Human Voices

_{Last updated: April 7, 2026 | 2 minutes read}

UIKit

This example demonstrates how to use GEMKit in a UIKit application to download and use human-recorded voice packages for turn-by-turn navigation guidance via HumanVoiceContext.

Check the full implementation on GitHub.

Intial screen with Voices and Route buttons

Voices List

UI and Map Integration

A dedicated Voices button navigates to a list screen for browsing and downloading voice packages. A SoundContext activates the selected voice before simulation:

ViewController.swiftView on GitHub

class ViewController: UIViewController, MapViewControllerDelegate, NavigationContextDelegate {

    var mapViewController: MapViewController?
    var navigationContext: NavigationContext?
    var soundContext: SoundContext?

    override func viewDidLoad() {

        super.viewDidLoad()

        self.createMapView()
        self.mapViewController!.startRender()

        self.addVoicesButton()
        self.addRouteButton()
    }

    func addVoicesButton() {

        let barButton = UIBarButtonItem.init(title: "Voices", style: .done, target: self, action: #selector(voicesList))

        self.navigationItem.leftBarButtonItems = [barButton]
    }

    @objc func voicesList() {

        let viewController = VoicesViewController.init()
        self.navigationController?.pushViewController(viewController, animated: true)
    }

Browsing and Downloading Voice Packages

VoicesViewController uses HumanVoiceContext to fetch both the locally installed list and the online catalogue. Each row shows a country flag and download progress bar. Tapping a row starts or pauses the download:

VoicesViewController.swiftView on GitHub

class VoicesViewController: UITableViewController, ContentStoreObjectDelegate {

    var humanVoiceContext: HumanVoiceContext?
    var contentStoreList: [ContentStoreObject] = []

    override func viewDidLoad() {

        super.viewDidLoad()

        self.humanVoiceContext = HumanVoiceContext.init()

        self.refreshWithLocal()
        self.refreshWithOnline()
    }

    func refreshWithOnline() {

        self.humanVoiceContext!
            .getOnlineList { [weak self] array in

                guard let weakSelf = self else { return }

                if !array.isEmpty {
                    weakSelf.contentStoreList = array
                    weakSelf.tableView.reloadData()
                }
            }
    }

    func refreshWithLocal() {

        self.contentStoreList = self.humanVoiceContext!.getLocalList()
    }

Activating a Human Voice for Navigation

When a row with a completed download is tapped, the voice package identifier is passed to setUseHumanVoiceWithIdentifier(_:completionHandler:) on the root view controller's SoundContext, then the screen is dismissed:

VoicesViewController.swiftView on GitHub

        } else if status == .completed {

            if let rootViewController = self.navigationController?.viewControllers.first as? ViewController {

                if let soundContext = rootViewController.soundContext {

                    soundContext.setUseHumanVoiceWithIdentifier(object.getIdentifier()) { success in }
                }

                self.navigationController?.popViewController(animated: true)
            }
        }