import type { ExistingProvider, Type } from '@angular/core';
import { InjectionToken } from '@angular/core';
export declare const WA_AUDIO_NODE: InjectionToken<AudioNode | null>;
export declare function asAudioNode(useExisting: Type<AudioNode>): ExistingProvider;
/**
 * @deprecated: drop in v5.0, use {@link WA_AUDIO_NODE}
 */
export declare const AUDIO_NODE: InjectionToken<AudioNode | null>;