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                                  EXHIBIT 4.3

                              VOICETEX CORPORATION

                           1992 EQUITY INCENTIVE PLAN
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Section 1. Purpose
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     The purpose of the Voicetek Corporation 1992 Equity Incentive Plan (the
"Plan") is to attract and retain key employees and consultants to provide an
incentive for them to assist the Company to achieve long-range performance
goals and to enable them to participate in the long-term growth of the Company.

Section 2. Definitions
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     "Affiliate" means any business entity in which the Company owns directly
or indirectly 50% or more of the total combined voting power or has a
significant financial interest as determined by the Committee.

     "Award" means any Option, Stock Appreciation Right, Performance Share or
Restricted Stock awarded under the Plan.

     "Board" means the Board of Directors of the Company.

     "Code" means the Internal Revenue Code of 1986, as amended from time to
time.

     "Committee" means a committee of not less than three members of the Board
appointed by the Board to administer the Plan, provided that if and when the
Company is subject to Rule 16b-3 under the Securities Exchange Act of 1934, or
any successor provision ("Rule 16b-3"), each member of the Committee shall be a
"disinterested person" within the meaning of Rule 16b-3.

     "Common Stock" or "Stock" means the Common Stock, $.01 par value per
share, of the Company.

     "Company" means Voicetek Corporation.

     "Designated Beneficiary"  means the beneficiary designated by a
Participant, in a manner determined by the Committee, to receive amounts due or
exercise rights of the Participant in the event of the Participant's death. In
the absence of an effective designation by a Participant, Designated
Beneficiary shall mean the Participant's estate.

     "Fair Market Value" means, with respect to Common Stock or any other
property, the fair market value of such property as determined by the Committee
in good faith or in the manner established by the Committee from time to time.  
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     "Incentive Stock Option" means an option to purchase shares of Common
Stock awarded to a Participant under Section 6 which is intended to meet the
requirements of Section 422 of the Code or any successor provision.

     "Nonstatutory Stock Option" means an option to purchase shares of Common
Stock awarded to a Participant under Section 6 which is not intended to be an
Incentive Stock Option.

     "Option" means an Incentive Stock Option or a Nonstatutory Stock Option.

     "Participant" means a person selected by the Committee to receive an Award
under the Plan.

     "Performance Cycle" or "Cycle" means the period of time selected by the
Committee during which performance is measured for the purpose of determining
the extent to which an award of Performance Shares has been earned.

     "Performance Shares" mean shares of Common Stock which may be earned by
the achievement of performance goals awarded to a Participant under Section 8.

     "Reporting Person" means a person subject to Section 16 of the Securities
Exchange Act of 1934 or any successor provision.

     "Restricted Period" means the period of time selected by the Committee
during which an award of Restricted Stock may be forfeited to the Company.

     "Restricted Stock" means shares of Common Stock subject to forfeiture
awarded to a Participant under Section 9.

     "Stock Appreciation Right" or "SAR" means a right to receive any excess
in value of shares of Common Stock over the exercise price awarded to a
Participant under Section 7.


Section 3. Administration

     The Plan shall be administered by the Committee. The Committee shall have
authority to adopt, alter and repeal such administrative rules, guidelines and
practices governing the operation of the Plan as it shall from time to time
consider advisable, and to interpret the provisions of the Plan. The
Committee's decisions shall be final and binding. To the extent permitted by
applicable law, the Committee may delegate to one or more executive officers of
the Company the power to make Awards to Participants who are not Reporting
Persons and all determinations under the Plan with respect thereto, provided
that the Committee shall fix the maximum amount of such Awards for the group
and a maximum for any one Participant.


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Section 4. Eligibility
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     All employees (including part-time employees), and in the case of Awards
other than Incentive Stock Options, consultants of the Company or any Affiliate
capable of contributing significantly to the successful performance of the
Company, other than a person who has irrevocably elected not to be eligible,
are eligible to be Participants in the Plan.

Section 5. Stock Available for Awards
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     (a) Subject to adjustment under subsection (b) below, Awards may be made
under the Plan for up to 1,436,552 shares of Common Stock. If any Award in
respect of shares of Common Stock expires or is terminated unexercised or is
forfeited for any reason or settled in a manner that results in fewer shares
outstanding than were initially awarded, the shares subject to such Award or so
surrendered, as the case may be, to the extent of such expiration, termination,
forfeiture of decrease, shall again be available for award under the Plan,
subject, however, in the case of Incentive Stock Options, to any limitation
required under the Code. Common Stock issued through the assumption or
substitution of outstanding grants from an acquired company shall not reduce
the shares available for award under the Plan. Shares issued under the Plan may
consist in whole or in part of authorized but unissued shares or treasury
shares.

     (b) In the event that the Committee determines that any stock dividend,
extraordinary cash dividend, creation of a class of equity securities,
recapitalization, reorganization, merger, consolidation, split-up, spin-off,
combination, exchange of shares, warrants or rights offering to purchase Common
Stock at a price substantially below fair market value, or other similar
transaction affects the Common Stock such that an adjustment is required in
order to preserve the benefits or potential benefits intended to be made
available under the Plan, then the Committee, subject, in the case of Incentive
Stock Options, to any limitation required under the Code, shall equitably
adjust any or all of (i) the number and kind of shares in respect to which
Awards may be made under the Plan, (ii) the number and kind of shares subject
to outstanding Awards, and (iii) the award, exercise or conversion price with
respect to any of the foregoing, and if considered appropriate, the Committee
may make provision for a cash payment with respect to an outstanding Award,
provided that the number of shares subject to any Award shall always be a whole
number.

Section 6. Stock Options
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     (a) General
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          (i) Subject to the provisions of the Plan, the Committee may award
Incentive Stock Options and Nonstatutory Stock Options, and determine the
number of shares to be covered by each Option, the option price therefor and
the conditions and limitations applicable to the

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exercise of the Option. The terms and conditions of Incentive Stock Options
shall be subject to and comply with Section 422 of the Code, or any successor
provision, and any regulations thereunder. See subsection (b) below.

          (ii) The Committee shall establish the option price at the time each
option is awarded. In the case of Incentive Stock Options, such price shall not
be less than 100% of the Fair Market Value of the Common Stock on the date of
award. In the case of Nonstatutory Stock Options granted at a time when the
company is subject to Rule 16b-3, such price shall not be less than 50% of the
Fair Market Value of the Common Stock on the date of the award.

          (iii) Each Option shall be exercisable at such times and subject to
such terms and conditions as the Committee may specify in the applicable award
or thereafter. The Committee may impose such conditions with respect to the
exercise of Options, including conditions relating to applicable federal or
state securities laws, as it considers necessary or advisable.

          (iv) No shares shall be delivered pursuant to any exercise of an
Option until payment in full of the option price therefor is received by the
Company. Such payment may be made in whole or in part in cash or, to the extent
permitted by the Committee at or after the award of the Option, by delivery of
a note or shares of Common Stock owned by the optionee, including Restricted
Stock, valued at their Fair Market Value on the date of delivery, or such other
lawful consideration as the Committee may determine.

     (b)  Incentive Stock Options

          Options granted under the Plan which are intended to be Incentive
Stock Options shall be subject to the following additional terms and conditions:

          (i)  All Incentive Stock Options granted under the Plan shall, at the
time of grant, be specifically designated as such in the option agreement
covering such Incentive Stock Options. The Option exercise period shall not
exceed ten years from the date of grant.

          (ii) If any employee to whom an Incentive Stock Option is to be
granted under the Plan is, at the time of the grant of such option, the owner
of stock possessing more than 10% of the total combined voting power of all
classes of stock of the company (after taking into account the attribution of
stock ownership rules of Section 424(d) of the Code), then the following
special provisions shall be applicable to the Incentive Stock Option granted to
such individual:

               (x)  The purchase price per share of the Common Stock subject to
          such Incentive Stock Option shall not be less than 110% of the Fair
          Market Value of one share of Common Stock at the time of grant; and


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               (y)  The option exercise period shall not exceed five years from
          the date of grant.

         (iii) For so long as the Code shall so provide, options granted to any 
employee under the Plan (and any other incentive stock option plans of the
Company) which are intended to constitute Incentive Stock Options shall not
constitute Incentive Stock Options to the extent that such options, in the
aggregate, become exercisable for the first time in any one calendar year for
shares of Common Stock with an aggregate Fair Market Value (determined as of
the respective date or dates of grant) of more than $100,000.

          (iv) No Incentive Stock Option may be exercised unless, at the time
of such exercise, the Participant is, and has been continuously since the date
of grant of his or her option, employed by the Company, except that:

               (x)  an Incentive Stock Option may be exercised within the
period of three months after the date the Participant ceases to be an employee
of the Company (or within such lesser period as may be specified in the
applicable option agreement), PROVIDED, that the agreement with respect to such
Option may designate a longer exercise period and that the exercise after such
three-month period shall be treated as the exercise of a Nonstatutory Stock
Option under the Plan;

               (y)  if the Participant dies while in the employ of the company,
or within three months after the participant ceases to be such an employee, the
Incentive Stock Option may be exercised by the Participant's Designated
Beneficiary within the period of one year after the date of death (or within
such lesser period as may be specified in the applicable option agreement); and

               (z)  if the participant becomes disabled (within the meaning of
Section 22(e)(3) of the Code or any successor provision thereto) while in the
employ of the Company, the Incentive Stock Option may be exercised within the
period of one year after the date the Participant ceases to be such an employee
because of such disability (or within such lesser period as may be specified in
the applicable option agreement).

For all purposes of the Plan and any Option granted hereunder, "employment"
shall be defined in accordance with the provisions of Section 1.421-7(h) of the
Income Tax Regulations (or any successor regulations). Notwithstanding the
foregoing provisions, no Incentive Stock Option may be exercised after its
expiration date.


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Section 7. Stock Appreciation Rights

     (a)  Subject to the provisions of the Plan, the Committee may award SARs in
tandem with an Option (at or after the award of the Option), or alone and
unrelated to an Option. SARs in tandem with an Option shall terminate to the
extent that the related Option is exercised, and the related Option shall
terminate to the extent that the tandem SARs are exercised. SARs granted in
tandem with Options shall have an exercise price of not less than the exercise
price of the related Option. SARs granted at a time when the Company is subject
to Rule 16b-3 shall have an exercise price of not less than 50% of the Fair
Market Value of the Common Stock on the date of award, or in the case of SARs
granted in tandem with Options, the exercise price of the SAR shall not be less
than the exercise price of the related Option.

     (b)  An SAR related to an Option which can only be exercised during
limited periods following a change in control of the Company may entitle the
Participant to receive an amount based upon the highest price paid or offered
for Common Stock in any transaction relating to the change in control or paid
during the thirty-day period immediately preceding the occurrence of the change
in control in any transaction reported in any stock market in which the Common
Stock is usually traded.

Section 8. Performance Shares

     (a)  Subject to the provisions of the Plan, the Committee may award
Performance Shares and determine the number of such shares for each Performance
Cycle and the duration of each Performance Cycle. There may be more than one
Performance Cycle in existence at any one time, and the duration of
Performance  Cycles may differ from each other. The payment value of
Performance Shares shall be equal to the Fair Market Value of the Common Stock
on the date the Performance Shares are earned or, in the discretion of the
Committee, on the date the committee determines that the Performance Shares
have been earned.

     (b)  The Committee shall establish performance goals for each Cycle, for
the purpose of determining the extent to which Performance Shares awarded for
such Cycle are earned, on the basis of such criteria and to accomplish such
objectives as the Committee may from time to time select. During any Cycle, the
Committee may adjust the performance goals for such Cycle as it deems equitable
in recognition of unusual or non-recurring events affecting the Company,
changes in applicable tax laws or accounting principles, or such other factors
as the Committee may determine.

     (c)  As soon as practicable after the end of a Performance Cycle, the
Committee shall determine the number of Performance Shares which have been
earned on the basis of performance in relation to the established performance
goals. The payment values of earned Performance Shares shall be distributed to
the Participant or, if the Participant has died, to the Participant's
Designated Beneficiary, as soon as practicable thereafter. The Committee shall


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determine, at or after the time of award, whether payment values will be
settled in whole or in part in cash or other property, including Common Stock
or Awards.

Section 9.  Restricted Stock
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     (a)  Subject to the provisions of the Plan, the Committee may award shares
of Restricted Stock and determine the duration of the Restricted Period during
which, and the conditions under which, the shares may be forfeited to the
Company and the other terms and conditions of such Awards. Shares of Restricted
Stock shall be issued for no cash consideration or such minimum consideration
as may be required by applicable law.

     (b)  Shares of Restricted Stock may not be sold, assigned, transferred,
pledged or otherwise encumbered, except as permitted by the Committee, during
the Restricted Period. Shares of Restricted Stock shall be evidenced in such
manner as the Committee may determine. Any certificates issued in respect of
shares of Restricted Stock shall be registered in the name of the Participant
and unless otherwise determined by the Committee, deposited by the Participant,
together with a stock power endorsed in blank, with the Company. At the
expiration of the Restricted Period, the Company shall deliver such
certificates to the Participant or if the Participant has died, to the
Participant's Designated Beneficiary.

Section 10.  General Provisions Applicable to Awards
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     (a)  APPLICABILITY OF RULE 16b-3. Those provisions of the Plan which make
an express reference to Rule 16b-3 shall apply to the Company only at such
time as the Company's Common Stock is registered under the Securities Exchange
Act of 1934, or any successor provision, and then only to Reporting Persons.

     (b)  REPORTING PERSON LIMITATIONS. Notwithstanding any other provision of
the Plan, to the extent required to qualify for the exemption provided by Rule
16b-3 under the Securities Exchange Act of 1934, and any successor provision,
(i) any Common Stock or other equity security offered under the Plan to a
Reporting Person may not be sold for at least six months after acquisition, or,
in the case of an Option or SAR, at least six months elapse between the date of
grant of the Option or the SAR and the date of disposition of the Option or SAR
or the Common Stock acquired under the Option, except in case of death or
disability and (ii) any Option, SAR or other similar right related to an equity
security issued under the Plan to a Reporting Person shall not be transferrable
other than by will or the laws of descent and distribution or pursuant to a
qualified domestic relations order as defined by the Code or Title I of the
Employee Retirement Income Security Act ("ERISA"), or the rules thereunder,
shall not be exercisable for at least six months except in the case of death or
disability and shall be exercisable during the Participant's lifetime only by
the Participant or the Participant's guardian or legal representative.

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      (c)   DOCUMENTATION. Each Award under the Plan shall be evidenced by a
writing delivered to the Participant specifying the terms and conditions
thereof and containing such other terms and conditions not inconsistent with
the provisions of the Plan as the Committee considers necessary or advisable
to achieve the purposes of the Plan or comply with applicable tax and
regulatory laws and accounting principles.

      (d)   COMMITTEE DISCRETION. Each type of Award may be made alone, in
addition to or in relation to any other type of Award. The terms of each type
of Award need not be identical, and the Committee need not treat Participants
uniformly. Except as otherwise provided by the Plan or a particular Award, any
determination with respect to an Award may be made by the Committee at the time
of award or at any time thereafter.

      (e)   SETTLEMENT. The Committee shall determine whether Awards are
settled in whole or in part in cash, Common Stock, other securities of the
Company, Awards or other property. The Committee may permit a Participant to
defer all or any portion of a payment under the Plan, including the crediting
of interest on deferred amounts denominated in cash and dividend equivalents on
amounts denominated in Common Stock.

      (f)   DIVIDENDS AND CASH AWARDS. In the discretion of the Committee, any
Award under the Plan may provide the Participant with (i) dividends or dividend
equivalents payable currently or deferred with or without interest, and (ii)
cash payments in lieu of or in addition to an Award.

      (g)   TERMINATION OF EMPLOYMENT. The Committee shall determine the effect
on an Award of the disability, death, retirement or other termination of
employment of a Participant and the extent to which, and the period during
which, the Participant's legal representative, guardian or Designated
Beneficiary may receive payment of an Award or exercise rights thereunder.

      (h)   CHANGE IN CONTROL. In order to preserve a Participant's rights
under an Award in the event of a change in control of the Company, the
Committee in its discretion may, at the time an Award is made or at any time
thereafter, take one or more of the following actions: (i) provide for the
acceleration of any time period relating to the exercise or realization of the
Award, (ii) provide for the purchase of the Award upon the Participant's
request for an amount of cash or other property that could have been received
upon the exercise or realization of the Award had the Award been currently
exercisable or payable, (iii) adjust the terms of the Award in a manner
determined by the Committee to reflect the change in control, (iv) cause the
Award to be assumed, or new rights substituted therefor, by another entity, or
(v) make such other provision as the Committee may consider equitable and in
the best interests of the Company.

      (i)   WITHHOLDING. The Participant shall pay to the Company, or make
provision satisfactory to the Committee for payment of, any taxes required by
law to be withheld in respect of Awards under the Plan no later than the date
of the event creating the tax liability. In the Committee's discretion, such
tax obligations may be paid in whole or in part in shares of 


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Common Stock, including shares retained from the Award creating the tax
obligation, valued at their Fair Market Value on the date of delivery. The
Company and its Affiliates may, to the extent permitted by law, deduct any
such tax obligations from any payment of any kind otherwise due to the
Participant.

     (j) FOREIGN NATIONALS. Awards may be made to Participants who are foreign
nationals or employed outside the United States on such terms and conditions
different from those specified in the Plan as the Committee considers necessary
or advisable to achieve the purposes of the Plan or comply with applicable laws.

     (k) AMENDMENT OF AWARD. The Committee may amend, modify or terminate any
outstanding Award, including substituting therefor another Award of the same or
a different type, changing the date of exercise or realization and converting
an Incentive Stock Option to a Nonstatutory Stock Option, provided that the
Participant's consent to such action shall be required unless the Committee
determines that the action, taking into account any related action, would not
materially and adversely affect the Participant.

Section 11. Miscellaneous
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     (a) NO RIGHT TO EMPLOYMENT. No person shall have any claim or right to be
granted an Award, and the grant of an Award shall not be construed as giving a
Participant the right to continued employment. The Company expressly reserves
the right at any time to dismiss a Participant free from any liability or claim
under the Plan; except as expressly provided in the applicable Award.

     (b) NO RIGHTS AS SHAREHOLDER. Subject to the provisions of the applicable
Award, no Participant or Designated Beneficiary shall have any rights as a
shareholder with respect to any shares of Common Stock to be distributed under
the Plan until he or she becomes the holder thereof. A participant to whom
Common Stock is awarded shall be considered the holder of the Stock at the time
of the Award except as otherwise provided in the applicable Award.

     (c) EFFECTIVE DATE. Subject to the approval of the shareholders of the
Company, the Plan shall be effective on May 21, 1992. Prior to such approval,
Awards may be made under the Plan expressly subject to such approval.

     (d) AMENDMENT OF PLAN. The Board may amend, suspend or terminate the Plan
or any portion thereof at any time, provided that no amendment shall be made
without shareholder approval if such approval is necessary to comply with any
applicable tax or regulatory requirement, including any requirement for
exemptive relief under Section 16(b) of the Securities Exchange Act of 1934, or
any successor provision. Prior to any such approval, Awards may be made under
the Plan expressly subject to such approval.

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          (e) GOVERNING LAW. The provisions of the Plan shall be governed by
and interpreted in accordance with the laws of the Commonwealth of
Massachusetts.


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