EXAM STUDY GUIDE

What is speech degradation?

1. Adding noise-Whenever there are other sources making sounds during a conversation, all of the sounds - including the speech we are listening to - mix together. 2. Speech Degradation #2: Noise Vocoding (Simulation of Speech through a Cochlear Implant)-We can take speech and process it so that it matches some of the characteristics of a cochlear implant signal. 3. Speech Degradation #3: Sine Wave Speech- replace the formants with tones varying in frequency. This preserves the amplitude envelope and the spectral envelope, but the harmonics will be gone completely.

What are the principles of ASA?

1. Similarity: likely to be from the same sound source if more similar. 2. Closure: a continuous sound briefly interrupted is likely to be continuous. 3. Belongingness: unlikely that a single component originates from two different sources simultaneously. 4. Figure-Ground: segregating the auditory world into the event that we are attending to from the background "noise."

What are the 2 binaural cues of sound localization?

1. interaural level differences- The differences in sound pressure level reaching the two ears. Reduction in intensity occurs for high frequency sounds for the far ear. 2. interaural time differences-The difference between the times that sounds reach the two ears.

What is amplitude? What is the perceptual correlate?

Amplitude is the size of the pressure changes, and it is a physical measure. The perceptual correlate is loudness.

What is articulation?

Articulation is responsible for creating filter for speech, by changing the shape of the vocal trap (manipulating the articulators) shapes of filters the sound created by the vocal folds.

What are egressive VS. ingressive speech sounds?

Egressive sounds are sounds in which the air stream is created by pushing air out through the mouth or nose. The opposite of an egressive sound is an ingressive sound, in which the airstream flows inward through the mouth or nose.

What are formants?

Formants are resonances of the vocal tract

What is frequency? What is the perceptual correlate?

Frequency is the number of cycles/waves within a given amount of time. The perceptual correlate is pitch; high frequency=high pitch.

What are harmonics?

Harmonics are multiples of the fundamental frequency.

What is fundamental frequency?

It is the first line of any spectrum. It is associated with our perception of pitch-which creates differences in voices.

What is melody?

Melody is the succession of relative pitches played in particular order; common in most music.

What is phase? What is the perceptual correlate?

Phase is the portion of the cycle through which the wave has advanced in relation to some fixed point in time. There is no perceptual correlate to phase.

What is phonation?

Phonation is the source of speech, what starts vibration for sound, related to rate of vibration of vocal folds.

What is pitch?

Pitch is the perceptual quality that we give to frequency. It cannot be measured in a physical way, and is associated with the fundamental frequency.

What is a spectrum?

Represents Amplitude x Frequency

What is a waveform?

Represents Amplitude x Time

What is a spectrogram?

Represents Frequency x Time (by Amplitude)

What are resonances? How are they created? How do we see them on a spectrum? How are they related to timbre?

Resonances are "preferred" vibrating frequencies, the system was designed to vibrate at those frequencies. Resonances are responsible for the differences in pattern of amplitudes of the harmonics and our perception of an instrument's timbre.

How does the concept of the source and filter relate to the instrument of your choice?

The source is the object that vibrate-giving us our sound. The filter is what actually gives us the quality or the timbre that we perceive. The different in sound between instruments playing the same note is due to the difference in the amplitude of the harmonics.

What is "lack of invariance?" What is one source of variability within the speech signal?

There is no simple relationship between a particular phoneme and the acoustic signal. 4 causes of variability are: 1. Influence of native language 2. Talker variability 3. Context effects 4. Influence of visual context

What is timbre?

Timbre is the identity of an instrument. It is a perception related to the pattern of amplitudes across harmonics.

What are phonemes?

phonemes are the smallest sounds in a spoken word. The changing of a phoneme can change the meaning of a word.