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At a glance
In the video above, I compare the Dohm Uno and Rohm and then play through all of their sound options. They are both easy-to-use white noise machines that keep things simple rather than including lots of extra features. They create the white noise differently though, so it helps to understand the key differences between them.
The Dohm Uno doesn’t use recordings like many white noise machines do. It has a real internal fan that forces air through small holes to produce the sound. It’s a relatively gentle sound compared to most white noise machines, so it’s more effective for relaxation rather than masking external noise.
The Rohm has three digital sounds rather than a mechanical fan: bright white noise, deep white noise, and ocean surf. Its small size and internal rechargeable battery make it a good option for travel or placement in a child’s bedroom out of their reach.
This written article isn’t a word-for-word transcript of my above video. I edited it so it’s easier to read and find what you’re most interested in.
To clear up any confusion, the Dohm Uno and Rohm are now made by the company Yogasleep. They used to be called Marpac, but rebranded a few years ago.
They are one of the oldest manufacturers of white noise machines, stretching back to the 1960s. In fact, some of the current devices now sold under the YogaSleep name since the company rebranded are still based on the popular original Dohm model.
I decided to compare two of their models in this review so you can see the main differences between one of their larger machines that uses an actual fan and a more portable device that plays white noise recordings instead.
In the photo below, you can see the Dohm Uno I used in the video still has the previous brand name written on it – Marpac. You may still find second-hand ones with this name.
The Dohm Uno is a simplified version of the original Dohm, which was itself already remarkably simple!
It’s a little smaller than the previous Dohm versions, which is good as the original was quite bulky for the bedside table. Despite being smaller, it still has enough weight and grippy feet to stop it from sliding across the table when you use it.
There’s just one button – the on/off button. There’s no volume control, no timers, no additional sounds. The Uno doesn’t even have the dual speed option that the original Dohm did – hence the name ‘Uno’.
When you turn it on, a mechanical fan starts up, and the resulting air is pushed through gaps in the casing of the device. The only option you have is to turn the casing, which adjusts the sound the air makes as it exits the Uno. You can listen to it in action in my video above (starting at 0:30).
I like the sound the Uno produces. It’s natural, gentle, and relaxing – much more so than the wind or fan recordings that most white noise machines provide. And it’s interesting that you can finetune the sound of the air, albeit not by that much.
Sound masking and volume
Although I enjoy the soothing sound, it’s perhaps a little too gentle to mask loud external noise. So I think the Uno is one for relaxation rather than a tool to combat your neighbor’s music or traffic outside.
The Uno is hardwired with a long cable and standard wall plug. There’s no wireless option, which along with the size, makes it far less practical for travel than the Rohm.
My main issue with the Uno is the lack of features. I understand that it’s intended to be a no-frills, simple device. And that’s exactly what might appeal to some people. But I think an auto-off timer would be a great addition.
Being wired, it’s obviously limited in terms of placement. And despite being smaller, it’s still larger than many other sound machines.
Below, you can see how small the Rohm is when placed on my bedside table next to a standard small glass.
The Rohm couldn’t be more different than the Uno. The most obvious difference is that it’s much more compact: it’s small, lightweight, and hardly takes up any space in a bag when traveling.
The reason it’s so much smaller is that it doesn’t have an internal fan. This is a key difference to understand when comparing these sound machines.
There are four buttons: on/off, volume up and down, and sound choice. It also comes with a small lanyard so you can hang it up rather than place it on a table.
The Rohm has three different sounds to choose from:
- Bright white noise
- Deep white noise
- Ocean surf
I couldn’t actually find much information regarding the way the sounds are produced. I’ve seen descriptions like ‘digitally generated’, but the company doesn’t provide a clear explanation on their website. I refer to them as recordings in the video, though I’m still not totally sure if they are recordings or are created internally so the surf sounds avoid any noticeable looping.
The important point though is that all three sounds are good quality. Personally, I like the deep white noise best as it’s more relaxing to my ear.
Sound masking and volume
The little Rohm really surprised me with its volume. For such a tiny device, the speaker can certainly roar at the maximum volume. So this might be useful if you’re traveling and find to your horror that your hotel room is right above a busy street.
I found it can reliably mask pretty much all noise from outside the house, whether placed near your bed or by the offending non-soundproof window.
The Rohm comes with a micro USB to USB cable, so you can play it from a USB hub or a computer. Conveniently, it has an internal rechargeable battery, so you can place it wherever you like in a room without needing to be plugged in.
The length of charge will depend on the volume you play it at, but I’ve easily gotten a whole night out of one charge. The company says it takes four hours to charge and that you should get up to eight hours of play on a full charge.
Marpac were long known for their internal fan design, so I think it’s a shame that they don’t include a gentle fan sound with the Rohm. And just three sound choices is very limited compared to even the most basic of sound machines, which tend to start at around six.
The buttons need some getting used to. The power button needs to be held for a couple of seconds. And if you noticed in my video, I sometimes had to turn the Rohm sideways to change the sound option, which was strange.
Which one is best for you?
Both of these sound machines are good choices, depending on your preferences and what you want to use it for. I don’t think it’s a case of saying that one is definitively better than the other.
Here’s who I think might like each one most:
- If you find gentle fan sounds relaxing, but don’t want to use a large fan in your room.
- If you don’t plan on transporting it anywhere.
- If you don’t need other white noise or nature sounds.
- If you value simplicity over having lots of options.
- If you want a small, lightweight white noise machine to take on your travels.
- If you need louder volume levels.
- If three sounds are enough for you and you don’t need endless variety.
- If you prefer a wireless device with an internal battery so you don’t need to keep it plugged in all night.