Exhibit 10(a)


                      EXCHANGE RIGHTS AND RELEASE AGREEMENT


Exchange Rights and Release Agreement ("Agreement"), dated as of April 10, 2003,
among NCT Group,  Inc.  ("NCT"),  Pro Tech  Communications,  Inc.,  an  indirect
subsidiary of NCT ("Pro  Tech"),  Alpha  Capital  Aktiengesellschaft  ("Alpha"),
Austost Anstalt Schaan  ("Austost"),  Balmore,  S.A. (f/k/a Balmore Funds, S.A.)
("Balmore") and Libra Finance,  S.A. ("Libra" and, collectively with Austost and
Balmore, the "Investors").

The parties hereto agree as follows:

1.   Exchange Right.

(a)  As of the date  hereof,  the  Investors  are the holders of an aggregate of
     3,154  shares of Artera  Group,  Inc.  ("Artera")  4% Series A  Convertible
     Preferred  Stock,  par value $.10 per share (the "Investor Artera Preferred
     Shares"), as follows: Austost 1,077 shares evidenced by certificates number
     P-23 (303 shares) and P-24 (774 shares);  Balmore 1,077 shares evidenced by
     certificates  number  P-21 (303  shares) and P-22 (774  shares);  and Libra
     1,000 shares evidenced by certificates number P-3 (500 shares) and P-6 (500
     shares).

(b)  NCT hereby grants the  Investors the right to exchange the Investor  Artera
     Preferred  Shares and all accretion  thereon for shares of preferred stock,
     par value $.10 per share,  of NCT (the "NCT Preferred  Shares"),  which NCT
     Preferred  Shares  shall have a stated value per share equal to that of the
     Investor Artera  Preferred Shares and shall have other terms and conditions
     relating  thereto that are  identical or  substantially  identical to those
     relating to the Investor Artera Preferred Shares.

(c)  The foregoing exchange right may be exercised,  in whole or in part, via 30
     days' prior  written  notice to NCT (in the case of the first such exercise
     by any of the  Investors) or via 10 days' prior  written  notice to NCT (in
     the case of all subsequent exercises by the Investors).

(d)  The  Investors  acknowledge  that,  as of the  date  hereof,  NCT  has  not
     designated a series of its preferred stock that satisfies the  requirements
     herein;  NCT  shall be  obligated,  prior to the end of the  30-day  notice
     period of the first  exercise  as  described  above,  to  designate  such a
     series.

(e)  The foregoing  exchange right is in addition to any right the Investors may
     have to exchange their Investor Artera  Preferred  Shares for shares of NCT
     common  stock,  par value $.01 per share,  pursuant to the Exchange  Rights
     Agreement (Preferred),  dated as of June 29, 2001, among NCT, the Investors
     and others.  However,  any exchange of Investor Artera Preferred Shares for
     NCT Preferred  Shares under this Agreement shall  automatically  extinguish
     the  exchanging  Investor's  rights under such  Exchange  Rights  Agreement
     (Preferred),  with  respect  to the  Investor  Artera  Preferred  Shares so
     exchanged hereunder.

2.   Release.

(a)  Pursuant  to  a  Securities  Purchase  and  Supplemental   Exchange  Rights
     Agreement,  dated as of July 30, 2001, among Alpha, Pro Tech and NCT, Alpha
     purchased  from Pro Tech 500  shares  of Pro Tech 4%  Series B  Convertible
     Preferred  Stock,  par value $.01 per share (the "Alpha Pro Tech  Preferred
     Shares"),  evidenced  by  certificate  number  P-1.  Under the  Articles of
     Amendment  to  Articles of  Incorporation  of Pro Tech dated as of July 30,
     2001 (the  "Articles"),  Alpha has the right to convert  the Alpha Pro Tech
     Preferred  Shares into shares of Pro Tech common stock, par value $.001 per
     share (the  "Conversion  Shares"),  under terms and conditions set forth in
     the Articles. Pursuant to a Registration Rights Agreement, dated as of July
     30, 2001 (the "Registration Rights Agreement"), between Pro Tech and Alpha,
     Pro Tech agreed to certain undertakings with respect to the registration of
     the Conversion  Shares.  As of the date hereof,  none of the Alpha Pro Tech
     Preferred  Shares have been converted by Alpha into  Conversion  Shares and
     all of the Alpha Pro Tech Preferred Shares continue to be held by Alpha.

(b)  Alpha hereby waives and releases Pro Tech from any and all  obligations Pro
     Tech had, has or may in the future have under Sections 2(a),  2(b) and 2(e)
     of the  Registration  Rights  Agreement,  including  any  and  all  claims,
     penalties  and  other  consequences  arising  out of a  breach  of any such
     subsections under other provisions of the Registration Rights Agreement and
     under the Articles.

3.   Miscellaneous.  This  Agreement  represents  the  entire  agreement  of the
     parties hereto with respect to the subject  matter  hereof.  This Agreement
     shall be  governed  by and  interpreted  in  accordance  with New York law,
     without regard to the  principles of conflicts of laws.  This Agreement may
     be executed by fax. This Agreement may be executed in counterparts.


<PAGE>


IN WITNESS  WHEREOF,  the parties  hereto have caused this  Exchange  Rights and
Release Agreement to be executed as of the date first set forth above.


                                           NCT GROUP, INC.


                                           By:   /s/  Michael J. Parrella
                                               ---------------------------------
                                               Name:  Michael J. Parrella
                                               ---------------------------------
                                               Title: Chairman & C.E.O.
                                               ---------------------------------


                                           PRO TECH COMMUNICATIONS, INC.


                                           By:   /s/  Mark Melnick
                                               ---------------------------------
                                               Name:  Mark Melnick
                                               ---------------------------------
                                               Title: Secretary
                                               ---------------------------------

                                           ALPHA CAPITAL AKTIENGESELLSCHAFT


                                           By:   /s/  Konrad Ackermann
                                               ---------------------------------
                                               Name:  Konrad Ackermann
                                               ---------------------------------
                                               Title: Director
                                               ---------------------------------



                                           AUSTOST ANSTALT SCHAAN


                                           By:   /s/  Thomas Hackl
                                               ---------------------------------
                                               Name:  Thomas Hackl
                                               ---------------------------------
                                               Title: Director
                                               ---------------------------------


                                           BALMORE, S.A.


                                           By:   /s/  Francois Morax
                                               ---------------------------------
                                               Name:  Francois Morax
                                               ---------------------------------
                                               Title: Director
                                               ---------------------------------


                                           LIBRA FINANCE, S.A.


                                           By:   /s/  Seymour Brown
                                               ---------------------------------
                                               Name:  Seymour Brown
                                               ---------------------------------
                                               Title: Director
                                               ---------------------------------


ACKNOWLEDGED:

ARTERA GROUP, INC.


By    /s/  Michael J. Parrella
   -------------------------------------
   Name:   Michael J. Parrella
   -------------------------------------
   Title:  Chairman & President
   -------------------------------------