Relevant Acoustic Phonetics of L2 English

Focus on Intelligibility

Ettien Koffi

• Publisher: CRC Press
• Year: 2021
• ISBN:
  9781000340099
• Edition: 1
• Topic: Languages & Linguistics
• Subtopic: Phonetics & Phonology
• Index: Languages & Linguistics

Intelligibility is the ultimate goal of human communication. However, measuring it objectively remained elusive until the 1940s when physicist Harvey Fletcher pioneered a psychoacoustic methodology for doing so. Another physicist, von Bekesy, demonstrated clinically that Fletcher's theory of Critical Bands was anchored in anatomical and auditory reality. Fletcher's and Bekesy's approach to intelligibility has revolutionized contemporary understanding of the processes involved in encoding and decoding speech signals. Their insights are applied in this book to account for the intelligibility of the pronunciation of 67 non-native speakers from the following language backgrounds –10 Arabic, 10 Japanese, 10 Korean, 10 Mandarin, 11 Serbian and Croatian "the Slavic Group, " 6 Somali, and 10 Spanish speakers who read the Speech Accent Archive elicitation paragraph. Their pronunciation is analyzed instrumentally and compared and contrasted with that of 10 native speakers of General American English (GAE) who read the same paragraph. The data-driven intelligibility analyses proposed in this book help answer the following questions:

• Can L2 speakers of English whose native language lacks a segment/segments or a suprasegment/ suprasegments manage to produce it/them intelligibly?

• If they cannot, what segments or suprasegments do they use to substitute for it/them?

• Do the compensatory strategies used interfere with intelligibility?

The findings reported in this book are based on nearly 12, 000 measured speech tokens produced by all the participants. This includes some 2, 000 vowels, more than 500 stop consonants, over 3, 000 fricatives, nearly 1, 200 nasals, about 1, 500 approximants, a over 1, 200 syllables onsets, as many as 800 syllable codas, more than 1, 600 measurement of F0/pitch, and duration measurements of no fewer than 539 disyllabic words. These measurements are in keeping with Baken and Orlikoff (2000: 3) and in accordance with widely accepted Just Noticeable Difference thresholds, and relative functional load calculations provided by Catforda (1987).

CHAPTER 1
Review and Preview of Essential Concepts

---

Review and Preview of Essential Concepts - serves as a review and a preview of essential linguistic concepts that are used in this book. This approach allows readers with no prior exposure to linguistics to be on the same page with those who have had an introductory course. Terminology related to the phonetic classification of segments is discussed and illustrated. Consonants are categorized according three intrinsic features: voicing, place of articulation, and manner of articulation. The features for vowels vary from three to five: height (aperture), horizontal tongue movements (front, central, back), and lip (rounded vs. unrounded), tongue root advancement or retraction, and nasality. The chapter (re)familiarizes the reader with the IPA symbols used to transcribe English phonetically. It also contains tables that list English phonemes, their main allophones, and their frequency of occurrence. A brief discussion of the syllable is presented. The nomenclature for classifying syllables into various types is introduced, along with an illustrative syllable diagram. This chapter is a perfect segue into the rest of the book where the same concepts are revisited and expanded.

1.0 Introduction

This chapter seeks to accomplish two objectives. It is meant as a comprehensive review of the phonetics and phonology sections that are covered in most introduction to linguistics textbooks. This chapter also doubles as a preview/overview because it touches on all the concepts that will be elaborated on in subsequent chapters. The topics discussed in this chapter are the following:

1. The overview of acoustic phonetics and speech intelligibility;

2. The description of the overall architecture of speech;

3. The deconstruction of speech sounds into bundles of phonetic features;

4. The structure and definition of syllables and related terms;

5. The overview of the principles of phonetic transcription.

1.1 A Quick Overview of Acoustic Phonetics

In contemporary linguistics, it is customary to separate phonetics from phonology and to treat them as two separate sub-disciplines. We will go along with this classification; but phonetics, more precisely, acoustic phonetics, is subdivided into three subfields, as represented by Figure 1-1:

Figure 1-1: Sub-branches of Acoustic Phonetics.

Speech production deals with how speech sounds are produced by human speech organs. The main articulators are the larynx (vocal folds), the oral cavity, the nasal cavity, the tongue, the lips, and the teeth. Stone and Shadle (2016:48) propose the following expansive definition of speech production:

We think of “speech” as an acoustic signal that is heard when people talk to each other. But that sound is the end result of a complex process, starting in the brain where thoughts are translated into language and muscle commands are sent to our vocal tract to shape it and get air moving through it. As the air moves through the slowly changing vocal tract, the right sounds will be produced in the right sequence so that they can be interpreted by the listener as speech. Once the muscles are activated, production is in progress and the physical properties of aerodynamics take over to produce a particular acoustic waveform.

Speech production experts are now using ultrasound technology, laryngoscopy, and vocal tract visualization techniques to show with greater accuracy than ever before what speakers do with their speech organs when they produce individual sounds. Ultrasounds and other investigative tools are expensive and not widely available. However, it is expected that prices will go down soon and that even linguistic programs with modest budgets will be able to afford them. A flurry of recent presentations at the Acoustical Society of America meetings is indication of an ever-increasing use of ultrasound technology in speech production research.

Speech perception encompasses a vast area that extends from the auditory processing of speech signals and the transduction mechanisms that lead to neurolinguistic processing, and ultimately to speech comprehension. Speech perception experts study how air molecules go into the ear canal, travel through the middle ear, the inner ear, and continue further until the acoustic signals are transformed into recognizable phones, phonemes, syllables, morphemes, and eventually ...