Audio files for spectrum analysis demonstration

This data set consists of 6 real-world audio files (in .wav format, 48000Hz, mono) that are carefully crafted as examples for spectral analysis (i.e for teaching or as sample test data for algorithms).

The files have clear discernible sound with an added true random background ambient noise (composed of: distant fan noise + distant street traffic + close harddisk clicking noise). The sound is clearly discernible by a human, despite the noise. 

- There are some musical sounds (the note G3 on several instruments; fundamental frequency 196Hz) on a tubular bell, classical piano, trumpet, violin. The sounds of the instrument was generated from MIDI banks with FluidSynth software, played on a loudspeaker and re-recorded with an analogical microphone (with the ambient noises). Audio processing was performed with Tenacity software;

- Sample from human speech (wovel “o”), with the same processing as above; 

- The “Noise” file is purely digitally generated (white noise).

Each audio set is composed of three files: 

- The audio file (*.wav), each sampled at 48000 Hz, Mono. 

- an amplitude file (*_amplitude.csv, corresponding linear amplitudes recorded by the microphone of the .wav file). Numeric format in simple text format (.csv) with labeled column names. 

-a spectrum file (*_spectrum.csv, frequency/amplitude(dB) ) with the results of a FFT (Fast Fourier Transform). Numeric format in simple text format (.csv) with labeled column names. 

Detailed description of each set is provided below.

Bell_G3.wav

Bell_G3_amplitude.csv:Length processed: 113851 samples 2.37190 seconds.Sample Rate: 48000 Hz. Sample values on linear scale. 1 channel (mono).Length processed: 113851 samples, 2.37190 seconds.Peak amplitude: 0.59001 (linear) -4.58276 dB.  Unweighted RMS: -19.87796 dB.DC offset: 0.00069 linear, -63.18732 dB.

Bell_G3_spectrum.csv:FFT transform (Hz / dB)

Noise.wav

Noise_amplitude.csv:Length processed: 31765 samples 0.66177 seconds.Sample Rate: 48000 Hz. Sample values on linear scale. 1 channel (mono).Length processed: 31765 samples, 0.66177 seconds.Peak amplitude: 0.52797 (linear) -5.54788 dB.Unweighted RMS: -16.61153 dB.DC offset: -0.00013 linear, -77.53051 dB

Noise_spectrum.csv)FFT transform (Hz / dB)

Piano_G3.wav

Piano_G3_amplitude.csv:Sample Rate: 48000 Hz.Sample values on linear scale. 1 channel (mono).Length processed: 133063 samples, 2.77215 seconds.Peak amplitude: 0.41070 (linear) -7.72946 dB.Unweighted RMS: -23.95101 dB.DC offset: 0.00030 linear, -70.58058 dB.

Piano_G3_spectrum.csv:FFT transform (Hz / dB)

Trumpet_G3.wav

Trumpet_G3_amplitude.csv:Sample Rate: 48000 Hz.Sample values on linear scale. 1 channel (mono).Length processed: 66931 samples, 1.39440 seconds.Peak amplitude: 0.29551 (linear) -10.58853 dB.  Unweighted RMS: -22.00611 dB.DC offset: 0.00076 linear, -62.39740 dB.

Trumpet_G3_spectrum.csv:FFT transform (Hz / dB)

Violin_G3.wav

Violin_G3_amplitude.csv:Sample Rate: 48000 Hz.Sample values on linear scale. 1 channel (mono).Length processed: 59252 samples, 1.23442 seconds.Peak amplitude: 0.41633 (linear) -7.61119 dB.Unweighted RMS: -18.36738 dB.DC offset: 0.00021 linear, -73.46784 dB.

Violin_G3_spectrum.csv:FFT transform (Hz / dB)

Wovel_O.wav

Wovel_O_amplitude.csvSample Rate: 48000 Hz.Sample values on linear scale. 1 channel (mono).Length processed: 4975 samples, 0.10365 seconds.Peak amplitude: 0.46174 (linear) -6.71214 dB. Unweighted RMS: -14.88086 dB.DC offset: 0.00009 linear, -80.54917 dB.

Wovel_O_spectrum.csv:FFT transform (Hz / dB)

These files are created by A. Iftime and released under Creative Commons Licence, 2024. 

You might cite the dataset as: 

“Audio files for spectrum analysis demonstration” [dataset] (2024), in “Medical Biophysics for 1st year medical students”, by Călinescu O., Babeș R., Iftime A., Băran I., Ionescu D., Ganea C., in publishing