Making Good-sounding Audio for Mobile Games
by Antti Kananen
Sound in mobile games is a tricky issue. On one hand, you can’t have a game without sound, sound is part of the whole gaming experience, the much needed cherry on top of graphics and gameplay. On the other hand, mobile games are often played without sound and even when the sound is on, the speakers on mobile devices don’t really offer the best playback experience. Mobile games really have to have a different approach to sound design to actually make sure the player can hear the full range of your sounds.
One basic tenet of sound design for games is that your sounds have to match the visual look and feel of your game. In the case of Crashing Season, it would be a cartoony look with the gameplay consisting of action-filled “crashing”. So in Crashing Season, the sound design would have to sound cartoony, silly but also with meaty “thwack” sounds. Basic enemies in the game don’t make that much noise, since the sheer volume of these enemies on screen that can be achieved in a single session would make any repetitive sound they make very annoying, very quickly. On the other hand, the boss enemies of Crashing Season do need sounds, as indicators of their status when they’re off-screen as well as to set the mood for the boss fight.
The first boss of the game is the Lumberjack, who starts the fight in a gigantic tree harvester. For the harvester, the sound was a mix of a lawnmower engine, a running buzz saw and a tractor. The second stage of the fight has the lumberjack outside of his harvester, where he uses his personal chainsaw. The sounds for this need to be even more threatening since the boss is more aggressive on foot, so in addition to the lawnmower, buzz saw and tractor, the sound of a 50cc motorbike engine was included for added texture. In between chainsaw attacks, the lumberjack boss enters an exhausted state, and thus becomes vulnerable to attack. Visually this is clear but he also needed a heavy breathing voice to add a vocal cue. The breathing sound is the exaggerated breathing of our sound designer, the pitch of which is lowered to reflect how the lumberjack is quite a large man. To ensure that the player can actually hear the breathing from the mobile device speakers, a different breathing sound was added to bring texture.
As stated above, mobile games need to have sounds even though some players may mute them. These sounds also need to complement the gameplay, which means that you can’t have bad quality sounds since they may just as well ruin an experience much like bad gameplay can. Whether your user uses headphones or just the phone speakers, you, as a sound designer, can cater to both.
The biggest challenge is bringing the low end of the sound spectrum to a hearable level. The bass sounds simply cannot be properly replayed through basic mobile device speakers, often resulting in a tinny, treble-heavy sound. This should naturally be avoided for its unpleasantness. One way to make the low frequencies sound better and make them easier to hear is to use saturation, which brings the higher frequencies of the bass sounds to the front. This makes the ear realize that the bass sounds are there, even though you still can’t hear them that well. You have to find a balance between headphones users and users who use the device speakers.
When you’re developing a game, usually on a computer with real speakers or quality headphones, you may use bass heavy sounds that sound good at the time. However, these sounds will not be played in-game as you heard them. Plan your sound design for mobile devices with this in mind.
Find the right frequencies for your game audio and make full use of them. Use saturation to mimic the effect of the lower frequencies in sound design.
To find out more how we at Koukoi Games are finalizing Crashing Season, stay tuned for more updates and remember to play the game when it comes out for iOS and Android devices globally! The game is currently available for Android devices only in CAN & AU. Also, sign up in our mailing list and receive a free digital artbook and printable papercraft character!（source：Gamasutra）