About the study

Like living things, languages evolve. Recall how your grandparents speak: their words and expressions are not quite yours. Language changes across generations and within a lifetime. Why? Because we don’t just inherit language from our parents. We pick up words from friends, neighbours, teachers, songs and screens, and pass them on, slightly changed, to the people we talk to. Since no two people have exactly the same network, each of us has a unique speech fingerprint. Now imagine comparing the speech of thousands or millions of people. Together, these voices could reveal how languages change through chance, innovation, preferences and mixing, as well as the inherent limits of human language – perhaps even offering a glimpse of our future language pool.

Do we speak more like our parents or our friends? Where does one language end and another begin? When very different languages meet, what do they borrow from each other? How did we come to speak more than 7,000 languages worldwide? LECT (Language Evolution Collective), a citizen science project by researchers from the University of Zurich (UZH), invites you to help find the answers. Your voice is a piece of the puzzle.

Who can take part

You can take part if you are 15 or older and live in a country where this study has been approved (listed in the app).

Depending on your age and the laws of your country, we may need consent from a legal guardian. If so, we will tell you during registration and you can send them a request through the app. Your guardian then needs to create their own LECT account and complete the profile before they can review this information and consent. Once they consent, you and your guardian will be linked as a connection. Taking part remains your choice, and either of you may withdraw at any time.

What you will do

To take part, you need to create an account with your phone number or email address and set up a profile. After that, you choose what to do, and how much:

• Do language tasks, such as watching short videos and narrating them out loud as you watch, or naming objects or actions shown in pictures, in any language you speak fluently.
• Tell us about your family: where your parents and grandparents come from and which languages they speak.
• Complete short surveys about language use and mobility, or tell us about your research interests. Your answers may shape what we explore next.
• Connect with others: invite family, friends and other people you talk with to join LECT and link your profiles.
• Learn and explore: discover how languages, cultures and genes evolve, and follow our projects and findings.

You can contribute whenever you like, in as many sessions as you like. Some profile and survey questions are optional, and you can skip them if you prefer not to answer. Every contribution helps: the more you share, the more questions we can answer. Family details and linked profiles, for example, show how language is passed on across generations and reveal who we speak most like.

If you do not have your own phone or email address, you can share an account with others in the same country, such as household members. Each person consents separately, but everyone on the account may see each other’s profiles, and app messages go to the account’s phone number or email.

If changes to the study or new information may affect your decision to take part, or if there is a related study you may wish to join, we will contact you by SMS or email. We may also send you up to three reminders to repeat a recording, at most one per month, because repeating a recording makes our results more reliable.

Who is responsible

The University of Zurich is responsible for your data (data controller) and handles it in line with Swiss data protection law and the law of the country where you live. Research contact: Prof. Sandra Oliveira, Department of Evolutionary Biology and Environmental Studies, Winterthurerstrasse 190, 8057 Zurich, Switzerland, sandra.dasilvaoliveira@uzh.ch.

What we collect

We collect the information listed below:

• Phone number or email address: identifies your account and receives the one-time code used to sign in.
• Password: stored only in encrypted form (as a cryptographic hash), never readable.
• Personal details: name, age, country, place of birth, residence, past residences (optional), gender (optional), the languages you speak and with whom or where you speak them.
• Residence: depending on the country, a postal code or village/city will be requested. In some countries, you can choose to share your GPS location once, to help us identify the nearest village.
• Family background (optional): your parents’ and grandparents’ hometowns and the languages they speak.
• Survey answers (optional): your responses and when you gave them. Surveys are country-specific. Where relevant, we may ask for sensitive information, such as your and your family’s ethnic group and clan. This data is protected and kept private (see below). If you are offline, they are kept on your device until they can be uploaded, and are then deleted from it.
• Audio recordings (optional): recordings you make with the microphone during a task. If you are offline, they are kept on your device until they can be uploaded, and are then deleted from it.
• Your connections: if you invite someone or accept an invitation, we store the link between your accounts and how you are related, which you select from a list (for example, “mother” or “friend”). Your selection is not shown to other users.
• The name and phone number or email of people who were invited but haven't joined yet.
• Participation progress: the number of tasks you completed and whether they passed our quality check, stored as points that unlock features in the app.
• Technical data: information needed for secure sign-in and for running the app (e.g. sign-in times, technical error logs, technical recording information such as microphone settings). These are not used for research.

The app contains no advertising, no analytics and no tracking of any kind. It does not access your contacts or photos, and uses the microphone only while you are recording.

Why we collect it

We use your information to carry out linguistic research, run your account and keep the app secure, send invitations on your behalf, count your points and unlock app features, show you results, and inform you about changes to the study and related studies.

We process your data on the basis of your consent, which you give at the end of this page. We never sell your data or use it for commercial purposes.

Who sees it

• Our research team at the University of Zurich (Prof. Oliveira’s group) and approved research partners and app developers, all bound by confidentiality agreements.
• The cloud service provider operating the app, SWITCH, which stores all data on servers in Switzerland. If we move to another provider, the same level of data protection will apply.
• Twilio, which sends our SMS or email messages, receives only the phone number or email address needed for this. Twilio processes and stores this data in Ireland (EU). Messages are then delivered through the recipient’s mobile network operator or email provider.

When you invite someone, the invitation shows only your name and your phone number or email address, so they know who it is from. Other researchers may request and receive some of your de-identified data under strict conditions (see “Sharing data for future research”).

Where your data is stored

Your data is stored in Switzerland. If you live in another country, this means your data leaves your country. Switzerland has strong data protection laws, and we ask for your explicit agreement to this transfer at the end of this page.

How your data is protected

All data is encrypted when sent between the app and our servers, and when stored with our cloud service provider. App data is regularly transferred to secure UZH servers, accessible only to authorised members of the research team.

To protect your privacy, we analyse de-identified data. This means we remove details that could identify you (your name, email address and phone number) and use only a study code. GPS location and postal code, when available, are replaced by the nearest village or town, and recordings are converted into text, so your voice is not shared. Survey answers about your research interests are separated from your other data and pooled with the answers of many other participants for analysis and reporting.

Backup copies of the raw data you originally provided (except GPS location) are stored securely at UZH.

We take all reasonable measures to protect your data, but no system can be completely secure. In the unlikely event that your data is accessed without permission and this may affect you, we will inform you and the relevant authorities.

How long we keep it

• All data on the app hosting server: until the app is discontinued or you withdraw from the study.
• Contact details of people you invite: deleted after 30 days if they do not accept.
• De-identified data on UZH servers: kept as a working copy and deleted when the project ends or if you withdraw.
• De-identified data in a controlled-access repository: kept for unlimited time or until you withdraw.
• Backup of the raw data: stored for unlimited time to allow replication of results with improved analysis (for example, improved speech-to-text transcription), unless you withdraw.

Sharing data for future research

Your de-identified data may be shared with other researchers in Switzerland or abroad through a controlled-access repository, for non-commercial research only. Each request must be approved by a Data Access Committee (including this project’s investigators), and researchers must sign an agreement forbidding any attempt to re-identify you. To reduce risks, profile connections are included only when needed for a particular project, and only as linked study codes.

Sharing allows researchers to check our analyses and answer other questions relating to language evolution. No one involved will profit from sharing the data.

Inviting others

You can invite others to join and link profiles with you by sharing your personal code or by entering their phone number or email. Please ask their permission before sharing their contact details. They decide freely whether to take part and link their profile to yours. Linked users cannot see each other’s answers or recordings.

Results and app features

The main findings of this study will be reported in the app after they are reviewed by experts and will be available to all users. They will also appear in scientific journals and be presented to the public. Results describe groups, and no one can be identified.

Additionally, the app counts the tasks you complete that pass our quality check (for example, that recordings are audible), and you collect points. These points unlock additional personal features such as how similar your way of speaking is to that of people linked to you, personalised language maps and graphics. Only you can see them. They become available once enough data has been collected and analysed for your language and connections. Because the amount of data needed varies between languages, these features may not be available to everyone.

Risks and benefits

Your data could be accessed by someone without permission. This risk is small, but your voice recordings in particular could identify you, so we protect it with extra care (see “How your data is protected”).

Your participation helps build a record of the world’s languages for future generations and show how languages change. You may also enjoy exploring your personal results, though we cannot promise any direct benefit to you.

Participation through the app alone is unpaid. If you take part in one of our field studies, our team guides you in a more controlled setting; any compensation for this is explained in that study’s consent form, which takes precedence.

Withdrawing your consent

Taking part is voluntary. You can withdraw your consent at any time, without giving a reason and without any disadvantage. Open your profile in the app and choose “Withdraw consent and delete profile”, or contact us (sandra.dasilvaoliveira@uzh.ch). We will then delete your data, including backups, and remove it from the research repository so it is not used or shared for new research. Some uses cannot be undone:

• results already published or shared;
• analyses well under way;
• de-identified data already shared with other researchers;
• computer models already trained with your data. These do not store your recordings or personal details and cannot identify you.

Withdraw consent and delete profile

Your rights

You can ask to see what we hold about you, receive a copy, or have it corrected or deleted. You can also object to its use. You do not need to give a reason, and there is no disadvantage. We reply within 30 days.

For concerns about your data, contact the UZH data protection office (privacy@rud.uzh.ch). You can also complain to the data protection authority in your country.

Ethics approval

This study was approved by the Ethics Committee of the Faculty of Arts and Social Sciences, University of Zurich, and, where required, by the relevant ethics committees or authorities in each participating country.