Avaya 03-300430 User Manual

The TN725B Speech Synthesis circuit pack provides four independent Speech Synthesis ports 
which may be connected to any of the voice time slots on the Time Division Multiplex (TDM) 
Bus. Each Speech Synthesis port consists of a speech synthesizer device (SSD) and is 
managed by a custom-coded programmable speech synthesizer (PSS) controller. The PSS 
controller is, in turn, controlled by the on-board microprocessor via a command interface 
specifically designed for this application. The PSS controller’s main function is the orderly 
transfer of encoded speech from the speech vocabulary read-only memory (ROM) to the SSDs. 
The SSDs decode it and produce 64-kbps 5-255 PCM (Pulse Code Modulation) speech. The 
encoded speech is stored in up to 512 Kbytes of on-board ROM. In addition, each Speech 
Synthesis port has an associated dual-tone multifrequency receiver (DTMR) to receive 
touch-tone digits from a station set connected to the port via a voice time slot. The station set 
may be connected to the Speech Synthesis port through either a line or trunk circuit.
When there is an incoming call to a port, the “listen” network time slot is connected to the DTMF 
receiver input and the “talk” network time slot is connected to the SSD output. This enables the 
Speech Synthesis port to support speech synthesis features or touch-tone input with voice 
response features. Some of the features that use the Speech Synthesis port’s capabilities 
include Leave Word Calling, Automatic Circuit Assurance, Automatic Wakeup (hotel-motel), and 
Do Not Disturb (hotel-motel).
The Speech Synthesis circuit pack supports different voice features than ones supported by the 
Announcement circuit pack.

S-SYN-PT

MAJ

test port location sh

Speech Synthesis port

S-SYN-PT

MIN

test port location l

Speech Synthesis port

S-SYN-PT

WRN

test port location sh

Speech Synthesis port

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0

Any

Any

Any

test port location sh r 1

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17672

None

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