In this section
As seen in Section 3.1.8 “Provide auditory cues”, sound plays an important role in the wayfinding experience of vision impaired people, whether it is environmental, e.g. a car passing by, or pre-determined, e.g. any sound design component such as a keypad sound or alert. The predetermined auditory information for digital wayfinding, i.e. the sound design elements, comes in two forms:
- Notification alerts, which are sound alerts that precede the audio instructions
- Synthesised voice commands, which are computer-generated voice commands often associated with the accessible use of a modern smartphone or computer, e.g. VoiceOver mode on iOS or TalkBack mode on Android. These are vital tools for vision impaired people.
This section includes mainly guidelines about the sound design of notification alerts, as the synthesised voice commands are native to the mobile operating system.
2.1 Using sound to attract people’s attention
Using sound to attract people’s attention ahead of an audio instruction is helpful for the following reasons:
- It allows users to have their attention on the environment and to focus on the technology only when they are required to listen to an instruction. If there is no clear differentiation from the audio instruction and the environmental noises, they will be constantly focusing on the technology for fear of missing an audio instruction.
- Similarly, without the use of sound to attract the user’s attention environmental noises may override the audio instruction resulting in users missing the audio instruction.
- In addition, requesting the user’s attention only when it is needed enables them to engage in conversation with companions. The sound will signal to them that an instruction is coming up, giving them the time to shift the focus of their attention.
2.2 Using different notification alerts for different purposes
Consider using two core notification alerts that serve different purposes, which are the following:
- General Notification Alert is a short 2-note alert heard immediately prior to all audio instructions, excluding the “Journey Completed” audio instruction (see below). This notification alert prepares vision impaired people for any upcoming voice instruction, as seen in Section 3.1.8 “Provide auditory cues”. The proposed Wayfindr sound can be heard and downloaded below. It is also integrated in the Wayfindr Demo iOS App v0.4.
- Journey Completed Notification Alert is a short 3-note alert heard immediately prior to any voice command that confirms the scheduled journey has been completed. The proposed Wayfindr sound can be heard and downloaded below. It is also integrated in the Wayfindr Demo iOS App v0.4.
The notifications alerts should alert the user without causing undue alarm or stress. They should be minimally designed functional sounds that are simple and concise, providing reassurance, whilst preparing the user for the imminent audio instruction. The proposed Wayfindr sounds follow these principles and it is encouraged to be used in digital navigation services.
The two Wayfindr notification sound alerts above act as a coherent pair, yet they are varied enough to suit their individual function. The identically pitched 2-notes used for the general notification alert are short and generic, acting as a quick-fire prompt to the upcoming voice instruction, whereas the 3-notes used for the journey completed alert have a rising pitch, indicating resolution – the successful completion of the intended journey.
Paired functional sounds (or UI sounds) are common practice, especially within the context of smartphone use – renowned examples include the “Listen” and “Confirmation” sounds used for the personal assistant “Siri” in Apple iOS, or the similarly-paired “Google Now” sounds. Other examples of paired UI sounds typically include an on and off, lock and unlock, and connect and disconnect pairing. The paired sounds will typically be similar in tonality or instrumentation (sharing design principles that contribute to a consistent UX), but varied enough in their form to communicate a specific function.
2.3 Distinguishing notification alerts from other sounds
The notification alerts should be audible within a noisy environment and be distinguishable from existing phone operating system alerts, ensuring the wayfinding experience is unique, consistent and recognisable.
Suggestions for further investigation
The following paragraphs are not guidelines but suggested areas for future investigation through user research.
s2.1 Using new sound alerts for more specific purposes
Additional notification alerts can be considered for future updates of the Open Standard – such as specific warning alerts, categorised alerts for different objects or any other contextually-aware notifications.