Exhibit 3(c)

                        CERTIFICATE OF DESIGNATIONS, PREFERENCES AND
                     RIGHTS OF SERIES C CONVERTIBLE PREFERRED STOCK OF
                           NOISE CANCELLATION TECHNOLOGIES, INC.


      Noise  Cancellation  Technologies,   Inc.,  a  corporation  organized  and
existing  under the General  Corporation  Law of the State of  Delaware  (herein
called the "Corporation"),

      DOES HEREBY CERTIFY:

      That,  pursuant to authority  conferred upon the Board of Directors of the
Corporation by the Restated Certificate of Incorporation of the Corporation, and
pursuant to the  provisions  of Section 151 of Title 8 of the  Delaware  Code of
1953, as amended, said Board of Directors, at a meeting duly held on October 22,
1997,  adopted  a  resolution  providing  for the  issuance  of a series  of ten
thousand (10,000) shares of Series C Convertible  Preferred Stock, and providing
for the powers, designations,  preferences and relative, participating, optional
or other special rights and qualifications, limitations or restrictions thereof,
which resolution is as follows:

            RESOLVED,  that pursuant to the authority  expressly  granted to and
      vested in the Board of Directors of the  Corporation  by the provisions of
      Article  IV  of  the  Restated   Certificate  of   Incorporation   of  the
      Corporation,  this  Board of  Directors  hereby  creates  a series  of the
      Preferred Stock of the Corporation  with par value of $0.10 per share (the
      "Preferred  Stock")  to  consist of ten  thousand  (10,000)  shares of the
      10,000,000 authorized shares of Preferred Stock, which the Corporation now
      has  authority  to issue,  and this Board of  Directors  hereby  fixes the
      powers, designations, preferences and relative, participating, optional or
      other  special  rights and  qualifications,  limitations  or  restrictions
      thereof  of the  shares  of  such  series  (in  addition  to  the  powers,
      designations,  preferences and relative, participating,  optional or other
      special rights and  qualifications,  limitations or restrictions  thereof,
      set  forth  in  Article  IV  of  the  Certificate  of  Incorporation   not
      inconsistent with the terms of this resolution and which are applicable to
      the Preferred Stock) as follows:

      1.    Designation.

            The  designation  of said series of Preferred  Stock created by this
Resolution shall be Series C Convertible  Preferred Stock (herein called "Series
C Convertible Preferred Stock").



<PAGE>


      2.    Par Value, Stated Value and Accretion Rate.

   Each share of Series C Convertible  Preferred Stock shall have a par value of
$0.10,  and a stated value (face amount) of One Thousand  Dollars  ($1,000) (the
"Stated  Value"),  with an accretion  rate of four percent (4%) per annum on the
Stated Value for the purposes and on the terms set forth herein.

      3.    Dividends.

            The Series C Convertible Preferred Stock will bear no dividends, and
the holders of the Series C Convertible Preferred Stock shall not be entitled to
the receipt of dividends on the Series C Convertible Preferred Stock.

      4.    Liquidation Preference.

   a.  In the  event  of  any  liquidation,  dissolution  or  winding-up  of the
Corporation,  either voluntary or involuntary (a "Liquidation"),  the holders of
record of shares of the Series C  Convertible  Preferred  Stock then  issued and
outstanding  (the  "Series C  Holders")  shall be entitled to be paid out of the
assets  of the  Corporation  available  for  distribution  to its  shareholders,
whether from capital,  surplus or earnings,  before any payment shall be made to
the holders of shares of the Common  Stock of the  Corporation,  par value $0.01
per share,  (the "Common  Stock") or upon any other series of Preferred Stock of
the  Corporation,  an amount per share  equal to the sum of (i) one  hundred ten
percent (110%) of the Stated Value and (ii) an amount equal to four percent (4%)
of the Stated Value multiplied by the fraction N/365,  where N equals the number
of days elapsed  since the issue date of Series C Convertible  Preferred  Stock.
If,  upon any  Liquidation  of the  Corporation,  the assets of the  Corporation
available for distribution to its shareholders  shall be insufficient to pay the
Series C Holders and the holders of any other series of  Preferred  Stock with a
liquidation  preference  equal to the  liquidation  preference  of the  Series C
Convertible Preferred Stock the full amounts to which they shall respectively be
entitled,  the Series C Holders and the holders of any other series of Preferred
Stock with  liquidation  preference  equal to the liquidation  preference of the
Series C  Convertible  Preferred  Stock  shall  receive all of the assets of the
Corporation  available  for  distribution  and each such Series C Holder and the
holders of any other series of  Preferred  Stock with a  liquidation  preference
equal to the liquidation  preference of the Series C Convertible Preferred Stock
shall share ratably in any  distribution in accordance with the amounts due such
shareholders.  After payment shall have been made to the Series C Holders of the
full amount to which they shall be entitled, as aforesaid,  the Series C Holders
shall be entitled to no further  distributions thereon and the holders of shares
of the  Common  Stock  and of  shares  of  any  other  series  of  stock  of the
Corporation shall be entitled to share, according to their respective rights and
preferences,   in  all  remaining  assets  of  the  Corporation   available  for
distribution to its shareholders.

            b. A merger or  consolidation  of the  Corporation  with or into any
other corporation, or a sale, lease, exchange, or transfer of all or any part of
the assets of the  Corporation  which shall not in fact result in a  Liquidation
(in whole or in part) of the Corporation  and the  distribution of its assets to
its  shareholders  shall  not  be  deemed  to  be  a  voluntary  or  involuntary
Liquidation (in whole or in part) of the Corporation.

      5.    Redemption and Repurchase.

            a. The Corporation,  at the option of its Board of Directors,  shall
have the right at any time to redeem the Series C Convertible Preferred Stock in
whole  (and  not in  part)  at a  redemption  price  equal to the sum of (i) one
hundred ten percent  (110%) of the Stated Value and (ii) an amount equal to four
percent  (4%) of the Stated Value  multiplied  by the  fraction  N/365,  where N
equals  the  number  of  days  elapsed  from  the  issue  date of the  Series  C
Convertible  Preferred  Stock to the date of  redemption  fixed by the  Board of
Directors.  Notice of such  redemption and the redemption date shall be given to
the  Series C Holders  by mail or in such  other  manner as may be  provided  by
resolution of the Board of Directors,  not more than six months nor less than 30
days prior to the date fixed for such redemption. Any notice given by mail shall
be deemed given when mailed by registered or certified mail postage prepaid,  or
when delivered  personally to the Series C Holders at their respective addresses
as the same shall then appear on the books of the Corporation.  If any notice of
redemption shall have been given as aforesaid and if on or before the redemption
date the funds  necessary for such  redemption  shall have been set aside by the
Corporation,  separate and apart from its other funds, in trust for the pro rata
benefit of the Holders of the shares so called for  redemption,  then,  from and
after the redemption date,  notwithstanding  that any certificates for shares so
called for redemption  shall not have been  surrendered  for  cancellation,  the
shares  represented  thereby  shall  not be  deemed  outstanding,  the  right to
accretion  thereon shall cease to accrue from and after the redemption  date and
all  rights of the  Series C Holders  of the  shares  so called  for  redemption
(including, but not limited to, rights of conversion) shall forthwith, after the
redemption  date,  cease and terminate,  excepting only the right to receive the
redemption  price therefor,  but without  interest or other  additional  payment
except as set forth in the first sentence of this Section 5; provided,  however,
that the conversion  rights of the Series C Holders shall continue from the date
of notice of redemption  until the close of business on the redemption date. Any
moneys so set aside by the  Corporation  and  unclaimed  at the end of six years
from the redemption  date shall revert to the general funds of the  Corporation,
after which reversion of such funds shall become contributions to the capital of
the Corporation and the Series C Holders shall have no further claim or right to
such funds.  If any shares of the Series C  Convertible  Preferred  Stock of the
Corporation shall have been redeemed,  purchased or otherwise  reacquired by the
Corporation  in  accordance  with the  laws of the  State  of  Delaware  or this
Certificate, the Board of Directors may, without any action by the stockholders,
insofar as is permissible  under the laws of the State of Delaware,  at any time
or from time to time,  eliminate all or part of such shares from the  authorized
number of shares of Series C Convertible Preferred Stock of the Corporation.

      6.    Conversion of Series C Convertible Preferred Stock.

            a. Rights to Convert.  Each share of Series C Convertible  Preferred
Stock shall be convertible, on the Conversion Dates and at the Conversion Prices
set forth  below,  into  fully  paid and  nonassessable  shares of Common  Stock
(sometimes referred to herein as "Conversion  Shares") subject to the limitation
set forth below in paragraph g of this Section 6.

            b.  Mechanics  of  Conversion.  Each  Series C Holder who desires to
convert  shares of Series C  Convertible  Preferred  Stock into shares of Common
Stock shall provide notice ("Conversion  Notice") via telecopy  (facsimile) on a
business day, during business hours in Linthicum,  Maryland, to the Corporation,
and  a  facsimile  of  the  Conversion   Notice  shall  be  transmitted  to  the
Corporation's  Transfer  Agent at the same time as  transmission  is made to the
Corporation.  On the same day, the original Conversion Notice shall be delivered
to the Corporation but the certificate or certificates representing the Series C
Convertible Preferred Stock for which conversion is elected,  shall be delivered
to the Transfer Agent by international  courier, duly endorsed. The later of the
date upon which the Corporation  receives the original  Conversion Notice or the
date the Transfer  Agent  receives the  Certificates  representing  the Series C
Convertible Preferred Stock for which conversion is elected,  shall be a "Notice
Date".

                  Upon receipt by the  Corporation  of a Conversion  Notice,  as
provided above, the Corporation  shall  immediately send to the Series C Holder,
via telecopy  (facsimile),  a confirmation  of receipt of the Conversion  Notice
which shall  specify that the  Conversion  Notice has been received and the name
and telephone  number of a contact person at the  Corporation  whom the Series C
Holder should  contact  regarding  information  related to the  conversion.  The
Corporation  shall use all  reasonable  efforts to issue and deliver within five
(5) business  days after the Notice Date, to such Series C Holder at the address
of the Series C Holder on the stock books of the  Corporation,  a certificate or
certificates  for the  number of shares  of Common  Stock to which the  Series C
Holder shall be entitled as  aforesaid;  provided  that the  original  shares of
Series  C  Convertible  Preferred  Stock to be  converted  are  received  by the
transfer  agent or the  Corporation  within  three (3)  business  days after the
receipt of the original  Conversion Notice and the person or persons entitled to
receive  the  shares of Common  Stock  issuable  upon such  conversion  shall be
treated  for all  purposes  as the record  holder or  holders of such  shares of
Common Stock on the Notice Date. If the original certificate(s) representing the
shares of Series C Convertible  Preferred Stock to be converted are not received
by the transfer  agent or the  Corporation  within three (3) business days after
the receipt of the  original  Conversion  Notice,  the  Conversion  Notice shall
become null and void, the Series C Holder shall be so notified, and the Series C
Holder shall be required to initiate a new Conversion  Notice in order to effect
conversion hereunder.

            c. Lost or Stolen  Certificates.  Upon receipt by the Corporation of
evidence  reasonably  satisfactory  to it of the  loss,  destruction,  theft  or
mutilation  of any  Series  C  Convertible  Preferred  Stock  certificates  (the
"Certificates")  and (in the case of loss, theft or destruction) of indemnity or
security  reasonably  satisfactory  to the  Corporation,  and upon surrender and
cancellation of the  Certificates,  if mutilated,  the Corporation shall execute
and deliver new Series C Convertible  Preferred Stock Certificates of like tenor
and date. However,  the Corporation shall not be obligated to re-issue such lost
or stolen  Series C Convertible  Preferred  Stock  Certificates  if the Series C
Holder thereof contemporaneously requests the Corporation to convert such Series
C Convertible  Preferred Stock into Common Stock, in which event the Corporation
shall be entitled to rely on an affidavit of loss,  destruction  or theft of the
Series C Convertible  Preferred Stock  Certificate (and the receipt of indemnity
or  security  reasonably  satisfactory  to the  Corporation)  or, in the case of
mutilation,  tender of the mutilated certificate, and shall issue the Conversion
Shares.

            d. Conversion  Dates.  The shares of Series C Convertible  Preferred
Stock  shall  become  convertible  into  shares  of  Common  Stock  at any  time
commencing  after  the  earlier  of (i) the  effective  date  of a  registration
statement  covering the  Conversion  Shares;  or (ii) ninety (90) days after the
date of filing of the registration statement covering the Conversion Shares. The
date on which a Conversion Notice is transmitted by facsimile to the Corporation
shall be referred to as a "Conversion Date".

            e.  Conversion  Formula/Conversion  Price.  Each  share of  Series C
Convertible  Preferred  Stock shall be convertible  into the number of shares of
Common  Stock  in  accordance  with  the  following   formula  (the  "Conversion
Formula"):

                                     [(.04) x (N/365) x (1,000)] + 1,000
                                               Conversion Price

      where

            N           = the number of days between (i) the Closing Date of the
                        Series C Convertible  Preferred  Stock being  converted,
                        and (ii) the Conversion Date thereof.

            Conversion
            Price       = the  lesser  of (x) 120% of the  five (5) day  average
                        Closing Bid Price of Common Stock  immediately  prior to
                        the Closing Date of the Series C  Convertible  Preferred
                        Stock being  converted or (y) 20% below the five (5) day
                        average  Closing Bid Price of Common  Stock  immediately
                        prior to the Conversion Date thereof.

            Closing
            Date        =  the  date  of  the   Closing  as  set  forth  in  the
                        subscription   agreement  pertaining  to  the  Series  C
                        Convertible Preferred Stock being converted.

                  For purposes  hereof,  the term "Closing Bid Price" shall mean
the closing bid price for a specified date on the Nasdaq  National Stock Market,
or if no longer traded thereon,  the closing bid price on the principal national
securities  exchange on which the Common Stock is so traded, or if not traded on
any such  exchange,  the last bid price on the  principal  market for the Common
Stock.

            f.  Automatic  Conversion.   Each  share  of  Series  C  Convertible
Preferred  Stock  outstanding  on  November  30,  1999  automatically  shall  be
converted  into  Common  Stock on such date in  accordance  with the  Conversion
Formula and the Conversion Price then in effect,  and November 30, 1999 shall be
deemed  to be the  Notice  Date and the  Conversion  Date with  respect  to such
conversion.

            g. Absolute  Limit on  Conversion.  Notwithstanding  anything to the
contrary  contained  in  paragraph  e. of this  Section 6, in no event shall the
Closing  Bid Price of Common  Stock to be used for  purposes  of the  Conversion
Formula set forth in paragraph e. be less than $0.625 per share. Moreover, in no
event shall the Corporation be obligated to issue more than 26,000,000 shares of
its Common Stock in the  aggregate in connection  with the  conversion of any or
all of the Series C Convertible Preferred Stock. Once the Corporation has issued
26,000,000  shares of its Common Stock in the aggregate in  connection  with the
conversion of Series C Convertible  Preferred Stock,  any remaining  outstanding
shares  of  Series  C  Convertible  Preferred  Stock  shall  cease  to have  any
conversion  rights. If at the time the limitation on conversion  provided for in
this paragraph becomes effective,  the Corporation is in receipt of a Conversion
Notice or  Conversion  Notices  pertaining  to  shares  of Series C  Convertible
Preferred Stock which have not been converted and with respect to which complete
conversion  would  exceed such  limitation,  the  Corporation  shall  effect the
conversion of such shares of Series C Convertible  Preferred Stock in accordance
with the  Conversion  Formula  and the  Conversion  Price  then in effect to the
extent the  Corporation  can do so without  exceeding  such  limitation,  in the
chronological  order of its receipt of the Conversion  Notices pertaining to the
conversion of such shares of Series C Convertible  Preferred Stock. In the event
there are insufficient  Conversion Shares to effect the conversion of all of the
shares of Series C Convertible  Preferred  Stock which are the subject of two or
more  Conversion  Notices  received  by the  Corporation  on the same date,  the
remaining  Conversion  Shares  shall be applied  toward the  conversion  of such
shares of Series C  Convertible  Preferred  Stock and  delivered  to the Class C
Holders thereof pro rata in accordance  with their then  respective  holdings of
unconverted  shares of Series C Convertible  Preferred  Stock.  Series C Holders
holding shares of Series C Convertible Preferred Stock which cannot be converted
to Common Stock of the  Corporation  because of the limitation set forth in this
paragraph  shall have the right to require by written notice to the  Corporation
that the Corporation redeem their  unconvertible  shares of Series C Convertible
Preferred Stock in accordance with the terms of Section 5 above. The Corporation
shall  promptly  notify such Series C Holders of the  termination  of conversion
rights  pursuant to this  paragraph  g. and shall issue a  redemption  notice in
accordance with Section 5 above within thirty (30) days after such termination.

            h.  No  Fractional  Shares.  If  any  conversion  of  the  Series  C
Convertible Preferred Stock would create a fractional share of Common Stock or a
right to acquire a fractional share of Common Stock, no fractional  shares shall
be issued and an equivalent of the fractional share shall be paid in cash.

            i.  Reservation of Stock Issuable Upon  Conversion.  The Corporation
shall at all times reserve and keep available out of its authorized but unissued
shares of Common Stock,  solely for the purpose of effecting  the  conversion of
the shares of the  Series C  Convertible  Preferred  Stock,  such  number of its
shares of Common  Stock as shall from time to time be  sufficient  to effect the
conversion of all then outstanding shares of the Series C Convertible  Preferred
Stock; and if at any time the number of authorized but unissued shares of Common
Stock shall not be sufficient to effect the  conversion of all then  outstanding
shares of the Series C Convertible  Preferred  Stock,  the Corporation will take
such  corporate  action as may be  necessary  to  increase  its  authorized  but
unissued  shares of Common Stock to such number of shares as shall be sufficient
for such purpose.

            j.    Adjustment to Conversion Price.

                  (i) If,  prior to the  conversion  of all  shares  of Series C
Convertible Preferred Stock, the number of outstanding shares of Common Stock is
increased  by a stock  split,  stock  dividend,  or  other  similar  event,  the
Conversion  Price  shall  be  proportionately  reduced,  or  if  the  number  of
outstanding shares of Common Stock is decreased by a reverse stock split or by a
combination  or   reclassification  of  shares,  or  other  similar  event,  the
Conversion Price shall be proportionately increased.

                  (ii) If,  prior to the  conversion  of all  shares of Series C
Convertible Preferred Stock, there shall be any merger, consolidation,  exchange
of shares, recapitalization, reorganization, or other similar event, as a result
of which  shares of Common  Stock of the  Corporation  shall be changed into the
same or a different  number of shares of the same or another class or classes of
stock or  securities of the  Corporation  or another  entity,  then the Series C
Holders shall  thereafter have the right to purchase and receive upon conversion
of shares of Series C Convertible  Preferred Stock,  upon the basis and upon the
terms and conditions  specified herein and in lieu of the shares of Common Stock
immediately  theretofore  issuable upon conversion,  such shares of stock and/or
securities  as may be issued or payable  with  respect to or in exchange for the
number of  shares  of  Common  Stock  immediately  theretofore  purchasable  and
receivable upon the conversion of shares of Series C Convertible Preferred Stock
held by such  Series C  Holders  had such  merger,  consolidation,  exchange  of
shares, recapitalization or reorganization not taken place, and in any such case
appropriate provisions shall be made with respect to the rights and interests of
the Series C Holders to the end that the provisions hereof  (including,  without
limitation,  provisions for adjustment of the Conversion Price and of the number
of shares issuable upon conversion of the Series C Convertible  Preferred Stock)
shall  thereafter be applicable,  as nearly as may be practicable in relation to
any  shares of stock or  securities  thereafter  deliverable  upon the  exercise
hereof.  The  Corporation  shall not effect any  transaction  described  in this
subsection  unless  the  resulting  successor  or  acquiring  entity (if not the
Corporation)  assumes by written  instrument  the  obligation  to deliver to the
Series C Holders such shares of stock and/or  securities as, in accordance  with
the foregoing provisions, the Series C Holders may be entitled to purchase.

                  (iii) If any adjustment  under this subsection  would create a
fractional  share of Common  Stock or a right to acquire a  fractional  share of
Common  Stock,  no  fractional  shares  shall be issued upon  conversion  and an
equivalent of the fractional share shall be paid in cash.

      7.    Voting.

            a. Except as otherwise  provided  below or by the  Delaware  General
Corporation Law, the Series C Holders shall have no voting power whatsoever, and
no Series C Holder  shall vote or otherwise  participate  in any  proceeding  in
which actions shall be taken by the Corporation or the  shareholders  thereof or
be entitled to  notification  as to any meeting of the Board of Directors or the
shareholders.

            b. Notwithstanding the above, the Corporation shall provide Series C
Holders with notification of any meeting of the shareholders regarding any major
corporate events  affecting the  Corporation.  In the event of any taking by the
Corporation  of a record of its  shareholders  for the  purpose  of  determining
shareholders  who are  entitled  to  receive  payment of any  dividend  or other
distribution,  any right to subscribe  for,  purchase or  otherwise  acquire any
share of any class or any other  securities  or  property  (including  by way of
merger, consolidation or reorganization),  or to receive any other right, or for
the purpose of determining  shareholders  who are entitled to vote in connection
with any proposed sale, lease or conveyance of all or  substantially  all of the
assets of the Corporation,  or any proposed liquidation,  dissolution or winding
up of the  Corporation,  the  Corporation  shall  mail a notice to the  Series C
Holders,  at least ten (10) days prior to the record date specified therein,  of
the date on which  any  such  record  is to be  taken  for the  purpose  of such
dividend,  distribution,  right or other event, and a brief statement  regarding
the amount and character of such dividend, distribution, right or other event to
the extent known at such time.

            c. To the extent that,  under Delaware law, the vote of the Series C
Holders,  voting  separately as a class, is required to authorize a given action
of the  Corporation,  the affirmative vote or consent of the Series C Holders of
at least a majority of the shares of the Series C  Convertible  Preferred  Stock
represented  at a duly hold  meeting  at which a quorum is present or by written
consent  of the  shares as  required  by  Delaware  law of Series C  Convertible
Preferred  Stock (except as otherwise may be required  under Delaware law) shall
constitute  the  approval of such action by the class.  To the extent that under
Delaware  law the Series C Holders are entitled to vote on a matter with holders
of Common  Stock,  voting  together  as one (1)  class,  each  share of Series C
Convertible  Preferred Stock shall be entitled to a number of votes equal to the
number of shares of Common  Stock  into which it is then  convertible  using the
record date for the taking of such vote of  shareholders as the date as of which
the Conversion Price is calculated.  The Series C Holders also shall be entitled
to notice of all shareholder  meetings or written consents with respect to which
they would be entitled to vote,  which notice would be provided  pursuant to the
Corporation's by-laws and applicable statutes.

      8.    Protective Provisions.

            a. So long as  shares of Series C  Convertible  Preferred  Stock are
outstanding, the Corporation shall not, without first obtaining the approval (by
vote or written consent, as provided by law) of the Series C Holders of at least
seventy-five   percent  (75%)  of  the  then  outstanding  shares  of  Series  C
Convertible Preferred Stock:

                  (i) alter or change the rights,  preferences  or privileges of
the Series C Convertible  Preferred Stock so as to affect adversely the Series C
Convertible Preferred Stock;

                  (ii)  create  any new  class or  series  of stock or issue any
capital stock senior to or having a preference  over or parity with the Series C
Convertible  Preferred  Stock  with  respect to  payments  upon  Liquidation  or
increase the number of authorized shares of Series C Convertible Preferred Stock
or change the Stated Value thereof; or

                  (iii) do any act or thing not authorized or contemplated under
this  Certificate  which would result in taxation of the Series C Holders  under
Section 305 of the Internal  Revenue Code of 1986, as amended (or any comparable
provision of the Internal Revenue Code as hereafter from time to time amended).

      9.    Status of Converted Stock.

            In the event any  shares of  Series C  Convertible  Preferred  Stock
shall be converted as contemplated by this Certificate,  the shares so converted
shall be  canceled,  shall  return to the  status  of  authorized  but  unissued
Preferred Stock of no designated  class or series,  and shall not be issuable by
the Corporation as Series C Convertible Preferred Stock.

      10.   Taxes.

            All  shares of  Common  Stock  issued  upon  conversion  of Series C
Convertible   Preferred   Stock   will  be  validly   issued,   fully  paid  and
nonassessable.  The  Corporation  shall  pay any and all  documentary  stamp  or
similar  issue or transfer  taxes that may be payable in respect of any issue or
delivery  of shares  of  Common  Stock on  conversion  of  Series C  Convertible
Preferred Stock pursuant hereto. The Corporation shall not, however, be required
to pay any tax which may be payable in respect of any  transfer  involved in the
issue and  delivery of shares of Common Stock in a name other than that in which
the Series C Convertible  Preferred Stock so converted were  registered,  and no
such issue or delivery shall be made unless and until the person requesting such
transfer  has  paid  to  the  Corporation  the  amount  of any  such  tax or has
established to the  satisfaction of the Corporation  that such tax has been paid
or that no such tax is payable.

      IN WITNESS WHEREOF, said Noise Cancellation Technologies,  Inc. has caused
this  Certificate  to be signed by  Michael  J.  Parrella,  its  President,  and
attested by John B. Horton, its Secretary, the 28th day of October, 1997.

[Seal]                                    NOISE CANCELLATION TECHNOLOGIES, INC.

                                          By:   /s/ MICHAEL J. PARRELLA
                                                -----------------------
                                                President
ATTEST:

By:   /s/ JOHN B. HORTON
      ------------------
      Secretary