The soundhole is a huge part of the design of an acoustic guitar, usually sitting right in the middle of the soundboard. While it might seem like its only purpose is to swallow picks and never to let them out again, it actually plays a crucial role in the functioning of your guitar.
Soundholes amplify the sound of your guitar and help create it. A soundhole focuses sound waves on a single spot and directs them toward the listener, which makes the sound louder. A soundhole also makes the soundboard lighter, allowing it to vibrate more easily.
This article will examine the role of soundholes on acoustic guitars. We’ll also mention their role on electric guitars, and we’ll examine why you might sometimes have to cover your soundhole.
Related: do acoustic guitars need pickguards? the facts explained, best guitar tone woods, and best guitar necks. For the full overview, see our complete guide to guitar anatomy.
How Guitars Create Sound
In a nutshell, sound is vibration. When an object vibrates, it stirs molecules of air, which in turn bump into their neighbor molecules. As the molecules bump into each other, sound waves are created. This motion travels to our eardrums, which also vibrate.
What we hear depends on the strength of the initial vibration and the medium it travels through. This is easily observable in guitars. Strumming harder will always create a louder sound, and different materials can create different sounds.
When it comes to acoustic guitars, the sound is created by picking or strumming the strings and causing them to vibrate. The vibration is then transferred to the guitar’s bridge, which causes the soundboard to vibrate.
These vibrations make the air in the guitar’s body vibrate as well. The vibration is released through the sound hole, which gives us the sound we love.
Electric guitars also depend on vibrations, but the mechanism is vastly different. The strings vibrate, of course, but these vibrations are picked up by the pickups and sent through wires to the guitar cable and then to the guitar amplifier, which makes the vibrations loud enough for us to hear.
The most essential thing to remember for understanding the purpose of a soundhole is vibrations. Let’s examine more closely what a soundhole does with them.
The Role of the Soundhole in a Guitar
We know that an acoustic guitar produces sound when it vibrates and the vibrations of the air inside the guitar are released through the soundhole. But the soundhole is not merely there so that air has somewhere to escape. Its role is somewhat more complicated.
A common explanation is that the soundhole amplifies the sound created by a guitar. However, it doesn’t exactly amplify it, as it does not add any energy to the sound. It merely focuses the soundwaves on a small surface and directs them.
This effect is often compared to putting a phone in a bowl while playing music. The music will sound louder despite not getting any additional energy. The soundwaves will be concentrated and directed to a particular location.
Instead of scattering everywhere, the soundwaves travel to a particular location and directly to the listener. Simply put, more soundwaves reach the listener’s eardrum instead of getting lost around them.
In addition, the soundwaves from the guitar’s body will vibrate at the same frequency as the strings, creating a uniform sound.
This effect makes the sound seem louder even though no additional energy is added to it. Nevertheless, the final effect is what’s important, and the easier it is to hear the guitar, the better it is for the player and the audience.
Directing and channeling the soundwaves is the primary role of the soundhole. Without it, an acoustic guitar would be barely audible and sound muffled—not particularly enjoyable.
Apart from this main role in amplifying the sound, a soundhole may play another, slightly less significant role. Creating a soundhole in the soundboard makes the soundboard lighter. The reduced weight makes it easier for it to vibrate and thus produces sound. While this is not the main reason there are soundholes on acoustic guitars, it adds to their usefulness.
Why There Are Different Soundholes
The most common soundholes are just big round holes with some decorations on the edges. This gets the job done very efficiently and it’s not particularly difficult or expensive to make. For that reason, it is the most common soundhole shape, but some variations exist.
The variations are there primarily for aesthetic reasons, but they sometimes change how the guitar will sound. These sonic differences are not usually big, but they can still be important.
Some other soundhole shapes include:
- F-holes
- Oval holes
- Multiple small holes
- Offset soundholes
- D-shaped holes
Let’s briefly examine these types of soundholes.
F-Holes
F-holes are most common on violins, cellos, and similar instruments. They were later copied by guitar manufacturers seeking to change and improve the sound of acoustic guitars. In addition to looking really stylish, these guitars have a more twangy and mellow sound.
For example, B.B. King was a famous lover of f-hole guitars. They’re obviously great for blues, but also rockabilly and other genres that don’t require aggressive riffing.
F-holes are common on archtop acoustic guitars and hollow-body electric guitars, giving them a recognizable shape.
Oval Holes
Oval soundholes are particularly popular among jazz players. Django Reinhardt was a legendary jazz guitarist who played a guitar with an oval soundhole.
The sound difference is not that noticeable, but some players say that they have more sustain compared to f-holes and that there are more low-mids and less top in the tone.
Multiple Small Holes
Some Ovation and Godin guitars are known for having multiple smaller holes strategically placed on the guitar. These holes are typically offset, changing the tone further. There are also guitars with two small soundholes: one at the top of the guitar and the other at the bottom.
Offset Soundholes
Some guitars have smaller soundholes placed at the top of the guitar soundboard instead of under the strings. This makes them look spectacularly cool, but this design choice has an influence on the sound.
These guitars sound slightly mellower and warmer than regular guitars. This makes sense because the air can’t escape the guitar that easily, and thus has to travel more around the guitar’s body.
D-Shaped Soundholes
In some rare cases, the soundhole on a guitar can be D-shaped. This is quite rare nowadays, and only present on the so-called gypsy guitars. These soundholes are present in part because of tradition, but they’re also adapted to specific types of music—for example, gypsy jazz.
A common piece of wisdom says that D-shaped soundholes work best for rhythm because they have a stronger bass response, while oval ones are best for lead. However, you’ll often find cases where this is reversed.
The truth is that it’s mostly a personal preference—besides, the difference in sound between the two shapes is minimal.
When To Cover a Soundhole
You may have noticed that guitarists sometimes play with the soundhole covered by a circular piece of rubber. This is a feedback suppressor, and it’s there to eliminate feedback on electric-acoustic guitars. It does a terrific job at this, and it can save you many headaches during a gig.
It might also be a way to slightly dampen your guitar and make it less loud. This can be helpful if you’re playing in a flat or dorm and don’t want to disturb your neighbors. A feedback suppressor might remove some stubborn bass frequencies that penetrate walls easily. Your neighbors might not hear you at all, or at least they won’t hear you as much.
If you want to silence your guitar, getting an acoustic guitar silencer is a great choice. It costs next to nothing, but it completely eliminates your guitar’s sound, so you can jam even when the people around you are asleep.
No-Soundhole Guitars
Considering the importance of soundholes on guitars, it’s logical to assume that it’s impossible to build a guitar with no soundhole. But even though it’s not easy to pull off, it’s certainly possible. Guitars with no soundholes exist, but they are few and far between.
Those guitars sound a bit muted, less open, and less bright. This does not mean they sound bad—they’re just different, and for some musicians and types of music, that kind of sound might be