10.21.4

         THE CONVERTIBLE  SENIOR SECURED NOTE DATED OCTOBER 7, 1998 MADE BY AURA
         SYSTEMS,  INC.  IN  FAVOR  OF RGC  INTERNATIONAL  INVESTORS,  LDC  (THE
         "CONVERTIBLE  SENIOR  SECURED  NOTE"),  IS HEREBY  AMENDED AND RESTATED
         EFFECTIVE AS OF OCTOBER 22, 1999. ALL  LIABILITIES  AND  OBLIGATIONS OF
         AURA SYSTEMS,  INC.  UNDER THE  CONVERTIBLE  SENIOR  SECURED NOTE SHALL
         HEREAFTER BE EVIDENCED BY THIS NOTE.


              AMENDED AND RESTATED CONVERTIBLE SENIOR SECURED NOTE


El Segundo, California                                           $3,000,000.00
October 7, 1998

                  FOR VALUE RECEIVED, Aura Systems, Inc., a Delaware corporation
(hereinafter called the "Borrower"),  hereby promises to pay to the order of RGC
International  Investors, LDC or registered assigns (the "Holder") the principal
amount of Three Million Dollars  ($3,000,000.00) in equal quarterly installments
of $283,679.00  beginning on the 22nd day of January, 2000 and continuing on the
22nd day of each successive  April,  July,  October and January until payment in
full of the  principal  amount;  provided,  however,  that if at any  time  such
quarterly  payments are less frequent than any regularly  scheduled  payments of
principal or interest to the holders of unsecured claims  ("Unsecured  Scheduled
Payments")  pursuant to any plan of  reorganization,  repayment or restructuring
between  the  Borrower  and that  certain  Unofficial  Creditors'  Committee  of
Borrower,  organized as of July 26, 1999, or any similarly  situated  committee,
then, following payment of the next quarterly  installment due after the date of
the first Unsecured Scheduled Payment,  this Note shall be thereafter payable in
equal  monthly  installments  of  $94,009.00 on the 22nd day of each month until
payment in full of the principal amount.

                  Any remaining unpaid principal balance of this Note,  together
with  accrued but unpaid  interest,  shall be due and payable in full on October
22, 2002 (the  "Maturity  Date").  The  Borrower  may prepay the  principal  and
interest  on this Note,  without  premium or  penalty,  at any time prior to the
Maturity Date.

                  Interest shall accrue on the unpaid  principal  balance hereof
at the rate of eight  percent  (8%) per annum from  October 22, 1999 (the "Issue
Date")  until the same  becomes  due and  payable,  whether at  maturity or upon
acceleration  or by prepayment or otherwise,  and shall be computed on the basis
of a 365-day  year and the  actual  number  of days  elapsed.  Accrued  interest
hereunder shall be payable in arrears on the date for principal  payments as set
forth above.  Any amount of principal or interest on this Note which is not paid
when due shall bear interest at the rate of sixteen  percent (16%) per annum (or
such  lesser  amount as is allowed by law) from the due date  thereof  until the
same is paid  ("Default  Interest"),  such  Default  Interest to be payable upon
demand.




<PAGE>





                  All payments of principal and accrued  interest  shall be made
in lawful money of the United States of America.  All payments  shall be made at
such  address as the Holder  shall  hereafter  give to the  Borrower  by written
notice made in accordance with the provisions of this Note.  Whenever any amount
expressed  to be due by the  terms of this Note is due on any day which is not a
business day, the same shall instead be due on the next  succeeding day which is
a business  day and,  in the case of any  payment  date which is not the date on
which this Note is paid in full, the extension of the due date thereof shall not
be taken into account for purposes of determining  the amount of interest due on
such date.  As used in this  Note,  the term  "business  day" shall mean any day
other than a Saturday,  Sunday or a day on which commercial banks in the city of
New York,  New York are  authorized  or  required by law or  executive  order to
remain closed.  Each  capitalized term used herein,  and not otherwise  defined,
shall have the meaning  ascribed  thereto in that  certain  Securities  Purchase
Agreement,  dated  October 7, 1998,  pursuant to which this Note was  originally
issued (the "Purchase Agreement").

                  This Note is a secured  obligation and is subject to the terms
of (i) that certain Security Agreement,  dated as of October 7, 1998 and amended
as of October  22,  1999,  by and  between  the Holder  and the  Borrower,  (the
"Borrower Security Agreement"),  (ii) those certain Guarantee Agreements,  dated
as of October 7, 1998, by and between each of the  Borrower's  subsidiaries  and
the  Holder  (the  "Guarantee  Agreements),  and (iii)  those  certain  Security
Agreements,  dated as of October 7, 1998, and amended as of October 22, 1999, by
and between each of the Borrower's  subsidiaries and the Holder (the "Subsidiary
Security  Agreements" and, together with the Borrower Security Agreement and the
Guarantee  Agreements,   the  "Security  Agreements").   All  terms,  covenants,
conditions and agreements contained in the Security Agreements are hereby made a
part of this Note as if they were fully set forth herein,  and Borrower promises
and agrees to keep,  observe and perform the same in  accordance  with the terms
thereof.

                  The Convertible Senior Secured Note dated October 7, 1998 made
by Aura  Systems,  Inc.  in  favor  of RGC  International  Investors,  LDC  (the
"Convertible  Senior  Secured  Note") is amended and  restated  effective  as of
October 22, 1999.  All  liabilities  and  obligations  of the Borrower under the
Convertible Senior Secured Note shall hereafter be evidenced by this Note.

                  Upon  the  occurrence  of an  Event  of  Default  (as  defined
herein),  the entire unpaid principal  indebtedness of this Note,  together with
all  interest  accrued  and Default  Interest  together  with all other  charges
provided  for  herein or in the  Security  Agreements,  shall,  at the option of
Holder,  become  due and  payable  immediately,  without  presentation,  demand,
protest or further notice (all of which are expressly  waived by Borrower),  and
payment of same may be enforced and recovered in whole or in part at any time by
the Holder.

                  Borrower  agrees to pay on demand any  costs,  indemnification
claims, or other expenses arising under the Security Agreements and all costs of
collection, including without limitation attorneys' fees, incurred by the Holder
hereof with respect to any default by Borrower  hereunder;  such amounts,  until
paid by Borrower,  shall be added to the principal  hereof and be secured by the
Security Agreements.



<PAGE>



                  Any and all payments received by the Holder hereof following a
default by Borrower may, at the Holder's option,  be applied to any and all sums
payable by Borrower hereunder in whatever order and manner the Holder may elect,
including,  without limitation,  the following:  first to the payment of any and
all costs and  expenses  incurred  by the Holder with  respect to such  default,
second to payments  overdue  hereunder (in whatever order the Holder may elect),
third to  accrued  interest  and fourth to  principal.  The Holder may make such
application  notwithstanding  any  contrary  request  or  purported  conditional
payment by Borrower.

                  The granting by the Holder hereof,  with or without notice, of
any  forbearance  or any  extension  of time for  payment  of any sum or for the
performance  of any covenant,  condition or agreement due hereunder or under the
Security Agreements,  or the granting of any other indulgence,  or the taking or
releasing  or  subordinating  of any  security or  additional  security  for the
indebtedness  evidenced hereby,  or any other  modification or amendment of this
Note or the  Security  Agreements,  shall in no way  release  or  discharge  the
liability  of  Borrower  on this Note,  whether or not  granted or done with the
knowledge or consent of Borrower.  No failure or delay on the part of the Holder
in the exercise of any power,  right or privilege  hereunder  shall operate as a
waiver  thereof,  nor shall any single or partial  exercise  of any such  power,
right or privilege  preclude other or further  exercise  thereof or of any other
right,  power or  privileges.  All rights and remedies  existing  hereunder  are
cumulative to, and not exclusive of, any rights or remedies otherwise available.

                  BORROWER  HEREBY  IRREVOCABLY   AUTHORIZES  AND  EMPOWERS  ANY
ATTORNEY OR THE PROTHONOTARY OR CLERK OF ANY COURT OF RECORD WITHIN THE STATE OF
DELAWARE  OR  ELSEWHERE  TO APPEAR  FOR  BORROWER  AND IN CASE ANY  DEFAULT  HAS
OCCURRED HEREUNDER OR UNDER THE SECURITY  AGREEMENTS,  WITH OR WITHOUT COMPLAINT
OR DECLARATION  FILED, TO CONFESS AND ENTER JUDGMENT,  OR A SERIES OF JUDGMENTS,
AGAINST  BORROWER IN FAVOR OF THE THEN  HOLDER OF THIS NOTE AS OF ANY TERM,  FOR
THE UNPAID BALANCE OF THE PRINCIPAL DEBT HEREOF  (INCLUDING  WITHOUT  LIMITATION
ALL SUMS  ADVANCED OR PAID BY ANY HOLDER TO OR ON BEHALF OF BORROWER OR ADDED TO
THE  PRINCIPAL  HEREOF  PURSUANT  TO THE  TERMS  OF THIS  NOTE  OR THE  SECURITY
AGREEMENTS) TOGETHER WITH UNPAID INTEREST AND DEFAULT INTEREST THEREON, COSTS OF
SUIT AND REASONABLE  ATTORNEY'S FEES AND COSTS.  THIS NOTE OR A COPY VERIFIED BY
AFFIDAVIT  SHALL BE SUFFICIENT  WARRANT FOR ANY SUCH ATTORNEY TO SO PROCEED.  ON
SUCH  JUDGMENT OR JUDGMENTS  ONE OR MORE  EXECUTIONS  MAY ISSUE  FORTHWITH.  THE
AUTHORITY  GRANTED  HEREIN TO CONFESS  JUDGMENT  SHALL NOT BE  EXHAUSTED  BY ANY
EXERCISE  THEREOF BUT SHALL  CONTINUE AND MAY BE EXERCISED FROM TIME TO TIME AND
AT ALL TIMES UNTIL  PAYMENT IN FULL OF ALL THE AMOUNTS DUE  HEREUNDER  AND UNDER
THE SECURITY AGREEMENTS, ANY LAW, RULE OF COURT OR CUSTOM NOTWITHSTANDING.




<PAGE>



                  Any notice  herein  required or permitted to be given shall be
in  writing  and may be  personally  served or  delivered  by courier or sent by
United  States  mail and  shall be deemed to have been  given  upon  receipt  if
personally served (which shall include telephone line facsimile transmission) or
sent by courier or three (3) days after  being  deposited  in the United  States
mail, certified,  with postage pre-paid and properly addressed, if sent by mail.
For the  purposes  hereof,  the  address  of the  Holder  shall be c/o Rose Glen
Capital   Management,   L.P.,  3  Bala  Plaza  East,  Suite  200,  Bala  Cynwyd,
Pennsylvania  19004,  facsimile  number:  (610)  617-0570 and the address of the
Borrower shall be Aura Systems, Inc., 2335 Alaska Avenue, El Segundo, California
90245,  facsimile number:  (310) 643-8719.  Both the Holder and the Borrower may
change the  address  for  service  by service of written  notice to the other as
herein provided.

                  This Note is transferrable at the Holder's option and shall be
binding upon  Borrower  and its  successors  and  assigns.  The rights under and
benefits  of this Note shall  inure to Holder and its  successors  and  assigns.
Notwithstanding  anything in this Note to the contrary, this Note may be pledged
as  collateral in  connection  with a bona fide margin  account or other lending
arrangement.

                  This Note and any  provision  hereof may only be amended by an
instrument in writing signed by the Borrower and the Holder. The term "Note" and
all references  thereto,  as used  throughout this  instrument,  shall mean this
instrument as originally executed, or if later amended or supplemented,  then as
so amended or supplemented.

                  If any  term  or  provision  of this  Note or the  application
thereof to any person or circumstance shall be invalid, illegal or unenforceable
in any  respect,  the  remainder  of this Note shall be  construed  without such
provision,  and  the  application  of such  term  or  provision  to  persons  or
circumstances  other  than  those  as to which it is held  invalid,  illegal  or
unenforceable,  as the case may be, shall not be affected thereby, and all other
terms and provisions of this Note shall be valid and  enforceable to the fullest
extent permitted by law and equity.

                  This   Agreement   shall  be  governed  by  and  construed  in
accordance with the laws of the State of Delaware  applicable to agreements made
and to be performed in the State of Delaware  (without  regard to  principles of
conflict of laws). Both parties  irrevocably  consent to the jurisdiction of the
United  States  federal  courts and the state  courts  located in Delaware  with
respect to any suit or proceeding based on or arising under this Agreement,  the
agreements entered into in connection herewith or the transactions  contemplated
hereby or thereby and irrevocably  agree that all claims in respect of such suit
or proceeding may be determined in such courts.  Both parties  irrevocably waive
the  defense  of an  inconvenient  forum  to the  maintenance  of  such  suit or
proceeding.  Both  parties  further  agree that  service of process upon a party
mailed by first class mail shall be deemed in every respect effective service of
process  upon the party in any such suit or  proceeding.  Nothing  herein  shall
affect either  party's  right to serve process in any other manner  permitted by
law. Both parties agree that a final non-appealable judgment in any such suit or
proceeding  shall be conclusive  and may be enforced in other  jurisdictions  by
suit on such judgment or in any other lawful manner.




<PAGE>



                  The following additional terms shall apply to this Note:

                          ARTICLE I - CERTAIN COVENANTS

                  1.1  Distributions  on Capital Stock.  So long as the Borrower
shall have any  obligation  under this Note,  the Borrower shall not without the
Holder's  written  consent (a) pay,  declare or set apart for such payment,  any
dividend or other distribution  (whether in cash,  property or other securities)
on shares of capital  stock  other than  dividends  on shares of the  Borrower's
common  stock,  par value $0.005 per share (the "Common  Stock"),  solely in the
form of  additional  shares of Common  Stock or (b)  directly or  indirectly  or
through any subsidiary  make any other payment or distribution in respect of its
capital stock.

                  1.2 Restriction on Stock Repurchases.  So long as the Borrower
shall have any  obligation  under this Note,  the Borrower shall not without the
Holder's  written consent redeem,  repurchase or otherwise  acquire (whether for
cash or in exchange for property or other  securities  or  otherwise) in any one
transaction or series of related transactions any shares of capital stock of the
Borrower  or any  warrants,  rights or options to  purchase  or acquire any such
shares;  provided,  however,  that  this  Paragraph  1.2  shall not be deemed to
prohibit (a) the repurchase by the Borrower of (i) that certain Convertible Term
Debenture,  due June 27, 1999,  issued to JNC Opportunity  Fund, Ltd., (ii) that
certain Convertible  Debenture issued on December 31, 1997 to CEFEO Investments,
Ltd., (iii) that certain note issued to Isosceles Fund Ltd. on October 27, 1998,
or (iv) those certain Variable Interest  Convertible Notes of the Company issued
on September  30, 1997,  and held by Infinity  Investors  Ltd. and certain other
funds that are advised by H.W. Finance,  in each case on terms no more favorable
than  those  given  to  Holder  pursuant  to that  certain  Securities  Purchase
Agreement,  dated as of October  13,  1999,  by and  between the Holder and Algo
Technologies, Inc., a California corporation (the "Algo Purchase Agreement"), or
(b) the  issuance by the Borrower of shares of Common Stock to each of Excalibur
Limited  Partnership,  P.R.I.F.,  L.P. and Gundyco in trust for RRSP  50-9886-19
(collectively,  the "NewCom Investors") in an amount not in excess of the shares
to which such parties are entitled  pursuant to those  certain  "Aura  Repricing
Rights"  contained in those certain  Subscription  Agreements,  each dated as of
November 30, 1998, between NewCom,  Inc. and the NewCom Investors (as amended by
that certain Amendment Agreement,  dated December 28, 1998, between NewCom, Inc.
and the NewCom Investors).

                  1.3  Sale of  Assets.  So  long as  Borrower  shall  have  any
obligation  under this Note, the Borrower shall not, and shall not permit any of
its Significant  Subsidiaries (as defined in Section 2.3 herein) to, sell, lease
or otherwise  dispose of any of its or their assets outside the ordinary  course
of business without the Holder's written consent;  provided,  however, that this
Paragraph 1.3 shall not be deemed to prohibit (a) any such disposition of assets
the  entire  proceeds  of  which  are  used to  repay  this  Note,  (b) any such
disposition  of assets by Aura  Ceramics,  Inc. or (c) any such  disposition  of
assets effected prior to October 1, 1999 by MYS Corporation, AuraSound, Inc. and
Electrotec Productions, Inc.




<PAGE>



                  1.4  Advances  and Loans.  So long as Borrower  shall have any
obligation  under this Note, the Borrower shall not without the Holder's written
consent  lend  money,  give credit or make  advances  to, or  otherwise  make an
investment  in, any  person,  firm,  joint  venture or  corporation,  including,
without limitation, officers, directors, employees,  subsidiaries and affiliates
of the Borrower, except loans, credits or advances (a) in existence or committed
on the Issue  Date and which the  Borrower  has  informed  the Holder in writing
prior to the  date  hereof,  and (b) made in the  ordinary  course  of  business
(including intercompany transactions consistent with past practice).

                  1.5 Contingent Liabilities. So long as Borrower shall have any
obligation  under this Note, the Borrower shall not without the Holder's written
consent assume, guarantee,  endorse, contingently agree to purchase or otherwise
become  liable upon the  obligation  of any  person,  firm,  partnership,  joint
venture or corporation,  except by the endorsement of negotiable instruments for
deposit or  collection  and except  assumptions,  guarantees,  endorsements  and
contingencies  (a) in  existence  or  committed  on the Issue Date and which the
Borrower has informed  the Holder in writing  prior to the date hereof,  and (b)
similar transactions in the ordinary course of business.

                  1.6  Seniority  of Note.  So long as  Borrower  shall have any
obligation  under this Note, the Borrower  shall not incur any  obligation  with
respect  to  indebtedness  which is  senior  in right of  payment  to this  Note
(including,  without  limitation,  making any  obligation  outstanding as of the
Issue Date senior in right of payment to this Note) other than  obligations with
respect to indebtedness incurred in connection with a Permitted Lien (as defined
in the Borrower  Security  Agreement);  provided,  however,  that the  foregoing
language shall not be deemed to restrict or otherwise limit  Borrower's  ability
to make  payments  with  respect  to  indebtedness  which is  junior in right of
payment to this Note to the  extent  that (i) at the time of such  payment,  the
Borrower is not  otherwise in default  under the terms of this Note and (ii) the
making  of such  payment  by the  Borrower  would not  result in the  Borrower's
inability to make payments of principal and interest hereunder.

                         ARTICLE II - EVENTS OF DEFAULT

                  The Borrower shall be in default under this Note if any one or
more of the following events (each an "Event of Default") occurs:

                  2.1 Failure to Pay Principal or Interest.  The Borrower  fails
to pay the principal  hereof or interest  thereon when due, whether at maturity,
upon acceleration or otherwise,  and such failure continues uncured for a period
of (10) days;




<PAGE>



                  2.2 Breach of  Covenants.  The Borrower  breaches any material
covenant or other material term or condition  contained in this Note or Sections
2, 3, 4, 5, 6 or 7 of the Security  Agreement or any  subsidiary of the Borrower
breaches any material  covenant or other material law or condition  contained in
Sections  2, 3, 4, 5, 6 or 7 of any  Subsidiary  Security  Agreement,  and  such
breach  continues for a period of ten (10) days after written  notice thereof to
the Borrower from the Holder;

                  2.3  Receiver or  Trustee.  The  Borrower  or any  Significant
Subsidiary  (as defined  below) of the Borrower shall make an assignment for the
benefit of creditors,  or apply for or consent to the  appointment of a receiver
or trustee for it or for a substantial part of its property or business, or such
a receiver or trustee shall  otherwise be appointed.  For purposes  hereof,  the
term "Significant Subsidiary" shall mean any subsidiary of the Borrower which on
the Issue Date fits (based upon the financial  statements of the Borrower  dated
as of and for the periods ending  September 30, 1999) or which may in the future
fit  within  the  definition  set  forth  in  Rule  1-02(w)  of  Regulation  S-X
promulgated under the Securities Act of 1933, as amended, but shall specifically
exclude NewCom, Inc.;

                  2.4 Judgments.  Any money  judgment,  writ or similar  process
shall be entered or filed against the Borrower or any Significant  Subsidiary of
the Borrower or any of its  property or other  assets for more than  $1,000,000,
and shall  remain  unvacated,  unbonded  or  unstayed  (by court order or by the
written  agreement  of the judgment  creditor)  for a period of twenty (20) days
unless otherwise  consented to by the Holder in its sole  discretion;  provided,
however,  that the  existing  judgment  against the  Borrower and certain of its
subsidiaries in favor of NEC  Technologies,  Inc.  entered in Case No. YC033592,
Los Angeles Superior Court, pursuant to a Settlement  Agreement,  dated December
17, 1998, in the amount of $2,951,854  (plus  interest)  shall not constitute an
Event of Default under this Paragraph 2.4;

                  2.5  Bankruptcy.  Bankruptcy,  insolvency,  reorganization  or
liquidation proceedings or other proceedings for relief under any bankruptcy law
or any law for the  relief of debtors  shall be  instituted  by or  against  the
Borrower or any Significant Subsidiary of the Borrower;  provided, however, that
in the case of an involuntary  bankruptcy,  such  involuntary  bankruptcy  shall
continue undischarged or undismissed for a period of sixty (60) days;

                  2.6  Sale  of  Assets,   Merger.   The  sale,   conveyance  or
disposition  of all or  substantially  all of the assets of the  Borrower or the
consolidation, merger or other business combination of the Borrower with or into
any other  Person (as  defined  below) or Persons  when the  Borrower is not the
survivor.  "Person" shall mean any individual,  corporation,  limited  liability
company, partnership, association, trust or other entity or organization.



<PAGE>



                  IN WITNESS WHEREOF, Borrower has caused this Note to be signed
in its name by its duly authorized officer this 22nd day of October, 1999.


                               AURA SYSTEMS, INC.



                                    By:_____________________________________
                                      Name:
                                     Title:


ACKNOWLEDGED AND AGREED TO BY:


RGC INTERNATIONAL INVESTORS, LDC
By:      Rose Glen Capital Management, L.P., Investment Manager
         By:      RGC General Partner Corp., as General Partner


By: ______________________________
         Wayne D. Bloch
         Managing Director