fix example

src/main/iltcdf.cc

@@ -81,6 +81,14 @@ void PrintUsage(std::ostream* stream) {
  * - @b stdout
  *   - double-type output sequence
  *
+ * In the below example, an excitaion signal generated from pitch information is
+ * reconstructed using the synthesis and analysis filters built from PARCOR
+ * coefficients.
+ *
+ * @code{.sh}
+ *   excite < data.pitch | ltcdf data.rc | iltcdf data.rc > data.e
+ * @endcode
+ *
  * @param[in] argc Number of arguments.
  * @param[in] argv Argument vector.
  * @return 0 on success, 1 on failure.

src/main/lspdf.cc

@@ -90,8 +90,8 @@ void PrintUsage(std::ostream* stream) {
  * - @b stdout
  *   - double-type output sequence
  *
- * In the below example, an exciation signal generated from pitch information is
- * passed through the synthesis filter built from LSP coefficients.
+ * In the below example, an excitation signal generated from pitch information
+ * is passed through the synthesis filter built from LSP coefficients.
  *
  * @code{.sh}
  *   excite < data.pitch | lspdf data.lsp > data.syn

src/main/ltcdf.cc

@@ -81,8 +81,8 @@ void PrintUsage(std::ostream* stream) {
  * - @b stdout
  *   - double-type output sequence
  *
- * In the below example, an exciation signal generated from pitch information is
- * passed through the synthesis filter built from PARCOR coefficients.
+ * In the below example, an excitation signal generated from pitch information
+ * is passed through the synthesis filter built from PARCOR coefficients.
  *
  * @code{.sh}
  *   excite < data.pitch | ltcdf data.rc > data.syn

src/main/mglsadf.cc

@@ -193,8 +193,8 @@ class InputSourcePreprocessingForMelCepstrum
  * - @b stdout
  *   - double-type output sequence
  *
- * In the below example, an exciation signal generated from pitch information is
- * passed through the MLSA filter built from mel-cepstral coefficients
+ * In the below example, an excitation signal generated from pitch information
+ * is passed through the MLSA filter built from mel-cepstral coefficients
  * @c data.mcep.
  *
  * @code{.sh}

src/main/poledf.cc

@@ -85,8 +85,8 @@ void PrintUsage(std::ostream* stream) {
  * - @b stdout
  *   - double-type output sequence
  *
- * In the below example, an exciation signal generated from pitch information is
- * passed through the standard form synthesis filter built from LPC
+ * In the below example, an excitation signal generated from pitch information
+ * is passed through the standard form synthesis filter built from LPC
  * coefficients.
  *
  * @code{.sh}

src/main/zerodf.cc

@@ -85,12 +85,12 @@ void PrintUsage(std::ostream* stream) {
  * - @b stdout
  *   - double-type output sequence
  *
- * In the below example, an exciation signal generated from pitch information is
- * passed through the standard form synthesis filter built from FIR filter
+ * In the below example, an excitation signal generated from pitch information
+ * is passed through the standard form synthesis filter built from FIR filter
  * coefficients.
  *
  * @code{.sh}
- *   excite < data.pitch | poledf data.fir > data.syn
+ *   excite < data.pitch | zerodf data.b > data.syn
  * @endcode
  *
  * @param[in] argc Number of arguments.