diff --git a/alsaaudio.c b/alsaaudio.c
index 17c3b98..ea0ff4e 100644
--- a/alsaaudio.c
+++ b/alsaaudio.c
@@ -423,11 +423,16 @@ alsapcm_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
     char *card = NULL;
     int cardidx = -1;
     char hw_device[128];
-    char *kw[] = { "type", "mode", "device", "cardindex", "card", NULL };
+    int rate = 44100;
+    int channels = 2;
+    int format = SND_PCM_FORMAT_S16_LE;
+    int periodsize = 32;
 
-    if (!PyArg_ParseTupleAndKeywords(args, kwds, "|Oisiz", kw,
+    char *kw[] = { "type", "mode", "device", "cardindex", "card", "rate", "channels", "format", "periodsize", NULL };
+
+    if (!PyArg_ParseTupleAndKeywords(args, kwds, "|Oisiziiii", kw,
                                      &pcmtypeobj, &pcmmode, &device,
-                                     &cardidx, &card))
+                                     &cardidx, &card, &rate, &channels, &format, &periodsize))
         return NULL;
 
     if (cardidx >= 0) {
@@ -471,10 +476,10 @@ alsapcm_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
     self->handle = 0;
     self->pcmtype = pcmtype;
     self->pcmmode = pcmmode;
-    self->channels = 2;
-    self->rate = 44100;
-    self->format = SND_PCM_FORMAT_S16_LE;
-    self->periodsize = 32;
+    self->channels = channels;
+    self->rate = rate;
+    self->format = format;
+    self->periodsize = periodsize;
 
     res = snd_pcm_open(&(self->handle), device, self->pcmtype,
                        self->pcmmode);
diff --git a/doc/libalsaaudio.rst b/doc/libalsaaudio.rst
index dc4527b..b4f1277 100644
--- a/doc/libalsaaudio.rst
+++ b/doc/libalsaaudio.rst
@@ -108,7 +108,7 @@ PCM objects in :mod:`alsaaudio` can play or capture (record) PCM
 sound through speakers or a microphone. The PCM constructor takes the
 following arguments:
 
-.. class:: PCM(type=PCM_PLAYBACK, mode=PCM_NORMAL, device='default', cardindex=-1)
+.. class:: PCM(type=PCM_PLAYBACK, mode=PCM_NORMAL, rate=44100, channels=2, format=PCM_FORMAT_S16_LE, periodsize=32, device='default', cardindex=-1)
 
    This class is used to represent a PCM device (either for playback and
    recording). The arguments are:
@@ -117,6 +117,10 @@ following arguments:
      (default).  
    * *mode* - can be either :const:`PCM_NONBLOCK`, or :const:`PCM_NORMAL`
      (default). 
+   * *rate* - the sampling rate. The default value is 44100.
+   * *channels* - the number of channels. The default value is 2 (stereo).
+   * *format* - the data format. The default value is :const:`PCM_FORMAT_S16_LE`,
+   * *periodsize - the period size. The default value is 32. Each write should consist of *periodsize* frames.
    * *device* - the name of the PCM device that should be used (for example
      a value from the output of :func:`pcms`). The default value is
      ``'default'``.
@@ -125,12 +129,11 @@ following arguments:
      the `device` keyword argument is ignored.
      ``0`` is the first hardware sound card.
 
-   This will construct a PCM object with these default settings:
+   This will construct a PCM object with the given settings.
 
-   * Sample format: :const:`PCM_FORMAT_S16_LE`
-   * Rate: 44100 Hz 
-   * Channels: 2
-   * Period size: 32 frames
+   *Changed in 0.9:*
+
+   - Added optional arguments `rate`, `channels`, `format` and `periodsize`.
 
    *Changed in 0.8:*