import { HttpClient, HttpResponse } from '@angular/common/http';
import { Observable } from 'rxjs';
export declare class ServerPayload {
    nonce: string;
    captcha: string;
    validation: string;
    expiry: string;
}
export declare class CaptchaDataService {
    private httpClient;
    constructor(httpClient: HttpClient);
    fetchData(apiBaseUrl: string, nonce: string): Observable<HttpResponse<ServerPayload>>;
    verifyCaptcha(apiBaseUrl: string, nonce: string, answer: string, encryptedAnswer: string): Observable<HttpResponse<ServerPayload>>;
    fetchAudio(apiBaseUrl: string, validation: string, translation?: string): Observable<HttpResponse<string>>;
}