Нreency Hz) Froык вку (Не) Time (s) Time (s) Frequency (Hz) Frequency (H) Time (s) Time(s) (a) One spectrogram. (b) Another spectrogram. Figure 1: Two spectrograms 1. Consider the spectrograms in Figs. la and lb. One of them represents the utterance of the word "Alexa," the other one the word "Siri.” For each utterance, there is one narrowband spectrogram and one wideband spectrogram.

(a) For each of the figures, is the top spectrogram wideband and the bottom spectrogram narrowband, or is it the other way around? Explain why.

(b) In Fig. la, consider the first phone being uttered. Is it a voiced or an unvoiced sound? Is is a fricative or a stop? Explain.

(c) Now look at the first phone in Fig. 1b. Is it voiced or unvoiced? Explain.

(d) In Fig. la, the second phone we encounter is likely a vowel. If you had to choose between /i/ and /u/, which would you choose and why?

(e) In conclusion, which of the spectrograms correspond to the utterance "Alexa" and which to "Siri" ? Explain.