The SoundsRight CAPTCHA

Abstract

In this paper we describe the development of a new audio CAPTCHA called the SoundsRight CAPTCHA, and the evaluation of the CAPTCHA with 20 blind users. Blind users cannot use visual CAPTCHAs, and it has been documented in the research literature that the existing audio CAPTCHAs have task success rates below 50% for blind users. The SoundsRight audio CAPTCHA presents a realtime audio-based challenge in which the user is asked to identify a specific sound (for example the sound of a bell or a piano) each time it occurs in a series of 10 sounds that are played through the computer's audio system. Evaluation results from three rounds of usability testing document that the task success rate was higher than 90% for blind users. Discussion, limitations, and suggestions for future research are also presented.

reCAPTCHA challenges and the production of the ideal web user

“…The W3C also noted that "a design pattern that expects multiple attempts from users as a matter of course is arguably inaccessible by design to persons living with an anxiety disorder as well as to many living with a range of other cognitive and learning disabilities" (Inaccessibility of CAPTCHA, n.d.). The sorts of limitations of reCAPTCHAs have been well-documented, but the technology's industry lore and prioritization of data production have impeded the implementation of more accessible and usable options (Gafni and Nagar, 2016;Lazar et al, 2007Lazar et al, , 2012Lazar et al, , 2012Rosales and Fernández-Ardèvol, 2020). The only people who meet reCAPTCHA's criteria of an authentic user are those who meet certain standards of ability and therefore can be productive and valuable sites of labor extraction.…”

“…There have been limited responses to these accessibility and usability problems, such as the development of audio-based CAPTCHA challenges. However, these alternatives tend to be a significantly worse user experience, requiring much more time and having a lower success rate for humans to solve (Lazar et al, 2012). Additionally, these audio CAPTCHAs still fail to accommodate people with intersectional disabilities, such as deaf-blind users (Wentz et al, 2017).…”

“…Additionally, these audio CAPTCHAs still fail to accommodate people with intersectional disabilities, such as deaf-blind users (Wentz et al, 2017). There has been some initial work toward the development of CAPTCHA challenges with improved accessibility and usability, but these versions have yet to be widely implemented (Lazar et al, 2012). Google’s reCAPTCHA remains the dominant CAPTCHA used throughout the Web, and it has yet to incorporate these types of improvements.…”

“…In this sense, the reCAPTCHA can be understood as a form of free labor, where the ‘knowledgeable consumption of culture is translated into productive activities that are pleasurably embraced and at the same time often shamelessly exploited’ (Terranova, 2000: 37). reCAPTCHAs are somewhat different, in that they are not necessarily pleasurable to solve; in fact minimizing user frustration and the time required to solve the challenge are typical goals in CAPTCHA development (Fortunati et al, 2019: 1861; Lazar et al, 2012: 2268). However, scholars have drawn on algorithmic game theory to note that there remains a motivational component to reCAPTCHAs; users want to interact with a site, and they are required to solve the challenge in order to do so (Farenzena et al, 2016; Mühlhoff, 2020).…”

“…And even when the audio is correctly made available, users with certain forms of cognitive disabilities may find audio CAPTCHAs to impose cognitive overload and require directed focus which may not be possible in all settings – such as with mobile devices or in noisy environments (W3C Working Group, 2019: 2.1.2). Alternative options such as Lazar et al’s (2012) ‘SoundsRight CAPTCHA’ do offer improved accessibility and usability for a greater number of users. Additionally it is possible for a website to better meet the abilities of more people by incorporating multiple types of CAPTCHA challenge, which Bell (2012) has shown can also improve overall website security.…”