namespace WindowsFormsApplication1
{
    partial class Form1
    {
        /// <summary>
        /// Required designer variable.
        /// </summary>
        private System.ComponentModel.IContainer components = null;

        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                components.Dispose();
            }
            base.Dispose(disposing);
        }

        #region Windows Form Designer generated code

        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            this.numFreq = new System.Windows.Forms.NumericUpDown();
            this.label1 = new System.Windows.Forms.Label();
            this.label2 = new System.Windows.Forms.Label();
            this.numVol = new System.Windows.Forms.NumericUpDown();
            ((System.ComponentModel.ISupportInitialize)(this.numFreq)).BeginInit();
            ((System.ComponentModel.ISupportInitialize)(this.numVol)).BeginInit();
            this.SuspendLayout();
            // 
            // numFreq
            // 
            this.numFreq.Location = new System.Drawing.Point(152, 12);
            this.numFreq.Maximum = new decimal(new int[] {
            24000,
            0,
            0,
            0});
            this.numFreq.Name = "numFreq";
            this.numFreq.Size = new System.Drawing.Size(120, 20);
            this.numFreq.TabIndex = 0;
            this.numFreq.ValueChanged += new System.EventHandler(this.numFreq_ValueChanged);
            // 
            // label1
            // 
            this.label1.AutoSize = true;
            this.label1.Location = new System.Drawing.Point(12, 14);
            this.label1.Name = "label1";
            this.label1.Size = new System.Drawing.Size(49, 13);
            this.label1.TabIndex = 1;
            this.label1.Text = "Частота";
            // 
            // label2
            // 
            this.label2.AutoSize = true;
            this.label2.Location = new System.Drawing.Point(12, 48);
            this.label2.Name = "label2";
            this.label2.Size = new System.Drawing.Size(62, 13);
            this.label2.TabIndex = 2;
            this.label2.Text = "Громкость";
            // 
            // numVol
            // 
            this.numVol.DecimalPlaces = 2;
            this.numVol.Increment = new decimal(new int[] {
            1,
            0,
            0,
            131072});
            this.numVol.Location = new System.Drawing.Point(152, 41);
            this.numVol.Maximum = new decimal(new int[] {
            1,
            0,
            0,
            0});
            this.numVol.Name = "numVol";
            this.numVol.Size = new System.Drawing.Size(120, 20);
            this.numVol.TabIndex = 3;
            this.numVol.ValueChanged += new System.EventHandler(this.numVol_ValueChanged);
            // 
            // Form1
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(870, 413);
            this.Controls.Add(this.numVol);
            this.Controls.Add(this.label2);
            this.Controls.Add(this.label1);
            this.Controls.Add(this.numFreq);
            this.Name = "Form1";
            this.Text = "Form1";
            this.Load += new System.EventHandler(this.Form1_Load);
            ((System.ComponentModel.ISupportInitialize)(this.numFreq)).EndInit();
            ((System.ComponentModel.ISupportInitialize)(this.numVol)).EndInit();
            this.ResumeLayout(false);
            this.PerformLayout();

        }

        #endregion

        private System.Windows.Forms.NumericUpDown numFreq;
        private System.Windows.Forms.Label label1;
        private System.Windows.Forms.Label label2;
        private System.Windows.Forms.NumericUpDown numVol;

    }
}

using System;
using System.Collections.Generic;
using System.Windows.Forms;
using System.IO;
using System.Threading;
using System.Media;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent(); 
        }

        WavBuffer PlayBuffer, WriteBuffer;
        int Frequency;
        float Volume;
        Semaphore WriterSem, PlayerSem;

        private void Form1_Load(object sender, EventArgs e)
        {
            numFreq.Value = 500;
            numVol.Value = 0.75M;
            PlayBuffer = WriteBuffer = new WavBuffer();
            PlayBuffer.Next = new WavBuffer() { Next = new WavBuffer() { Next = new WavBuffer() { Next = PlayBuffer } } };

            WriterSem = new Semaphore(2, 4);
            PlayerSem = new Semaphore(0, 4);
            new Thread(new ThreadStart(WriteThread)) { IsBackground = true }.Start();
            new Thread(new ThreadStart(PlayThread)) { IsBackground = true }.Start();
        }

        private void WriteThread()
        {
            double x = 0;
            while (true)
            {
                WriterSem.WaitOne();

                int Max = WriteBuffer.File.Length;
                byte[] B = WriteBuffer.File;
                double Amp = Volume * 32700;
                double delta = Frequency * 2 * Math.PI / (44100);

                for (int i = WriteBuffer.StartOffset; i < Max; i += 2)
                {
                    double d = Amp * Math.Sin(x);
                    x += delta;
                    short s = (short)d;
                    B[i] = (byte)s;
                    B[i + 1] = (byte)(s >> 8);
                }

                WriteBuffer = WriteBuffer.Next;
                PlayerSem.Release();
            }
        }

        private void PlayThread()
        {
            SoundPlayer Player = new SoundPlayer();
            while (true)
            {
                PlayerSem.WaitOne();
                PlayBuffer.MemStream.Seek(0, SeekOrigin.Begin);
                Player.Stream = PlayBuffer.MemStream;
                Player.PlaySync();
                WriterSem.Release();
            }
        }

        private void numFreq_ValueChanged(object sender, EventArgs e)
        {
            Frequency = (int)numFreq.Value;
        }

        private void numVol_ValueChanged(object sender, EventArgs e)
        {
            Volume = (float)numVol.Value;
        }

        class WavBuffer
        {
            internal WavBuffer()
            {
                short channr = 1;
                int Hz = 44100;
                short bitpersample = 16;
                short blockalign = (short)(channr * bitpersample / 8);
                int bytesps = Hz * blockalign;
                int DataLen = bytesps * 2;
                
                int frmLen = 16;
                int FileLen = 4 + (8 + frmLen) + (8 + DataLen);
                                
                BinaryWriter BW = new BinaryWriter(new MemoryStream(), System.Text.Encoding.ASCII);
                
                BW.Write("RIFF".ToCharArray());//File Header
                BW.Write(FileLen);
                BW.Write("WAVE".ToCharArray());

                BW.Write("fmt ".ToCharArray());//Format chunk
                BW.Write(frmLen);
                BW.Write((short)1); //PCM
                BW.Write(channr);   //mono
                BW.Write(Hz);       //Hz
                BW.Write(88200);    //byte / s
                BW.Write(blockalign); //Block alighn
                BW.Write(bitpersample);//bit/sample

                BW.Write("data".ToCharArray());//Data chunk
                BW.Write(DataLen);
                BW.Write(new char[DataLen]);
                BW.Flush();

                File = (BW.BaseStream as MemoryStream).GetBuffer();
                StartOffset = File.Length - DataLen;
                MemStream = new MemoryStream(File);
            }
            
            
            public byte[] File;
            public int StartOffset;
            public WavBuffer Next;
            public MemoryStream MemStream;
        }
    }
}