import { PassThrough } from "stream";
import { IsSilence } from "./IsSilence.js";
import type { MicOptions } from "./MicOptions.js";
export declare abstract class Mic {
    /**
     * This instantiates the process arecord OR sox using the options specified
     */
    abstract start(): void;
    /**
     * This kills the arecord OR sox process that was started in the start() routine. It uses the SIGTERM signal.
     */
    abstract stop(): void;
    /**
     * This pauses the arecord OR sox process using the SIGSTOP signal.
     */
    abstract pause(): void;
    /**
     * This resumes the arecord OR sox process using the SIGCONT signal.
     */
    abstract resume(): void;
    /**
     * This returns a simple Transform stream that contains the data from the arecord OR sox process. This sream can be directly piped to a speaker sream OR a file stream. Further this provides a number of events triggered by the state of the stream:
     * - `silence`: This is emitted once when exitOnSilence number of consecutive frames of silence are found.
     * - `sound`: This is emitted if we hear something after a silence.
     * - `processExitComplete`: This is emitted once the arecord OR sox process exits.
     * - `startComplete`: This is emitted once the `start()` function is successfully executed.
     * - `stopComplete`: This is emitted once the `stop()` function is successfully executed.
     * - `pauseComplete`: This is emitted once the `pause()` function is successfully executed.
     * - `resumeComplete`: This is emitted once the `resume()` function is successfully executed.
     * - It further inherits all the Events from `Transform`.
     */
    abstract getAudioStream(): PassThrough;
}
export declare class MicImpl implements Mic {
    private audioProcess;
    private infoStream;
    private audioStream;
    private debug;
    private arecordEncoding;
    private arecordEndian;
    private bitwidth;
    private arecordFormat;
    private endian;
    private channels;
    private rate;
    private encoding;
    private fileType;
    private device;
    constructor(options?: MicOptions);
    private getAudioProcessOptions;
    start(): void;
    stop(): void;
    pause(): void;
    resume(): void;
    getAudioStream(): IsSilence;
}