/// <reference types="node" />
/**
 * Implementing class generates stream of DTMF encoded in an 8 bit PCM encoding (MULAW) at 8000 Hertz
 */
export interface DtmfBufferGenerator {
    /**
     * @param dtmfSequence - Supported digits are 0123456789*# and w. w represents a pause of 0.5s.
     */
    generate(dtmfSequence: string): Buffer;
}