9. A speech producing apparatus as claimed in claim 8, wherein: said control means further includes a secondary accent pitch pattern assignment means for assigning to the first secondary accent syllable a pitch pattern moderately rising in frequency if said first secondary accent syllable occurs prior to the primary accent syllable and for assigning to subsequent secondary accent syllables a pitch pattern generally stable in frequency if said subsequent secondary accent syllable occurs prior to the primary accent syllable.
10. A speech producing apparatus as claimed in claim 9, wherein: said control means further includes an unstressed syllable pitch pattern assignment means for assigning to unstressed syllables a pitch pattern slightly falling in frequency except if when the unstressed syllable is immediately following the first secondary accent syllable whereupon a pitch pattern generally stable in frequency at an elevated frequency is assigned to the unstressed syllable.