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                                                                  EXHIBIT 10(d)



                              NOTICE OF CONVERSION
                          OF SECURED CONVERTIBLE NOTE



TO:      Noise Cancellation Technologies, Inc.
         1025 West Nursery Road
         Linthicum, Maryland 21090
         Telecopy: (410) 636-5989
         Attention: Michael Parrella


         (1)     Pursuant to the terms of the attached Secured Convertible Note
(the "Note"), the undersigned hereby elects to convert $180,000 principal
amount of the Note into shares of Common Stock of Noise Cancellation
Technologies, Inc., a Delaware corporation (the "Borrower"). Capitalized terms
used herein and not otherwise defined herein have the respective meanings
provided in the Note.

         (2)     Please issue a certificate or certificates for the number of
shares of Common Stock into which such principal amount of the Note is
convertible in the name(s) specified immediately below or, if additional space
is necessary, on an attachment hereto:

         Kingdon Associates, L.P.                                         
         -----------------------------     -------------------------------
         Name                              Name
                                      
         152 West 57th Street                                             
         -----------------------------     -------------------------------
         New York, NY 10019                                               
         -----------------------------     -------------------------------
         Address                           Address
                                      
         13-3158769                                                       
         -----------------------------     -------------------------------
         SS or Tax ID Number               SS or Tax ID Number


         (3)     In the event of partial exercise, please reissue an
appropriate Note(s) for the principal balance which shall not have been
converted.

         (4)     If the shares of Common Stock issuable upon conversion of the
Note have not been registered under the Securities Act of 1933, as amended (the
"Act"), the undersigned represents and warrants that (i) such shares of Common
Stock are being acquired for the account of the undersigned for investment, and
not with a present view to, or for resale in connection with, the distribution
thereof, and that the undersigned has no present intention of distributing or
reselling such securities, in each case, other than pursuant to a registration
statement under the Act and (ii) the undersigned is an "Accredited Investor" as
defined in Regulation D under the Act. The undersigned further agrees that (A)
such securities shall not be sold or transferred unless either





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(i) they first shall have been registered under the Act and applicable state
securities laws or (ii) the Borrower first shall have been furnished with
either (x) an opinion of legal counsel (in form, substance and scope reasonably
satisfactory to Borrower) to the effect that such sale or transfer is exempt
from the registration requirements of the Act or (y) satisfactory
representations from the undersigned that the undersigned may immediately sell
all of such securities (to the extent such securities are deemed to have been
acquired on the same date) pursuant to Rule 144 under the Act (or a successor
thereto) and (B) the Borrower may place a legend on the certificate(s) for such
securities to that effect and place a stop transfer restriction in its records
relating to such securities.  Nothing in this Notice of Conversion shall limit
the Borrower's obligations under the Registration Rights Agreement and the
Purchase Agreement.


                            KINGDON ASSOCIATES, L.P.
                              By: Kingdon Capital Management Corp.,
                                   its general partner

Date:    August 12, 1996             By:  /s/ MARK KINGDON
                                         -----------------------------------
                                         Mark Kingdon, President
                                         (must be signed exactly as name 
                                         appears in the Note. The signature must
                                         be guaranteed by a member firm of the 
                                         New York Stock Exchange or the
                                         National Association of Securities 
                                         Dealers or by a commercial bank or
                                         trust having an office in the United 
                                         States)




cc:   John B. Horton, Esquire (by telecopier (203) 348-4106)





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                              NOTICE OF CONVERSION
                          OF SECURED CONVERTIBLE NOTE



TO:      Noise Cancellation Technologies, Inc.
         1025 West Nursery Road
         Linthicum, Maryland 21090
         Telecopy: (410) 636-5989
         Attention: Michael Parrella


         (1)     Pursuant to the terms of the attached Secured Convertible Note
(the "Note"), the undersigned hereby elects to convert $300,000 principal
amount of the Note into shares of Common Stock of Noise Cancellation
Technologies, Inc., a Delaware corporation (the "Borrower"). Capitalized terms
used herein and not otherwise defined herein have the respective meanings
provided in the Note.

         (2)     Please issue a certificate or certificates for the number of
shares of Common Stock into which such principal amount of the Note is
convertible in the name(s) specified immediately below or, if additional space
is necessary, on an attachment hereto:

         Kingdon Partners, L.P.                                                
         ------------------------------    ------------------------------------
         Name                              Name
                                       
         152 West 57th Street                                                  
         ------------------------------    ------------------------------------
         New York, NY 10019                                                    
         ------------------------------    ------------------------------------
         Address                           Address
                                       
         13-3167187                                                            
         ------------------------------    ------------------------------------
         SS or Tax ID Number               SS or Tax ID Number


         (3)     In the event of partial exercise, please reissue an
appropriate Note(s) for the principal balance which shall not have been
converted.

         (4)     If the shares of Common Stock issuable upon conversion of the
Note have not been registered under the Securities Act of 1933, as amended (the
"Act"), the undersigned represents and warrants that (i) such shares of Common
Stock are being acquired for the account of the undersigned for investment, and
not with a present view to, or for resale in connection with, the distribution
thereof, and that the undersigned has no present intention of distributing or
reselling such securities, in each case, other than pursuant to a registration
statement under the Act and (ii) the undersigned is an "Accredited Investor" as
defined in Regulation D under the Act. The undersigned further agrees that (A)
such securities shall not be sold or transferred unless either





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(i) they first shall have been registered under the Act and applicable state
securities laws or (ii) the Borrower first shall have been furnished with
either (x) an opinion of legal counsel (in form, substance and scope reasonably
satisfactory to Borrower) to the effect that such sale or transfer is exempt
from the registration requirements of the Act or (y) satisfactory
representations from the undersigned that the undersigned may immediately sell
all of such securities (to the extent such securities are deemed to have been
acquired on the same date) pursuant to Rule 144 under the Act (or a successor
thereto) and (B) the Borrower may place a legend on the certificate(s) for such
securities to that effect and place a stop transfer restriction in its records
relating to such securities.  Nothing in this Notice of Conversion shall limit
the Borrower's obligations under the Registration Rights Agreement and the
Purchase Agreement.



                               KINGDON PARTNERS, L.P.
                                 By: Kingdon Capital Management Corp.,
                                      its general partner
                               
Date:    August 12, 1996              By: /s/ MARK KINGDON
                                         ----------------------------------
                                         Mark Kingdon, President
                                         (must be signed exactly as name 
                                         appears in the Note. The signature must
                                         be guaranteed by a member firm of the 
                                         New York Stock Exchange or the
                                         National Association of Securities 
                                         Dealers or by a commercial bank or
                                         trust having an office in the United 
                                         States)




cc:   John B. Horton, Esquire (by telecopier (203) 348-4106)





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                              NOTICE OF CONVERSION
                          OF SECURED CONVERTIBLE NOTE



TO:      Noise Cancellation Technologies, Inc.
         1025 West Nursery Road
         Linthicum, Maryland 21090
         Telecopy: (410) 636-5989
         Attention: Michael Parrella


         (1)     Pursuant to the terms of the attached Secured Convertible Note
(the "Note"), the undersigned hereby elects to convert $720,000 principal
amount of the Note into shares of Common Stock of Noise Cancellation
Technologies, Inc., a Delaware corporation (the "Borrower"). Capitalized terms
used herein and not otherwise defined herein have the respective meanings
provided in the Note.

         (2)     Please issue a certificate or certificates for the number of
shares of Common Stock into which such principal amount of the Note is
convertible in the name(s) specified immediately below or, if additional space
is necessary, on an attachment hereto:

         M. Kingdon Offshore NV                                             
         -----------------------------     ---------------------------------
         Name                              Name
                                      
         152 West 57th Street                                               
         -----------------------------     ---------------------------------
         New York, NY 10019                                                 
         -----------------------------     ---------------------------------
         Address                           Address
                                      
                 N/A                                                        
         -----------------------------     ---------------------------------
         SS or Tax ID Number               SS or Tax ID Number


         (3)     In the event of partial exercise, please reissue an
appropriate Note(s) for the principal balance which shall not have been
converted.

         (4)     If the shares of Common Stock issuable upon conversion of the
Note have not been registered under the Securities Act of 1933, as amended (the
"Act"), the undersigned represents and warrants that (i) such shares of Common
Stock are being acquired for the account of the undersigned for investment, and
not with a present view to, or for resale in connection with, the distribution
thereof, and that the undersigned has no present intention of distributing or
reselling such securities, in each case, other than pursuant to a registration
statement under the Act and (ii) the undersigned is an "Accredited Investor" as
defined in Regulation D under the Act. The undersigned further agrees that (A)
such securities shall not be sold or transferred unless either





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(i) they first shall have been registered under the Act and applicable state
securities laws or (ii) the Borrower first shall have been furnished with
either (x) an opinion of legal counsel (in form, substance and scope reasonably
satisfactory to Borrower) to the effect that such sale or transfer is exempt
from the registration requirements of the Act or (y) satisfactory
representations from the undersigned that the undersigned may immediately sell
all of such securities (to the extent such securities are deemed to have been
acquired on the same date) pursuant to Rule 144 under the Act (or a successor
thereto) and (B) the Borrower may place a legend on the certificate(s) for such
securities to that effect and place a stop transfer restriction in its records
relating to such securities.  Nothing in this Notice of Conversion shall limit
the Borrower's obligations under the Registration Rights Agreement and the
Purchase Agreement.



                            M. KINGDON OFFSHORE NV
                              By: Kingdon Capital Management Corp.,
                                   its investment advisor
                          
Date:    August 12, 1996             By: /s/ MARK KINGDON
                                        ---------------------------------------
                                        Mark Kingdon, President
                                        (must be signed exactly as name appears
                                        in the Note. The signature must
                                        be guaranteed by a member firm of the 
                                        New York Stock Exchange or the
                                        National Association of Securities 
                                        Dealers or by a commercial bank or
                                        trust having an office in the United 
                                        States)
                          



cc:   John B. Horton, Esquire (by telecopier (203) 348-4106)




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