By 2020 there will be an estimated 50 billion electronic devices in the world. Only a small fraction of these will be making sounds that have been designed in any intentional sense. Many of these devices will be inherited. And many of us will be interacting with dozens of them in a given day.
Sound design can mean the difference between a noisy and cluttered world and a quiet, elegant one. It’s time that designers have the tools they need to make sound an integral part of the user experience.
Electric hum, produced by a wide array of electrical devices
Coil noise, a very high-pitched whine from monitors and CPUs
Vibrations, caused any appliance that has moving parts, especially when set on a surface that resonates with it
Fan noise, from computers, microwaves, heating/cooling systems, etc
Motor and tire noise, from passing traffic
Footsteps, furniture noise and paper shuffling from others in the space
Often active noise something that is only really “meant” to be heard by one person, but inserts itself into the hearing of many others as well.
Remember that one person’s signal can be another person’s noise.
As you seek to optimize the sounds in a user interaction, remember that the user may not be the only one experiencing the sound. Does it default to a usable state or does it break down completely?
Change the environment: Place a barrier between the source and listener, or, place acoustic treatment or active noise cancellation around the source.
Tune the source hardware: Change the speed of a fan so that its resonant frequency is in tune with the other devices in the kitchen.
Change the source hardware: Install a different speaker, ducting or coupling.
Mask the source, by playing another louder sound at the same time or noise just loud enough to obscure the transformer or fan noise.
Distract the user with a “rewarding” visual cue. If a device makes some kind of unpleasant noise (flushing toilet, grinding operation, high pitched whine), a simple, pleasant animation via LED or display may serve to reduce the annoyance of the offending sound.
Context: Design an interface that produces the right sound, in the right place, at the right time.
The acoustic environment - You need to take the surrounding environment into account. Are the walls large and blank? You will need to find something to dampen them. Plants, couches, rugs, and sound tiles are important.
Discretion - Knowing when to interrupt and when not to interrupt is important. A good server at a restaurant knows to ask you how the food is when you’re not in the middle of a giant bite of food. iPhones have a “do not disturb” mode that prevent notifications and calls from coming through during the middle of the night. These are all ways audio can be discreet or be absent when the environment is not good fit for them.
Audibility - Can you hear an important sound above others? Can you hear the laundry machine when it goes off in the basement? Is the tea kettle loud enough to let you know that it is done? One way to test this is to turn the sound down until it can’t be heard in its intended environment. Mark that point. Turn it back up to just before that point. That is your reference for that particular context.
Emotion - Does this washer and dryer set sound excited when it is done, or is it a mechanical and annoying buzz? You don’t want to be woken up in the middle of the night by an angry, undesigned clang. The speed of a tone can also create urgent behavior (an alarm clock) or a gradual alert (slower, calmer wakeup or buildup can create different interactions), and can help shape behavior.
Memorability - A sound that is memorable can remind someone in the future of dangerous or useful information. A light repeating tone in your car can signal that your parking brake is still engaged when you shift gears into drive after turning on your car. A custom tone set on your phone for your significant other can help let you know that the call is important as well as differentiate the tone from other sounds.
Listenability - Is the sound listenable? Is it too distorted, like the plane announcer’s voice through the speaker’s on an airline? Can you pay attention to it and remember it? Can you focus on it or is it so annoying that you’re just waiting for it to go away?
Extensibility - Extensibility is related to memorability. Can the sound be part of a collection of similar sounds, or is it just a one time thing? For instance, different objects such as tea kettles and toasters of the same brand family could have similar sounds, but it would be obvious for consumers that it comes from the same brand or brand family. Can the same sound work across multiple devices? Does the sound of a text message on your computer match the sound of it on your phone? Is it a good idea to have this happen, or should each device get a slightly different (but still related) sound?
DesigningWithSound.com is written and maintained by Amber Case and Aaron Day