Hear me out: Designing Sound for Mobile Games

First impressions matter – especially when people can decide to put you on mute, if not impressed. Whether it be a job interview or a performance on stage, your first move has a profound impact. The same goes for hearing the sound of your game for the first time.

Sound for your game includes all things audio; sound effects, music and dialogue, if applicable.

Working in the world of mobile game audio is an exciting challenge. This is a realm where the majority of players won’t play with the sound on (on average, 25–40% players play mobile games with the sound on). Whether it be because they are listening to music, are in a public place or some other reason, it’s likely they won’t have sounds on for their mobile games.

If a mobile game has poor audio, players are likely to mute it immediately—and they probably won’t turn it back on. This applies to both sound effects and music. Some games even launch without music, leaving them feeling incomplete; on the other hand, high-quality audio can really enhance a player's enjoyment and gaming experience. It has even been shown to positively impact player retention and session length.

Therefore my philosophy is always to make it so good they don’t want to turn it off – and this has been our goal for Merge Mansion, too.

There are many games that have great examples of high-quality soundtracks that live beyond the game and can create a comforting or encouraging soundtrack to play alongside. For mobile games, you want something that doesn’t get too annoying or fatiguing when repeated, as you want people not to be put off longer play sessions. This is generally why the soundtracks are often soft, pleasing and fairly relaxed for casual games like Merge Mansion. This still requires variation in areas such a key, emotion or even instrumentation to avoid repetition.

We’ve succeeded at Metacore to create this for Merge Mansion: our players' feedback about the music and sound design for Merge Mansion is really positive, and our soundtrack by Salla Hakkola won the NYX Game Award for Best Music in a Mobile Game 2023.For shorter play sessions, such as hyper-casual games, the music can also be high in intensity. In mid-to-hardcore games, especially non-mobile ones, this works differently, of course: they tend to have a broader dynamic range of intensity and emotion depending on the game.

This is why you should never release a product with 'placeholder music' or temporary sounds. When audio is considered 'bad,' it can mean many things: it might be low quality, the direction poorly chosen, the mix unbalanced so that some elements are too loud or too quiet, or the sound design or music could be completely missing.

This piece serves as a soundboard for the mysterious world of audio in mobile games and echoes our philosophies about sound at Metacore. Let’s tune in!

Great game audio starts with the right source

Where do sounds come from? Generally, there are two sources of sound effects: libraries or your own recordings. Great game audio always starts with knowing which source best fits your purpose. Source is king is a phrase used by many audio professionals in the field, which means that selecting the right source is always important before you begin adding all your effects and processing.

Sound libraries are exactly that. Collections of audio files that you browse, looking for the most appropriate sound effects required for whatever you’re working on. 

Recordings are whatever you have recorded yourself, whether they are captured in the real world with microphones or created digitally inside your Digital Audio Workstation (DAW). A DAW is the software you work in when creating or recording your sounds—for example, Pro Tools, Logic, Cubase, or, in our case, Reaper.

There are pros and cons to each. Generally, it is better to record what you can yourself, if you have the capability. This is because you’ll be able to capture the timing and “performance” of the sound that best suits your needs. Not only that, it gives you a unique signature to your sound.

That being said, you don’t always have the means to record original sounds. Whether that’s due to equipment, facilities, or source material (for example, recording vehicles or guns is not exactly accessible for most people), it often makes sense to use libraries. With most sound libraries, you also have the assurance that they have been recorded in high quality by someone who knows exactly how to capture high-fidelity sound effects, and that the audio files are cleaned and prepped for your use.

Most of the time, sound design is a combination of the two, depending on what you need to create.

When it comes to music, this can be seen as the same. You either record the instruments or use royalty-free music libraries. In Metacore’s case, we ensure the highest quality soundtracks by working with incredibly talented composers such as Salla Hakkola and Ilmari Hakkola, who have been collaborating closely with us on the award-winning Merge Mansion soundtrack for years.

You can find all of our award-winning soundtrack across streaming media, including Spotify, iTunes, and YouTube.

We always record with real musicians for our releases, to ensure the most authentic and faithful soundtrack for our players.

There’s more to great audio than dragging and dropping

One of the most common misconceptions about game audio is that you simply browse an SFX library, drag and drop a sound, and then move on to the next task. Well, that should definitely not be the case. While sound libraries are an integral part of the process, creating great audio requires much more than just dropping the beat.

For example, let’s use footsteps in a linear scene, such as an ad or cutscene. In a library, you have to find the right sounds, then the right footwear, chop them up, and finally make them work in sync with the characters in the scene. When you record them, you can not only ensure you record in sync with the character, but also get the impact of the footsteps correct, introduce your own variation, and make sure any scuffs are accurately captured too.

Even if you don’t have a professional studio to record in, you can use portable recording equipment to record sounds in a quiet, ideally treated space, or even in the right contextual environment out and about.

To summarize our key learnings: never simply drag and drop a sound into your project. Even if it’s the perfect sound source, you still need to place it thoughtfully within the scene and ensure it fits the context and narrative.

Telling Pocket Stories

“Pocket stories” is a term I picked up from a good friend and an industry peer, Rob Krekel. It has stuck with me ever since; as sound artists, we are constantly telling pocket stories, even if we don’t realize it. Whether it be birds flying overhead, traffic in the distance, or just the sounds of bushes and trees rustling, we are always embellishing the scene and finding ways to enhance the world around it in the same way that we experience the world around us. Every day, we hear brief sounds that pass us by, registering them either consciously or subconsciously. As an exercise, I’d recommend spending a morning actively listening to the sounds around you if you haven’t done so before. It’s surprising how much you can hear in the world when you truly listen.

The concept of pocket stories really helps to look at the sound world differently. When you focus on these miniature stories that are occurring all around you, even very briefly in some parts of the world, it adds more color and flavor to the soundscape and makes it even more interesting and believable.

Creating the world-class player experience with audio

To finish off, let’s highlight the most important part of our sound philosophy at Metacore – the player-first attitude that intersects everything we do. Whenever you're designing sound, you should always think about how it will work in context for the players who are enjoying your game. This also applies to how you implement and mix the sound in the game. Think about it this way: what is the most important thing for the player to hear moment to moment? What entices them? What makes them feel immersed in the magic of the game? What makes them connect emotionally with the world you’ve created for them?

When designing the sound for your games, it ultimately comes down to the player experience and what is most important for them to hear and why. Put yourself in their shoes – or ears.

This is also a golden opportunity to do things that go beyond just playing a sound. Within our games, there are lots of audio easter eggs that reference pop culture, movies, other games, memes, jokes and just all round fun things to give a sly nod to. As a Resident Evil fan, I took the opportunity to insert a brief piano sequence from Moonlight Sonata where it opens a secret compartment, similar to the secret passage in RE1. In another part of the game, I used a chord similar to Metal Gear Solid’s spotted “!” alert as another nod. There are many more, so maybe you can find them in the game yourselves…There are so many opportunities to be creative in this role that it’s always worth having fun with it. Of course, in many instances, you have to create your own interpretation for copyright reasons, but there are still plenty of ways to design sounds or music that serve as a love letter to other media.

At the end of the day, we’re making games to entertain players. So, let’s make it sound like we’re having fun, too!

Sam Hughes is a BAFTA-winning sound designer and the Audio Lead at Metacore. He has been working in sound for over a decade.