How can i detect one word with speech recognition

I know how to detect speech with Python but this question is more specific: How can I make Python listening for only one word and then returns True if Python could recognize the word.

I know, I could just let Python listen all the Time and then make something like that Pseudocode:

while True:
    if stt.listen() == "keyword":
        return True

I have already made that and the program is hanging up after some minutes of always listening (See at the end). So I need a way to only listen for one specific word.

What does "hang up" mean? The program is not crashing but not responding. It isn't listening to my voice anymore and when I press STRG + C it does nothing.

I am searching for something like this:

while True:
    if stt.waitFor("keyword"):
        return True

Hope you understood, Best regards

import sys, os
from pocketsphinx.pocketsphinx import *
from sphinxbase.sphinxbase import *
import pyaudio

modeldir = "../../../model"
datadir = "../../../test/data"

# Create a decoder with certain model
config = Decoder.default_config()
config.set_string('-hmm', os.path.join(modeldir, 'en-us/en-us'))
config.set_string('-dict', os.path.join(modeldir, 'en-us/cmudict-en-us.dict'))
config.set_string('-keyphrase', 'forward')
config.set_float('-kws_threshold', 1e+20)


p = pyaudio.PyAudio()
stream = p.open(format=pyaudio.paInt16, channels=1, rate=16000, input=True, frames_per_buffer=1024)
stream.start_stream()

# Process audio chunk by chunk. On keyword detected perform action and restart search
decoder = Decoder(config)
decoder.start_utt()
while True:
    buf = stream.read(1024)
    if buf:
         decoder.process_raw(buf, False, False)
    else:
         break
    if decoder.hyp() != None:
        print ([(seg.word, seg.prob, seg.start_frame, seg.end_frame) for seg in decoder.seg()])
        print ("Detected keyword, restarting search")
        decoder.end_utt()
        decoder.start_utt()

For more details see http://cmusphinx.sourceforge.net