Spectrograms: Being Acoustic Detectives

In the folder ‘Spectrograms’ under ‘Assignment 3’ on Blackboard are a series of spectrograms and waveforms of a nine-word utterance produced to 10,000 Hz. Each word comprises one syllable apart from word 5, which comprises two syllables. Where word boundaries are important, words have been clustered in the running speech spectrograms:
a. Whole utterance produced as running speech
b. Words 1 and 2 produced as running speech
c. Words 3 and 4 produced as running speech
d. Words 4 and 5 produced as running speech
e. Words 6 and 7 produced as running speech
f. Words 8 and 9 produced as running speech
g. Words 1 and 2 produced as a mechanical clock
h. Words 3 and 4 produced as a mechanical clock
i. Word 5 produced as a mechanical clock
j. Words 6 and 7 produced as a mechanical clock
k. Words 8 and 9 produced as a mechanical clock
The sentence resembles a newspaper headline and talks about a once rare bird now being very common in mid-summer.
Your task is threefold:

1. To work out as far as possible what is being said, using the evidence presented in the acoustic cues and with reference to materials and literature we have used in the module, plus other source material as necessary. You MUST contact me with your deductions and rationale before you go on to points 2 and 3, ideally before class in Week 12.
2. To write a brief commentary (c. 700 words) on the acoustic evidence to justify your deductions, integrating appropriate source material as necessary.
3. To produce a detailed phonetic transcription to facilitate your commentary discussion, based on the characteristics and acoustic cues you have highlighted on the spectrograms such as:
   • Voice bar
   • Amplitude and length features
   • Formant readings
   • Formant transitions
   • High frequency turbulence
   • VOT
   Go through the spectrograms systematically, highlighting acoustic evidence for:
   • Fricatives – how they compare in terms of duration, diffusion, frequency location, whether there is a voice bar etc.
   • Plosives – the presence of VOT, of a voice bar etc.
   • Vowels – compare F1, F2 of the different vowel qualities, including diphthongs
   • Approximants – if there are any, find the acoustic cues.
   • Think about CVC syllable structure and examine onsets and codas.
   • Write down all potential sounds for each feature in order to see what is possible and not possible lexically.

Sample Solution