diff --git a/pydub/audio_segment.py b/pydub/audio_segment.py
index 88ffec53..aec0cc1c 100644
--- a/pydub/audio_segment.py
+++ b/pydub/audio_segment.py
@@ -7,7 +7,7 @@
 import wave
 import sys
 import struct
-from .logging_utils import log_conversion
+from .logging_utils import log_conversion, log_subprocess_output
 import base64
 
 try:
@@ -511,6 +511,9 @@ def is_format(f):
         p = subprocess.Popen(conversion_command, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
         p_out, p_err = p.communicate()
 
+        log_subprocess_output(p_out)
+        log_subprocess_output(p_err)
+
         if p.returncode != 0:
             raise CouldntDecodeError("Decoding failed. ffmpeg returned error code: {0}\n\nOutput from ffmpeg/avlib:\n\n{1}".format(p.returncode, p_err))
 
@@ -674,6 +677,9 @@ def export(self, out_f=None, format='mp3', codec=None, bitrate=None, parameters=
         p = subprocess.Popen(conversion_command, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
         p_out, p_err = p.communicate()
 
+        log_subprocess_output(p_out)
+        log_subprocess_output(p_err)
+
         if p.returncode != 0:
             raise CouldntEncodeError("Encoding failed. ffmpeg/avlib returned error code: {0}\n\nCommand:{1}\n\nOutput from ffmpeg/avlib:\n\n{2}".format(p.returncode, conversion_command, p_err))
 
diff --git a/pydub/logging_utils.py b/pydub/logging_utils.py
index af239753..a312bd24 100644
--- a/pydub/logging_utils.py
+++ b/pydub/logging_utils.py
@@ -6,4 +6,9 @@
 converter_logger = logging.getLogger("pydub.converter")
 
 def log_conversion(conversion_command):
-    converter_logger.debug("subprocess.call(%s)", repr(conversion_command))
\ No newline at end of file
+    converter_logger.debug("subprocess.call(%s)", repr(conversion_command))
+
+def log_subprocess_output(output):
+    if output:
+        for line in output.rstrip().splitlines():
+            converter_logger.debug('subprocess output: %s', line.rstrip())