export type FrequencyRange = [number, number];
export declare function is(value: number, range: FrequencyRange): boolean;
export declare function isNot(value: number, range: FrequencyRange): boolean;
/**
 * Average 2 half periods for better precision
 */
export declare function avg(value1: number | undefined, value2: number | undefined): number | undefined;
export declare function oscillationIs(firstHalfValue: number | undefined, secondHalfValue: number | undefined, range: FrequencyRange): boolean | undefined;
export declare function bitByFrequency(value: number | undefined, rangeZero: FrequencyRange, rangeOne: FrequencyRange): boolean | undefined;