{"description":"Test your understanding of audio signal processing, FFT, spectrograms, and their role in machine learning.","questions":[{"answer":"Converts audio from time domain to frequency domain","number":1,"options":["Compresses audio files","Converts audio from time domain to frequency domain","Increases audio volume","Eliminates echo from audio signals"],"question":"What does the Fast Fourier Transform (FFT) do in audio processing?"},{"answer":"Frequency content of a signal over time","number":2,"options":["Volume of audio over time","Frequency content of a signal over time","Compression ratio of audio files","Amplitude of a video signal"],"question":"What does a spectrogram visualize?"},{"answer":"Short-Time Fourier Transform (STFT)","number":3,"options":["Fast Wavelet Transform","Short-Time Fourier Transform (STFT)","Discrete Cosine Transform","Laplacian Transform"],"question":"Which transform is typically used to generate a spectrogram?"},{"answer":"Time","number":4,"options":["Frequency","Amplitude","Time","Phase"],"question":"What does the x-axis represent in a typical spectrogram?"},{"answer":"Presence of a frequency with high amplitude","number":5,"options":["A drop in signal volume","A sudden change in phase","Presence of a frequency with high amplitude","Data loss in transmission"],"question":"What does a peak in an FFT magnitude plot indicate?"},{"answer":"It balances time and frequency resolution","number":6,"options":["It determines audio volume","It controls bit rate for compression","It balances time and frequency resolution","It adjusts pitch of the signal"],"question":"Why is frame size important in FFT analysis?"},{"answer":"Sampling it into digital form","number":7,"options":["Amplifying the signal","Removing silence","Sampling it into digital form","Reversing the signal"],"question":"What is typically the first step in processing an analog audio signal for machine learning?"},{"answer":"Greater amplitude at that frequency and time","number":8,"options":["High pitch","Low frequency","Greater amplitude at that frequency and time","Noise cancellation"],"question":"What does a high color intensity in a spectrogram represent?"},{"answer":"It helps distinguish phonemes based on frequency","number":9,"options":["It compresses the audio files","It identifies language","It helps distinguish phonemes based on frequency","It removes speaker accents"],"question":"Why is FFT useful in speech recognition?"},{"answer":"It has lower computational complexity (faster)","number":10,"options":["It works only on analog signals","It requires less memory","It has lower computational complexity (faster)","It uses real numbers only"],"question":"What is a key advantage of FFT over traditional DFT?"}],"title":"Audio Basics"}