Kivy Won't Update Label While Reading from Microphone Using PyAudio

Question

I am trying to update a Label in Kivy to say when the program is recording audio. I am having a problem where the PyAudio part takes over the thread and the text sent just before the record to the label doesn't update.

Update: the text "Recording..." is not appearing on the label.

Here is my code (that doesn't update):

self.answer.text = "Recording..." 
lib.record.record_audio()
self.answer.text = "Converting to text..."

And then I am using the standard PyAudio for recording:

import pyaudio
import wave

def record_audio():
    CHUNK = 1024
    FORMAT = pyaudio.paInt16
    CHANNELS = 1
    RATE = 44100
    RECORD_SECONDS = 5
    WAVE_OUTPUT_FILENAME = "output.wav"

    p = pyaudio.PyAudio()

    stream = p.open(format=FORMAT,
                    channels=CHANNELS,
                    rate=RATE,
                    input=True,
                    frames_per_buffer=CHUNK)

    print("* recording")

    frames = []

    for i in range(0, int(RATE / CHUNK * RECORD_SECONDS)):
        data = stream.read(CHUNK)
        frames.append(data)

    print("* done recording")

    stream.stop_stream()
    stream.close()
    p.terminate()

    wf = wave.open(WAVE_OUTPUT_FILENAME, 'wb')
    wf.setnchannels(CHANNELS)
    wf.setsampwidth(p.get_sample_size(FORMAT))
    wf.setframerate(RATE)
    wf.writeframes(b''.join(frames))
    wf.close()

Thanks

Update: Including full class call

The function in question:

def record_clicked(self, btn):
    self.answer.text = "Recording..."    #Doesn't display
    # uncomment the below line to input a new wave file 
    lib.record.record_audio()    #Takes 5 seconds
    self.answer.text = "Converting to text..."    #Doesn't display
    analyzed_tuple = lib.record.analyze_audio()   #Takes around ten seconds
    self.answer.text = analyzed_tuple[1]    #Displays
    self.search.text = analyzed_tuple[0]

Where it is called:

    record_button = Button(text="Rec.", size_hint=(0.15, 1))
    record_button.bind(on_press=self.record_clicked)
    top_layout.add_widget(record_button)