How to improve EventEmitter event notification function？

I wrote the following EventEmitter class, and it works great so far. But today I came across a scenario where if event listeners are created and destroyed frequently, and the off function is not used to remove the listener, there will be potential performance issues. How can I optimize this problem? Can anyone give me some ideas?

class EventEmitter {

    private listeners: Record<string, [Set<Function>, Set<Function>]> = {};

    existsEvent(eventName: string | number) {
        return !!this.listeners[eventName];
    }

    on(eventName: string | number, listener: Function) {
        if (!this.listeners[eventName]) {
            this.listeners[eventName] = [new Set(), new Set()];
        }
        this.listeners[eventName][0].add(listener);
    }

    once(eventName: string | number, listener: Function) {
        if (!this.listeners[eventName]) {
            this.listeners[eventName] = [new Set(), new Set()];
        }
        this.listeners[eventName][1].add(listener);
    }

    emit(eventName: string | number, ...args: any[]) {
        if (!this.listeners[eventName]) {
            return
        }

        this.listeners[eventName][0].forEach((listener: Function) => {
            listener(...args);
        });
        
        this.listeners[eventName][1].forEach((listener: Function) => {
            listener(...args);
        });
        this.listeners[eventName][1].clear();
    }

    off(eventName: string | number, listener: Function) {
        if (!this.listeners[eventName]) {
            return;
        }
        if (typeof listener === 'function') {
            this.listeners[eventName][0].delete(listener);
            this.listeners[eventName][1].delete(listener);
        } else {
            this.listeners[eventName][0].clear();
            this.listeners[eventName][1].clear();
        }
    }
}

export const eventEmitter = new EventEmitter();