signals.py

from PyQt5 import QtWidgets, QtCore, QtGui
from PyQt5.QtCore import Qt

class Speaker(QtCore.QObject):
    speak = QtCore.pyqtSignal(int)

class Listener(QtCore.QObject):
    def onSpeech(self, value):
        print(value)

if __name__ == "__main__":

    app = QtWidgets.QApplication([])

    speaker1 = Speaker()
    speaker2 = Speaker()

    listener = Listener()

    speaker1.speak.connect(listener.onSpeech)

    speaker1.speak.emit(1) # будет услышано лиснером
    speaker2.speak.emit(2) # не будет услышано лиснером

    print(speaker1.speak is speaker2.speak) # чомуто False

    app.exec()