Explain the job of the analogue-to-digital converter in a voice recognition system.

The analogue-to-digital converter samples the microphone's continuous waveform many thousands of times a second and records each sample as a binary number, producing the digital signal the recogniser works on.

State a typical sampling rate for speech recognition and explain the trade-off in raising it.

Speech for recognition is commonly sampled at about 16 000 samples per second, and a higher rate captures more detail of consonants at the cost of more data to store and process.

Define the term phoneme.

A phoneme is the smallest unit of sound that distinguishes one word from another in a language, and a recogniser identifies a sequence of phonemes before assembling them into words.

What is an acoustic model?

An acoustic model stores the range of sound patterns that correspond to each phoneme, built from recordings of many speakers, and it is what allows an incoming sound to be matched to a phoneme.

CCEA A-Level Digital Technology 2650

Systems Analysis and Development Approaches

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Artificial Intelligence, Expert Systems and Robotics

Voice recognition technology

3 things to know
A2 Unit 1

Overview

Voice recognition, term phoneme and acoustic model.

What you need to know

Answer each one before you reveal it.

Your recallNot started

Key term

Describe the hardware a voice recognition system requires.

Key term

Explain why accents and homophones cause recognition errors.

Key term

What is voice recognition?

Questions from this subtopic

Each one with the model answer underneath.

1
What is voice recognition?
Model answer
Voice recognition is the conversion of spoken words into text or into commands a computer can act on, by matching the sound pattern of the speech against models of how words are pronounced.
2
Describe the hardware a voice recognition system requires.
Model answer
Voice recognition needs a microphone to capture the sound, an analogue-to-digital converter to sample it, a processor fast enough to analyse the samples as they arrive, and storage for the acoustic and language models.
3
Explain the job of the analogue-to-digital converter in a voice recognition system.
Model answer
The analogue-to-digital converter samples the microphone's continuous waveform many thousands of times a second and records each sample as a binary number, producing the digital signal the recogniser works on.
4
State a typical sampling rate for speech recognition and explain the trade-off in raising it.
Model answer
Speech for recognition is commonly sampled at about 16 000 samples per second, and a higher rate captures more detail of consonants at the cost of more data to store and process.
5
Define the term phoneme.
Model answer
A phoneme is the smallest unit of sound that distinguishes one word from another in a language, and a recogniser identifies a sequence of phonemes before assembling them into words.
6
What is an acoustic model?
Model answer
An acoustic model stores the range of sound patterns that correspond to each phoneme, built from recordings of many speakers, and it is what allows an incoming sound to be matched to a phoneme.

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