
Out of the box, this white cylindrical sleep machine looks unlike any other white noise machine we've reviewed. Its half-dome shape twists to adjust the tone and volume of the white noise. Outside of the on/off button, there are no additional buttons or displays. The only sound that the Dohm makes is white noise.
The white noise generator has two fan settings: slow and fast. The tone of the noise can be adjusted by twisting the top and body of the machine to change the airflow within the Dohm. Opening all of the air passages creates louder white noise, and decreasing the air passages creates a quieter tone. It is important that you take a moment to twist and adjust the sound machine to find the most soothing white noise for you.
A power cord runs from the back of the sound machine and is the only power source available. This sound machine does not have backup battery power like a few of the other sound machines we reviewed, including the HoMedics SoundSpa.
Many other sound machines have multiple features such as alarm clocks, timers and displays. The Marpac Dohm simply generates white noise to create a relaxing environment – and it does it well. Don't let the lack of features deter you; this sound machine is well worth the small investment.