Apparently 60ms is too much for some cards.

---
 src/libespeak-ng/speech.c |    2 +-
 tests/klatt.test          |   10 +++++-----
 tests/variants.test       |    2 +-
 3 files changed, 7 insertions(+), 7 deletions(-)

--- a/src/libespeak-ng/speech.c
+++ b/src/libespeak-ng/speech.c
@@ -80,7 +80,7 @@ static void *my_user_data = NULL;
 static espeak_ng_OUTPUT_MODE my_mode = ENOUTPUT_MODE_SYNCHRONOUS;
 static int out_samplerate = 0;
 static int voice_samplerate = 22050;
-static const int min_buffer_length = 60; // minimum buffer length in ms
+static const int min_buffer_length = 49; // minimum buffer length in ms
 static espeak_ng_STATUS err = ENS_OK;
 
 static t_espeak_callback *synth_callback = NULL;
--- a/tests/klatt.test
+++ b/tests/klatt.test
@@ -4,8 +4,8 @@
 # and run needed checks before
 is_hash
 # call actual test functions
-test_wav en+klatt  "8155a2249db8f6fe5f3b1d4fd00c35d09ceb6c82" "The quick brown fox jumps over the lazy dog"
-test_wav en+klatt2 "90559a2ff9973c3ccf1eb7e71579fedfedbd3c67" "The quick brown fox jumps over the lazy dog"
-test_wav en+klatt3 "a636bc97d68fbec753c7cecc718b539c87627095" "The quick brown fox jumps over the lazy dog"
-test_wav en+klatt4 "653e243019c9462c7a9a90f4b03326d45b45f41c" "The quick brown fox jumps over the lazy dog"
-test_wav en+klatt5 "6665329b413244b9846533ce207f0ee3d6e55094" "The quick brown fox jumps over the lazy dog"
+test_wav en+klatt  "19f85968f7364b418bdcad477a90070e5d08c85e" "The quick brown fox jumps over the lazy dog"
+test_wav en+klatt2 "359d75dc42ca8342008fe48d99116f15bc8a761a" "The quick brown fox jumps over the lazy dog"
+test_wav en+klatt3 "72db6bbc6436ad76cee250038f504d6ce43c8008" "The quick brown fox jumps over the lazy dog"
+test_wav en+klatt4 "766cfac20f083615448809c68d1e530401960ab6" "The quick brown fox jumps over the lazy dog"
+test_wav en+klatt5 "396de0cf0d09b8ab311ab572e8ad5096c0bc1d6d" "The quick brown fox jumps over the lazy dog"
--- a/tests/variants.test
+++ b/tests/variants.test
@@ -10,4 +10,4 @@ test_wav "en+nonexisting" 029983e9084e04
 test_wav "en+f1" dba359ac75ec33cc9cd4bd2af5031a3dbd84427c "Testing variants"
 test_wav "en+anikaRobot" d56012d8f4cfb4c36fdad31ad9ad7abda40ef474 "Testing variants"
 test_wav "en+Demonic" cc24431d23ce6d0a36f6a46df374f995beeb2863 "Testing variants"
-test_wav "en+klatt4" e03e3c6204de48d3e5b172cca4cca1ff09461ee1 "Testing variants"
+test_wav "en+klatt4" 5dac8221860dbb6ec8534923a208787bdb2960ce "Testing variants"
