/// <summary>
        /// Sets the volume of the voicer.
        /// </summary>
        /// <param name="volumeOfVoicer">
        ///
        /// </param>
        /// <returns></returns>
        public void SetVolume(VolumeOfVoicer volumeOfVoicer)
        {
            this.volumeOfVoicer = volumeOfVoicer;

            switch (volumeOfVoicer)
            {
            case VolumeOfVoicer.NoVolume:
                textVoicer.Volume = 0;
                break;

            case VolumeOfVoicer.Low:
                textVoicer.Volume = 25;
                break;

            case VolumeOfVoicer.Medium:
                textVoicer.Volume = 50;
                break;

            case VolumeOfVoicer.High:
                textVoicer.Volume = 75;
                break;

            case VolumeOfVoicer.Max:
                textVoicer.Volume = 100;
                break;

            default:
                throw new InvalidEnumArgumentException("Invalid VolumeOfVoicer enum argument passed.");
            }
        }
        /// <summary>
        /// The class constructor.
        /// </summary>
        /// <remarks>
        /// By default it sets the speed of the voicer to Normal
        /// and the maximum volume of the voicer to Max.
        /// </remarks>
        public TextVoicerSpeechSynthesizer()
        {
            textVoicer     = new SpeechSynthesizer();
            messageBuilder = new PromptBuilder();

            speedOfVoicer  = SpeedOfVoicer.Normal;
            volumeOfVoicer = VolumeOfVoicer.Max;

            SetSpeed(speedOfVoicer);
            SetVolume(volumeOfVoicer);
        }