export interface MicrophoneRequest {
    deviceId: string | undefined;
}
export declare function isSameMicrophoneRequest(request: MicrophoneRequest | null, deviceId: string | undefined): boolean;
export type MicrophoneAcquireResult = {
    status: "ready";
    stream: MediaStream;
    source: "selected" | "fallback";
} | {
    status: "failed";
    primaryError: unknown;
    fallbackError: unknown;
} | {
    status: "stale";
};
/**
 * One selected-device attempt plus its fallback, tied to one request identity.
 * A superseded request may still settle, but it may not publish or start a fallback.
 */
export declare function acquireMicrophoneForRequest(request: MicrophoneRequest, currentRequest: () => MicrophoneRequest | null, getMicrophone: (deviceId?: string) => Promise<MediaStream>, onPrimaryFailure?: (error: unknown) => void): Promise<MicrophoneAcquireResult>;