New design process for noticeable, but pleasant sounds
Track 3: what the beep?
The goal of this research is improving alarm sound design, focusing on the paradox of noticeable versus pleasant sounds. The characteristics of annoying sounds correspond in large extend to the characteristics of noticeable sounds. Therefore it is difficult to design an alarm sound, which is noticeable, but not annoying. A lot of studies are conducted along aspects which make sounds annoying and several guidelines are described for designing noticeable alarm sounds. However, no data is conveyed about the combination of these characteristics linked to sound design. In this study an existing design process for alarm sounds is adjusted regarding to pleasantness and noticeability of sounds. Hereby methods to analyze and test pleasantness and noticeability of sounds are added to the process. As a result this paper suggests a new design process which can be used to design an alarm sound considering these aspects.
product sound design; alarm sound; annoying sounds; noticeable sounds; design processes
Most of the time alarm sounds are not optimal designed, because in the majority of cases the context of the user is not taken into account. Edworthy (2006) found that in consequence alarms are often too badly designed resulting in annoying, not effective sounds. Schmidt & Baysinger (1986) pointed out that a pleasant sound to report a complication can be more effective during an emergency. However, the alarm sound should still be clearly noticeable, so that it cannot be missed.
The perception of annoyance may be very personal and subjective, but research has shown that there are some characteristics of sounds that influence this perceived annoyance. (Steele & Chon, 2007). The research of Steele & Chon (2007) found that loudness is the most important determinant of annoyance in respect to sound. They also revealed that the wider the bandwidth, the more annoying the sound is perceived. Higher frequencies and modulations increase the perception of annoyance as well (Genuit, 2001). A modulation is a change from one tone to another. Besides the type of sound, there are a many other factors that influence the perception of annoyance. One of these factors, revealed by Maris et al. (2007), is the ability to influence the sound. Another study posited that age is also an important aspect for determining the perception of annoyance. (Botteldooren & Verkeyn, 2002).
Obviously, the noticeability of an alarm sound is better when the volume of the sound is higher. Edworthy (2006) pointed out some other characteristics of clearly noticeable alarms sounds, like high and low frequencies, harmonics and discontinuous sounds. Hereby alarm sounds are respectively easier to localize, more resistant to masking by other sounds and less presumable to interfere with communication. Harmonics are sounds with frequencies that are a multiple of the fundamental frequency. Another component which makes a sound more clearly noticeable, is the variation in more than only pitch (Edworthy & Meredith, 1997). Namely, if a sound alters in more than just tone, for instance frequency, the ability to distinguish it from other sounds increases. Besides that, environmental sounds and auditory icons are easier to learn and retain (Leung, 1997; Ulfvengren, 2003).
Similarities annoying and noticeable sounds
There is a lot of literature written about designing noticeable alarm sounds and about annoying sounds. However, there is barely literature which compares these two characteristics of sounds. Nevertheless, a lot of characteristics of annoying sounds are identical to the characteristics of noticeable sounds, see figure 1.
Figure 1. Characteristics which make sounds annoying as well as noticeable.
As you can see in this figure, loudness is an...