Developing Mobile Applications For The Visually Impaired Computer Science Essay

With the recent significant growing of smartphone users, there is a demand for nomadic applications to be useable by all market divisions. This undertaking looks into orienting nomadic application interfaces to the visually impaired smartphone user. We study the Android Mobile runing system and technological challenges faced by the visually impaired, and farther implement findings into a smartphone music participant application. We look at the different techniques and characteristics that can be implemented to diminish the cognitive burden on the user, in order to simplify usage of smartphones. Finally we identify the best pattern for nomadic application development for the visually impaired, and through consequences from proving we confirm its effectivity.


Purposes and aims

The purpose of this undertaking is to execute an probe into the usage of smart phone characteristics in order to do nomadic applications and general use of the smart phone more accessible to blind and visually impaired users. Previous attacks into nomadic development for the handicapped will be scrutinised and we identify strengths and failings in these. In making this it is hoped that future nomadic application development for the blind and visually impaired will profit from the findings, therefore doing smart phones more accessible and the smart phone market more inclusive. Findingss are so, where possible, implemented into a music participant application for smart phones running the Android Operating System. This is an application besides designed for usage by the general user market. An iterative development procedure was employed, with feedback at each phase for the paradigms.


In this undertaking we aim to provide to the demands of the visually impaired users of Android smart phones in peculiar, as it can be observed from assorted beginnings that this is a urgent issue. “ Even as every mobile-phone shaper is trying to come up with the latest and the most fashionable version of a touchscreen phone, visually-impaired people seem to be mostly ignored by the makers aˆ¦only Apple ‘s iPhone is to the full accessible right out of the box to the visually impairedaˆ¦ However, no other smartphone presently comes near to offering such engineering for the visually impaired. ”[ 1 ]

Although present package systems are frequently really sophisticated and user-friendly, their usage frequently poses an incommodiousness for visually impaired people. This can be attributed to the graphical interface and absence of characteristics carry throughing the specific demands of those with sight jobs. Basic handiness services are represented by address synthesist and screen magnification package, used to obtain information from computing machines. The present development in human-computer interaction and spoken linguistic communication duologue systems brings new chances for betterment but besides new jobs. For illustration, address acknowledgment is notoriously erring. This unfortunate fact holds great importance for the visually impaired user, particularly emphasised by the point that for this group of people, computing machines are one of the most of import beginnings of information[ 2 ].

Overview of the study

This study is organised asaˆ¦ [ brief description of contents ]

2 Background

Smart phones

Traditional nomadic phones offer a limited scope of characteristics for the user, frequently non falling far outside capablenesss to direct SMS, make calls and possibly take exposure and drama music. However a smart phone is possibly better described as a hand-held personal computing machine. Typically, CPU treating velocity will run from 600MHz to 1.2GHz with RAM of around 600MB[ 3 ]. This is non dissimilar to specifications for larger personal computing machines found in the place. Smart phones will hold both internal and external memory in the signifier of a memory card available in different sizes.

Operating System

The pick of the Android operating system was mostly due to the fact that unlike Apple ‘s iPhone OS, Android allows developers to freely develop unfastened beginning codification without limitations[ 4 ]. This means that developers can entree and construct on the work of others. Other factors besides influenced this pick, as we will now research.

Android is a nomadic operating system developed by Android Inc. , a house subsequently bought by Google Inc. It is based on the Linux operating system. Presently, about 70,000 applications are available on the Android Application Market. The Android package system consists of Java applications running on a Java based object oriented application model.

Android histories for 29 % of all active smartphones in America ( fig 2.2.1 ) . With this success in the market, more and more smartphones are set to be released in the coming old ages.

[ Fig 2.2.1, Beginning: The Nielsen Company ]

2.3 Mobile Applications

Possibly the most popular merchandising point and alone characteristic of smart phones is their functionality to download and put in applications ( abbreviated to ‘apps ‘ ) . Most smart phone runing systems offer entree to a market where applications made by commercial and independent developers are available for free or paid download. For illustration, the iPhone has its ain app market, as does Nokia hold the Ovi Store. The user is able to shop through, select and download assorted apps

The Android market in peculiar does non choose apps to come in into the market based on their unity and selling possible ; instead it elects to utilize a user evaluation based system, where apps are labelled by their user evaluation and reexamine. This is an inducement for both experient and possible developers to bring forth applications which they can so portion.

2.3.1 Security

Security is a considerable factor when selling applications. When installed, an application may hold entree to confidential information, every bit good as permissions to do calls and entree the cyberspace. With some application markets, an app will undergo strict security cheques before it is released to the populace. With Android ‘s Marketplace, these security cheques are non in topographic point, alternatively the user is given the pick of whether or non to download an application. All permissions the application requires are listed, and the user makes their pick from this[ 5 ].

2.3.2 Efficiency

Efficiency is a cardinal factor in nomadic development. This requires applications to lade and run rapidly. It besides means that resources must be used with cautiousness. Chong reinforces the importance of codification being optimised every bit far as possible, since nomadic phones being of ‘small size, have limited memory[ 6 ]. ‘

Music Player Applications

Whilst Apple seems to command the market of portable music participants[ 7 ], consumers invariably look elsewhere to new, advanced agencies to listen to music. As the nomadic phone market becomes more competitory, trade names offer more and more characteristics to clients. The media participant characteristic has been common in nomadic phones for many old ages now, nevertheless, infinite and size restraints frequently persuade the client to put farther in a portable music participant.

The recent entry of smartphones into the market sees clients with the handheld power to carry through a great figure of undertakings, rendering a great figure of other electronic devices otiose. The ability to play music may be merely one of the characteristics of a smartphone, but still perchance stands as one of the most coveted.

In an age where nomadic phones are omnipresent, the survey of nomadic phone music participants is a worthwhile 1. This is due to a figure of factors. Continuous betterments of battery life, expandible memory, better sound quality and ability to play different music formats are all promotions that favour the replacing of portable music participants with smart phones. Other characteristics include the debut of 3.5mm earphone sockets on smart phones, leting the usage of mundane earphones to listen to music, and non curtailing this to the maker ‘s alone headset.

We look at the two most popular music participant applications available on the Android Market. Popularity here will be measured by the figure of active users at the clip of survey. Both applications have been released by commercial developer squads and as such are available at a monetary value.

MixZing Player

MixZing claims its music participant application to be the “ most advanced music participant on any platform ”[ 8 ]. It boasts a clean design having advanced characteristics such as the “ Mood Player ” which automatically fills the play list with recommended vocals. Although described as clean and easy to utilize, it is apparent at a first glimpse that the interface might be construed as reasonably complicated. The chief screen focuses on album art, and buttons are little and hard to utilize on smaller smart phones. User feedback is by and large positive, and any ailments are sing the slow velocity and occasional unresponsive controls, every bit good as ailments about the monetary value ( ?3.99 ) .

Winamp Music Player

Winamp is a media participant foremost seen on personal computing machines before traveling to mobile devices.[ 9 ]Besides one of the most downloaded applications on the Android Market, it portions many of the same features as the MixZing participant. These include the intuitive play list Godhead, every bit good as the slightly crowded interface. Feedback for the application is by and large positive, although some users comment on the interface, “ buttons unresponsive at lock screen controls. ”[ 10 ]The deficiency of lock screen characteristic is mentioned frequently.

Literature Review

Here we study antecedently completed research documents and articles associating to the undertaking. We find that similar undertakings have been attempted in the yesteryear, and we will compare these attacks to see the successful elements which will profit the application.

Ocular Damage

Ocular damage is an umbrella term covering any type of ocular disablement. These can be partial sightlessness, loss of depth perceptual experience, coloring material sightlessness etc. Those who are wholly blind can non be categorised as visually impaired. There are assorted causes for ocular damage, such as loss of ocular sharp-sightedness, loss of ocular field and optic motor damage. Ocular sharp-sightedness is a step of the vision lucidity, in each separate oculus and in both working in concurrence. Ocular sharp-sightedness of 20/200 or lower is classified lawfully blind. ( See Fig 3.1.1 for categorization of ocular damage ) . Ocular field is the scope of sight without traveling eyes or caput. A ocular field of under 21 grades is classified as lawfully blind. Ocular motor damage refers to the trouble of the oculus musculuss in executing basic maps such as fixating vision, and following or seeking after objects. In some instances the individual is unable to see a 3 dimensional image[ 11 ]. Nordin references that ocular damage can non be assessed merely in respects to ocular sharp-sightedness, but other factors which must be taken into history are self-generated motion of the oculus ( optic motility ) , color sensitiveness and coloring material sightlessness[ 12 ].

Therefore ocular damage can propose a scope of oculus conditions including but non limited to: close eyesight, far eyesight, astigmia and coloring material sightlessness. In this undertaking we will be concentrating on support for a bulk of these conditions by accommodating the user interface to be used with minimum ocular interaction.

[ Fig 3.1.1 Classification of ocular damage, Adapted from Colenbrander, 1999 ][ 13 ]


Ocular Acuity Score

( Near- ) Normal Vision

Range of Normal Vision

20/12.5 – 20/25

Near-Normal Vision

20/32 – 20/63

Low Vision

Moderate Low Vision

20/80 – 20/160

Severe Low Vision

20/200 – 20/400

Profound Low Vision

20/500 – 20/1000

( Near- ) Blindness


20/1250 – 20/2000

Entire Blindness

[ No Light Perception ]

Technology for the Visually Impaired

3.2.1 Basic Technological Needs of the Visually Impaired User

The system must enable comfy control by agencies of combination of address bids and keyboard ( hot key bids ) . Artworks can be used merely in a particular manner as an extra end product for the users that are non wholly blind. Other input/output devices can be used for a specific application provided that such a type of communicating is effectual.

Speech bids should be supported by address ( system driven ) bid lexicon that allows to show a bid in several ways, doing the control of the system more intuitive. This is ever utile, but particularly for blind users where the possibility of intuitive control of the system is even more of import.

Easy customization and constellation is really of import characteristic of the system, particularly for users that frequently use the system for a long clip. This is related to the control commands, manner and type of speech synthesis end product, information informations construction, and other belongingss and options of the system. It is really of import to enable the user to obtain the information rapidly and to let them to acquire an informational overview.

As pointed out, one of the most of import jobs we meet when planing applications for visually impaired users is how to convey a assortment of pieces of information ( some of them can take fundamentally graphical signifier ) rapidly and how to provide sufficient information supplying full orientation of the user. The chief manner to pull off this is to utilize sound. It can be done in the signifier of synthesized voice produced by the syllable based address synthesist. This type of sound end product can be used for bring forthing end product messages and reading text informations. The used address synthesist should concatenate recorded address from a database clearly to heighten quality of the address end product and to separate assorted words. It should be besides able to utilize assorted voice types that can be configured by the user. Assorted voice types can be used to separate assorted types of information.

3.2.2 Specific Demands on User Interfaces for the Visually Impaired

In some applications, there is about no difference in utilizing the user interface between sighted and visually impaired user. This is, for illustration, the instance of duologue systems that are accessible via telephone. However, many systems use artworks as an of import end product for information and they largely besides do non presume that the user is visually impaired and hence they ignore specific demands of such users.

Mobile Applications for the Visually Impaired

“ In the United Kingdom, there are presently around 380,000 people who are registered blind, and a farther 2 million people who have sight jobs or are visually impaired. ”[ 14 ]Fig 3.3.1 indicates that smart phone users over the age of 50 comprise a considerable part of the market. “ About 65 % of all people who are visually impaired are aged 50 and older, while this age group comprises about 20 % of the universe ‘s population. With an increasing aged population in many states, more people will be at hazard of age-related ocular damage. ”[ 15 ]Kavcic confirms that people with disablements represent a big portion of the market, and that accessible package design is encouraged by national Torahs[ 16 ]. These figures reinforce the importance of accommodating user interfaces for the visually impaired.

[ Fig 3.3.1, Beginning: The Nielsen Company ]

Next we analyse some of the most popular applications available today on assorted nomadic platforms. Here popularity is measured by the figure of users who have installed and are actively utilizing the application. These figures are available on the Android Market page.

Digit-Eyes is a alone system which depends on the user to publish labels for any point, which can so be read by the smart phone application and communicated back to the user via address. The application is available at a cost of $ 29.99 [ Digit-Eyes, 2008 ] . Digit-Eyes produces a alone ‘barcode ‘ for each person point which can so be stored into a database within the memory card, and subsequently decoded by the application utilizing a simple barcode scanner. The square barcode form is able to interpret to a upper limit of 100 characters, or an audio file of length limited by the size of the memory card.

LookTel Money Reader is an iPhone application which, through usage of an optical acknowledgment system, is able to recognize US currency and communicate this dorsum to the user through audio [ LookTel, 2010 ] . The system depends on the iPhone ‘s high declaration camera for its service. Perversely to Digit-Eyes, LookTel is unable to work in concurrence with aA­n already available stock barcode reader, and uses its ain acknowledgment techniques.

A Particular Phone 2.0 [ Muhiddine El Kaissi, 2009 ] puts accent on the simpleness of design and easiness of usage of the application. It claims to hold a low larning curve such that ‘the user can be every bit immature as 2 old ages old ‘ [, 2010 ] . The application, which makes usage of the iPhone ‘s accelerometer to supply an eyes-free dialler service, avoids voice acknowledgment and alternatively employs usage of gestures to run.

Finally we look at specially engineered ocular interfaces.

Talking Dialer

[ Fig 3.3.2 Talking Dialer, Eyes-Free Project ]

The Talking Dialer is a consequence of the Eyes-Free Project, which we will be looking into subsequently. One drawback of this application is that it requires the user to download three other back uping applications. If any of those applications should be unavailable, the application will discontinue to work right. The controls are reasonably straightforward- the user places a finger on the screen where they would wish the ‘5 ‘ key to be and the remainder of the computer keyboard forms itself consequently. Therefore to press the ‘4 key, the user will put their finger on the screen and drag straight to the left, and release. First feelings of the application indicate that it could be slow to utilize with somewhat of a acquisition curve. This is because to dial ‘4 ‘ , the user will intuitively put their finger on the left of the screen, and will so be unable to swipe farther left, accordingly being forced to dial ‘5 ‘ . Other possible defects of the application include the inability to cancel the last figure input. The interface is advanced and with some little versions it could besides be a suited music participant interface. Some user remarks in response to this application were noted. One user responded to the fact that three back uping applications had to be installed foremost, “ this fundamentally means that if you are wholly unsighted, and have bought an Android phone you will either demand to hold the store set up the Eyes-free package for you, something that they may non be able to make while you wait ; or you could hold a friend or household member set it up for you.A I feel that this is unacceptable[ 17 ]. ” Sing usage of the application, “ On effort figure 62 you will hold dialed the figure and thenaˆ¦wait a few millenary for the app to trip the phone ‘s ain dialler to dial the figure for you. ” Three of import points can already be derived here ; one that efficiency of the application needs to be improved, that the interface is non every bit intuitive as hoped, and eventually that necessitating 3rd party applications to be pre-installed is impractical in many instances.

Voice Pad

[ Fig 3.3.3 Voice Pad, Blues Labs ]

Voice Pad is basically a notepad to let the user to do speedy notes by talking to their phone. Voice Pad implements a comparatively new characteristic of Android, address acknowledgment. While the engineering is non yet perfected, in that it does non easy recognize all spoken words, it is fast germinating to go a radical characteristic of all Android applications. Through proving the Voice Pad application it was found that address acknowledgment struggled to place simple words such as ‘cheese, humblebee, fountain ‘ and alternatively returned ‘sees, umbrella, amusing ‘ . This deficiency of truth could possible render the application ineffectual.

We found some general applications designed to do the usage of smartphones easier for the visually impaired, such as through screen magnification. There were besides assorted music participants for the Android platform. However, there were no specific music participant applications dedicated for usage by the visually impaired. Since this was the instance, it was decided that the undertaking would concentrate chiefly on the development of a dedicated user interface for the visually impaired, and this would so be implemented into the music participant application. The application will implement characteristics which have had research and development invested into them.

3.4 User Interfaces

Developers employ several different techniques when bring forthing applications for the visually impaired. It can be gathered that the common end is to bring forth the application in such a mode that it basically becomes ‘eyes-free ‘ . These applications are frequently besides marketed to the general population as utile for usage when drive or at other times when concentration on the screen is an incommodiousness. StartTalking [ AdelaVoice, 2010 ] is an ‘entirely voice controlled ‘ application, and advertised as ‘the safer manner to text message for people on the spell ‘ [, 2010 ] . StartTalking is available on all Android 2.x devices, and uses Google ‘s address acknowledgment service to transport out assorted undertakings. Therefore while being used it does non even necessitate the screen to be on.

From analyzing these applications, it can easy be noticed that the focal point of each prevarications in audile interaction with the visually impaired user. Hence we will next analyze the usage of sound in nomadic phone applications.

3.5 Audio

Focus on sounds is advantageous non merely because it allows the visually impaired user to interact with the smartphone with greater easiness, but besides because the sighted user is able to multitask. This can hold a positive consequence on the safety and clip direction of said user.

3.6 Sounds

Identifying sound does non ask the user to be cognizant of the location of the device. Therefore for visually impaired people, sound is a powerful tool when planing user interfaces.

We can split sounds into the two classs of address and non-speech. Address is implemented through the usage of Text To Speech package ( TTS ) , or voice recording. Below we look at some of the several types of non-speech sounds.

3.6.1 Earcons

An earcon is a “ brief, typical sound used to stand for a specific event. ”[ 18 ]They are most familiar as warning tones in computing machine mistake messages. They are besides used in assorted other state of affairss, e.g. for duologue boxes or for an incoming electronic mail message.

3.6.2 Auditory icons

Auditory icons employ “ metaphorical function ”[ 19 ]to convey actions to the user. For illustration, the user may be notified of a system failure with an attach toing auditory icon which plays the sound of an detonation. Garzonis asserts that as a consequence of trials, “ Auditory icons performed significantly better than earcons in footings of intuitivenessaˆ¦validating our pick of metaphors for the audile icons. ”[ 20 ]

3.6.3 Text to Speech

Eyess Free TTS is a address synthesist, which is written wholly in the Java scheduling linguistic communication [ Willie Walker et al. , 2005 ] . A little nomadic talking clock application was created with Eyes Free TTS. Unfortunately compared to a standalone Java application with Eyes Free TTS, the nomadic application did non give the expected consequences.

[ More needed here on TTS systems ]

3.7 Ocular Features

Although we look at interfaces which requires minimum ocular interaction, applications which are targeted towards sighted users besides incorporate ocular AIDSs through images and icons.

3.8 Cognitive burden

Cognitive burden is the sum of attempt the encephalon is put through whilst following instructions. This is indispensable to take into consideration when developing intuitive interfaces or a complex interface which requires some learning curve. Sweller tells us that “ larning happens best under conditions that are aligned with human cognitive architecture. ”[ 21 ]This tells us that we can advance acquisition, whether it be of an algorithm or mathematics equation, through structuring the larning procedure most efficaciously for human acquisition. This structuring is discovered through a series of experiments. Ultimately this leads us to set up information in a manner that allows the user to efficaciously understand and retrieve it.

3.9 Mobile Operating system handiness

There is adequate range for bettering user interfaces for visually impaired users.

Some possible countries of betterments and innovations are listed below. Nordin recognises current attacks such as voice acknowledgment package and text readers as successful. He besides states that ‘most systems have limited handiness if learning demands for user with ocular damage are considered.[ 22 ]

3.9.1 Graphical User Interface ( GUI ) Manipulation

aˆ? GUIs can be magnified to accommodate the user ‘s ocular ability. This will include magnifying icons and founts in the GUI

aˆ?Dual manner GUIs can be implemented, where it is possible to hold normal manners and exaggerated manner.

3.9.2 Icons

aˆ? Scalable icons which the user can resize harmonizing to their penchant

aˆ? Automatic re-alignment and re-positioning of icons when the size is


3.9.3 Voice Components

aˆ? Voice enabled constituents to construct the application, i.e. the application is voice enabled and has an surrogate or attach toing control system.

aˆ? Implementing a different linguistic communication in screen reading and address acknowledgment.

aˆ? We can hold specialised visuals with incorporate voice map.

3.9.4 Haptic Feedback

aˆ? Using quivers on the French telephone for lifes, warnings and particular events.

3.9.5 Alerts

aˆ? Assorted possibilities here, illustrations may include a periodic proclamation of computing machine position, when the user is inactive for a long period of clip.


During the class of the undertaking, garnering feedback from the user group is peculiarly of import. Four visually impaired engineering users were willing to take part in the survey, as described below. Each was given a HTC Wildfire running Android 2.2 ( Froyo ) , and instructed on its usage. For each application they were requested to prove, each user was given 30 proceedingss to utilize the application before noticing.





Cardinal Visual Acuity




Patient at Moorfields Eye Hospital





Patient at Moorfields Eye Hospital




















IT Consultant


These participants will be referred to notice and give constructive unfavorable judgment.

4.1 User Feedback on Applications

MixZing Player

Participant A: “ Text was hard to read, awkward color strategy ”

Participant B: “ Buttons did n’t ever work every bit intended ”

Participant C: “ By and large awkward to use- assorted screens meant the buttons were invariably traveling around ”

Participant Tocopherol: “ ”

Participant F: “ ”

WinAmp Player

Participant A: “ Ads frequently got in the manner of executing basic operations, which made me link to the cyberspace unnecessarily ”

Participant B: “ Reasonably hard to understand how to utilize ”

Participant C: “ Multitude of unneeded options were highlighted on screen, slightly steep larning curve to utilize. ”

Participant Tocopherol: “ ”

Participant F: “ ”

Talking Dialer

Participant A: “ ”

Participant B: “ ”

Participant C: “ ”

Participant D: “ ”

Participant Tocopherol: “ ”

Participant F: “ ”

Voice Pad

Participant A: “ ”

Participant B: “ ”

Participant C: “ ”

Participant D: “ ”

Participant Tocopherol: “ ”

Participant F: “ ”

5 Design And Implementation

In this subdivision we will be looking at the execution of the music participant application. The application was developed in Eclipse with built in Android SDK. The initial paradigm was a simple music participant application built with Java. It loads mp3 files from the memory card and employs three simple buttons to let the user to play, intermission and skip between paths.

Below is a simple usage instance diagram bespeaking the chief necessary maps of a music participant application.

5.1 Choice of Structure

Since it has been decided to construct a series of paradigms re-evaluating user demands at each phase, the pick of construction is linear-iterative.

5.2 Development Procedure

In development of the application, an iterative method was adopted. Following this system, design, execution and rating were repetitively performed to make the concluding application. Upon each loop, demands were reconsidered, to forestall the undertaking from diverting from the original specification. Each paradigm design was discussed in item with visually impaired engineering users, in concurrence with analysis of the research conducted. Several designs were considered, but the most simplistic of these were opted for, due to a important sentiment that it had greatest easiness of usage.

Initially, a paradigm music participant was built without a trim interface:

This initial design was produced in order to derive an apprehension of how the assorted categories in Android work together, peculiarly the Android MediaPlayer category. The simpleness of design was besides chosen to move as an alternate music participant application for usage when proving the concluding merchandise. This paradigm implements Android.MediaPlayer to lade all mp3 files from the memory card. There are three simple buttons, to play/pause, old path, and following path. Two simple text positions show track name and position of the participant. There is an obvious deficiency of functionality from this participant, but it gives a good foundation for the execution of our proposed characteristics.

5.3 Risk Assessment

Hazard appraisal is necessary to analyze what could specifically travel, leting us to take the relevant safeguards.

Hazard falls into three classs:

Undertaking Risk – where agenda or resources are affected

Hardware unavailable: the Android trial device is non working right or unavailable. To avoid this likely happening, two Android devices were purchased, with same platform and proficient specification ( Sony Ericsson Xperia X10 running Android 2.1 ) .

Requirements alteration: the demands change to such an extent that the undertaking changes wholly. Since an iterative development method was adopted, this hazard has been minimised. Each phase of feedback is prompted by analysis of demands and feedback from the last phase.

Specification holds: specification falls behind agenda. To let for some flexibleness, a stiff timetable has been created, with three hebdomads allocated after undertaking closing for any excess work.

Merchandise Risk – where quality or public presentation of merchandise are affected

Size underestimation: system size exceeds outlook. Since there is a deficiency of old experience in working in nomadic package development, or with Android, this is a likely result. Again, to let some flexibleness, the timetable constructed is reasonably generous with excess clip in the execution stage.

Technology alteration: the underlying engineering is overtaken, rendering the application out-dated and useless. Having conducted research on the Android operating system, it can be said with assurance that this is really improbable to go on in the close hereafter.

Merchandise competition: similar applications from rivals are released before undertaking complete. Looking at the types of applications being released on the Android market on a daily footing, this is comparatively improbable.

Business Risk – where the administration developing the merchandise is affected

5.4 Requirements

Through paradigms and experimentation with the assorted Android services encountered, a set of demands were determined. Again, this set was decided upon after careful deliberation with the survey group.

5.4.1 Functional Requirements

Functional demands of the application:

Collect mp3 files from memory card

Sort files suitably

Control playback of files

Adjustable volume

Adaptable to work on all Android smartphones

5.4.2 Non Functional Requirements

Other than being accessible for visually impaired users, the music participant application should ideally be:

Reliable – plays a assortment of music file formats. Avoids crashing during undertakings.

User friendly – there should non be complications to the user interface ; it should be clean and intuitive.

Efficient – no drawn-out lading times.

Safe to run – No alteration of external files or applications.

5.5 Prototype Design

Planing the system involved unifying four chief constituents:

Music participant with standard characteristics

Eyes-free accessible interface

Audio and physical feedback integrated interface

Speech controlled interface

5.6 Ocular Interface

Following participants ‘ suggestions to implement a button free pilotage system, the finalised design consists of a clean canvas whereon the user is able to execute a pre-programmed set of gestures to run the music participant. Other secondary characteristics of the interface include a little rubric saloon and address button, and an issue button placed in the bottom corner of the screen. In the opposite corner is a nexus to the play list screen, where the user is presented with the list of paths sorted in the mode they have selected. The gesture sensitive canvas is maximised for greatest functionality. Gestures will be permitted anyplace on this canvas. Gesture sensitiveness has been increased to be excess antiphonal to bids. Any gestures will be shown on screen with a arrow to assist the user define way and bid. A imperativeness of the bill of fare button will originate an option vocal bill of fare that is sorted by directory instead than mp3 tickets.

Fig 5.5.1 Application ‘splash screen ‘ instructs the user of the bids matching to each gesture

5.7 Integration of Text to Speech

Here we exercised usage of Android TTS libraries. As antecedently discovered, there are assorted text to speech libraries available. I have chosen here to utilize Google ‘s standard Text to Speech library merely for the fact that it is shipped with all Android phones with Android 2.1 or higher installed, and users will non hold to download a separate library ( .jar file ) to back up the application. Although some of these external text to speech libraries are like an expert crafted, with first-class voice capablenesss, I believe handiness is a cardinal issue here. External libraries may non ever be available to the user to download, and may non be every bit good integrated into all Android applications.

Care has been taken to implement the address map where necessary. Not every bid necessitates being spoken out loud. For illustration, the ‘Next Artist ‘ gesture is pre-programmed into the application and alternatively of talking ‘Next Artist ‘ , the system will merely read out the name of the following creative person.

5.8 Screening the Music Library

The music library can be sorted in a figure of different ways. Mp3 files incorporate several ‘tags ‘ which identify choice pieces of information about the file. For illustration, there can be artist, album and bitrate quality tickets. Most simple music participant applications will utilize a straightforward mp3 file name filter, which selects all mp3 files from the memory card and kinds them by file name. However to give the Giggle participant an border over other participants, and therefore do it user friendly with to the full sighted users excessively, I have decided to implement a ticket structured song chooser. This enables the user to screen their music library by choice standards. This places it on a par with more complex and popular intuitive participants such as the DoubleTwist and PowerAmp participants.

5.8.1 Tag Screening

Where the vocal chooser uses tickets, it implements the TrackSelect category, an interface which provides the basic methods to acquire path and creative person information, skip paths, etc. This has been employed to make a system whereby the user can easy categorize their music library and select paths intuitively. Each mp3 file may or may non incorporate tickets to help sorting. Where tickets are available, at the users command the participant will automatically screen the mp3 files from the memory card in order of creative person, album and alphabetical path name, severally. The system uses ID3 tickets, which are most normally used to place mp3 files.

5.9 Speech Commands

Here a late introduced Android characteristic has been implemented. Google Voice Search is pre-installed on all Android smart phones running 2.2 or subsequently, and can be manually installed on earlier microcode. It has been taken into consideration that non all phones may hold Voice Search installed, therefore the address control system has been implemented individually to the gesture bid system. A pat of the upper right corner will trip the address acknowledgment service, and spoken bids will execute the corresponding action. For illustration, if the user taps the button and says ‘Next Track ‘ , the participant will jump to the following available path. For grounds of battery preservation and to avoid unwanted public presentation of the participant, the acknowledgment service is activated merely when the button is pressed.

Fig 5.9.1 The voice acknowledgment service is activated on a touch of the address button

5.10 Accelerometer control

Again non every phone will be equipped with an accelerometer. This is a battery intensive characteristic but after some consideration was included as a characteristic. The add-on makes this the lone music participant application to include to the full incorporate gesture controls. There presently exist many stand-alone applications which offer gesture control when used in concurrence with music participants, but no music participant applications exist that have this characteristic built in. The controls have been configured such that an upward shingle of the phone will trip voice acknowledgment, and a sideways/forward shingle will jump to the following path.

5.11 Haptic Feedback

This is an experimental characteristic with positive feedback, and has therefore been implemented into the concluding design. The basic construct is to delegate a alone quiver form to every map of the music participant. The user will instinctively larn these forms, and this in bend makes the participant easier to utilize eyes-free.


Testing is a cardinal portion of any development procedure. In this undertaking, the group of participants was requested to utilize the Giggle application in conformity with a counsel sheet. They were so asked to follow the same instructions for the first paradigm application, the MixZing application and remark on their experiences. The counsel sheet can be found in the appendices.

Feedback: Prototype

Transporting out undertakings:


Feedback: MixZing Player

Transporting out undertakings:


Feedback: Giggle Player

Transporting out undertakings:


7 Evaluation

Evaluation of the application was performed continuously throughout the lifecycle. Since we used the iterative development manner, user demands were sporadically re-analysed and the paradigm was evaluated alongside these. Each functional paradigm was ab initio run on the Android SDK copycat to find any digest mistakes. However since the copycat does non assure right functionality, the paradigm was so installed and run on a Sony Ericsson Xperia X10. This allowed accurate testing of the application ‘s maps, since there were frequently instances where the application would run on the copycat but non on the nomadic phone. Reasons for this may include the fact that certain parts of the application such as the accelerometer and voice acknowledgment can non be emulated on the computing machine for obvious grounds. Here we will be looking at whether our demands, both functional and non-functional, have been met.

Further Developments

Since the application basically combines two constituents ( an accessible interface with a to the full functional music participant ) , each constituent can be separately improved. With more clip available, some betterments could hold been made to heighten the application farther. To appeal to a greater user market, the application should, in footings of functionality, be on par with the priced applications in the Android Market. Therefore some possible betterments are:

Include album graphics, if unavailable so download from cyberspace

Detect and download path information from cyberspace

Equaliser scenes to set music harmonizing to penchant ( e.g. Rock, Classical etc. )

Ability to put track as ringtone

These must be implemented whilst keeping the accessible interface. With regard to the interface, the undermentioned betterments could be implemented.

Greater voice control of the application, e.g. the ability to open the application by talking its name.

Adaptability with all Android French telephone keyboards

Transferability. It is hope the application will be translated for usage onto iPhone and Nokia smart phones.

Adjustable coloring material strategies

Android is a comparatively new runing system, and as we have seen, it is fast going the most popular nomadic platform. Therefore as more developers work with Android, new and advanced characteristics will be progressively available. These will hopefully lend to the visually impaired experience of smart phones.


Age: __________

Gender: M F

Occupation: _______________________________________________________________

Are you a smart phone user? If yes, please province brand and theoretical account.


What features of the phone make it easy to utilize for you?


Put the followers in order of how valuable the undermentioned characteristics are to you when utilizing a nomadic phone, from 1 ( least of import ) to 8 ( most of import )

Voice acknowledgment _______

Text to Speech _______

Gesture controlled operation _______

Movement controlled operation _______

Adjustable font size _______

Adjustable coloring material strategy _______

Compatibility with external controls e.g. a Bluetooth headset _______

Intuitive interface with short larning curve _______

Extra Remarks


Testing the Application

Find and open the application

Play path

Skip to following path

Skip to the path named ‘Explosions in The Sky – The First Day ‘

Fast frontward to 1:30

Skip to next album

Skip to following creative person

Adjust volume

Return to place screen, lock, unlock and return to application

Exit application

Extra Remarks