diff --git a/chirp_instantaneous_freq/filters.py b/chirp_instantaneous_freq/filters.py
new file mode 100644
index 0000000..709b140
--- /dev/null
+++ b/chirp_instantaneous_freq/filters.py
@@ -0,0 +1,202 @@
+from scipy.signal import butter, sosfiltfilt
+from scipy.ndimage import gaussian_filter1d
+import numpy as np
+
+
+def instantaneous_frequency(
+    signal: np.ndarray,
+    samplerate: int,
+    smoothing_window: int,
+) -> tuple[np.ndarray, np.ndarray]:
+    """
+    Compute the instantaneous frequency of a signal that is approximately
+    sinusoidal and symmetric around 0.
+
+    Parameters
+    ----------
+    signal : np.ndarray
+        Signal to compute the instantaneous frequency from.
+    samplerate : int
+        Samplerate of the signal.
+    smoothing_window : int
+        Window size for the gaussian filter.
+
+    Returns
+    -------
+    tuple[np.ndarray, np.ndarray]
+
+    """
+    # calculate instantaneous frequency with zero crossings
+    roll_signal = np.roll(signal, shift=1)
+    time_signal = np.arange(len(signal)) / samplerate
+    period_index = np.arange(len(signal))[(roll_signal < 0) & (signal >= 0)][
+        1:-1
+    ]
+
+    upper_bound = np.abs(signal[period_index])
+    lower_bound = np.abs(signal[period_index - 1])
+    upper_time = np.abs(time_signal[period_index])
+    lower_time = np.abs(time_signal[period_index - 1])
+
+    # create ratio
+    lower_ratio = lower_bound / (lower_bound + upper_bound)
+
+    # appy to time delta
+    time_delta = upper_time - lower_time
+    true_zero = lower_time + lower_ratio * time_delta
+
+    # create new time array
+    instantaneous_frequency_time = true_zero[:-1] + 0.5 * np.diff(true_zero)
+
+    # compute frequency
+    instantaneous_frequency = gaussian_filter1d(
+        1 / np.diff(true_zero), smoothing_window
+    )
+
+    return instantaneous_frequency_time, instantaneous_frequency
+
+
+def inst_freq(signal, fs):
+    """
+    Computes the instantaneous frequency of a periodic signal using zero-crossings.
+    
+    Parameters:
+    -----------
+    signal : array-like
+        The input signal.
+    fs : float
+        The sampling frequency of the input signal.
+    
+    Returns:
+    --------
+    freq : array-like
+        The instantaneous frequency of the input signal.
+    """
+    # Compute the sign of the signal
+    sign = np.sign(signal)
+    
+    # Compute the crossings of the sign signal with a zero line
+    crossings = np.where(np.diff(sign))[0]
+    
+    # Compute the time differences between zero crossings
+    dt = np.diff(crossings) / fs
+    
+    # Compute the instantaneous frequency as the reciprocal of the time differences
+    freq = 1 / dt
+
+    # Gaussian filter the signal 
+    freq = gaussian_filter1d(freq, 10)
+    
+    # Pad the frequency vector with zeros to match the length of the input signal
+    freq = np.pad(freq, (0, len(signal) - len(freq)))
+    
+    return freq
+
+def bandpass_filter(
+        signal: np.ndarray,
+        samplerate: float,
+        lowf: float,
+        highf: float,
+) -> np.ndarray:
+    """Bandpass filter a signal.
+
+    Parameters
+    ----------
+    signal : np.ndarray
+        The data to be filtered
+    rate : float
+        The sampling rate
+    lowf : float
+        The low cutoff frequency
+    highf : float
+        The high cutoff frequency
+
+    Returns
+    -------
+    np.ndarray
+        The filtered data
+    """
+    sos = butter(2, (lowf, highf), "bandpass", fs=samplerate, output="sos")
+    filtered_signal = sosfiltfilt(sos, signal)
+
+    return filtered_signal
+
+
+def highpass_filter(
+    signal: np.ndarray,
+    samplerate: float,
+    cutoff: float,
+) -> np.ndarray:
+    """Highpass filter a signal.
+
+    Parameters
+    ----------
+    signal : np.ndarray
+        The data to be filtered
+    rate : float
+        The sampling rate
+    cutoff : float
+        The cutoff frequency
+
+    Returns
+    -------
+    np.ndarray
+        The filtered data
+    """
+    sos = butter(2, cutoff, "highpass", fs=samplerate, output="sos")
+    filtered_signal = sosfiltfilt(sos, signal)
+
+    return filtered_signal
+
+
+def lowpass_filter(
+    signal: np.ndarray,
+    samplerate: float,
+    cutoff: float
+) -> np.ndarray:
+    """Lowpass filter a signal.
+
+    Parameters
+    ----------
+    data : np.ndarray
+        The data to be filtered
+    rate : float
+        The sampling rate
+    cutoff : float
+        The cutoff frequency
+
+    Returns
+    -------
+    np.ndarray
+        The filtered data
+    """
+    sos = butter(2, cutoff, "lowpass", fs=samplerate, output="sos")
+    filtered_signal = sosfiltfilt(sos, signal)
+
+    return filtered_signal
+
+
+def envelope(signal: np.ndarray,
+             samplerate: float,
+             cutoff_frequency: float
+             ) -> np.ndarray:
+    """Calculate the envelope of a signal using a lowpass filter.
+
+    Parameters
+    ----------
+    signal : np.ndarray
+        The signal to calculate the envelope of
+    samplingrate : float
+        The sampling rate of the signal
+    cutoff_frequency : float
+        The cutoff frequency of the lowpass filter
+
+    Returns
+    -------
+    np.ndarray
+        The envelope of the signal
+    """
+    sos = butter(2, cutoff_frequency, "lowpass", fs=samplerate, output="sos")
+    envelope = np.sqrt(2) * sosfiltfilt(sos, np.abs(signal))
+
+    return envelope
diff --git a/chirp_instantaneous_freq/fish_signal.py b/chirp_instantaneous_freq/fish_signal.py
new file mode 100644
index 0000000..bf740b6
--- /dev/null
+++ b/chirp_instantaneous_freq/fish_signal.py
@@ -0,0 +1,557 @@
+import sys
+from IPython import embed
+import thunderfish.powerspectrum as ps
+import numpy as np
+
+species_name = dict(
+    Sine="Sinewave",
+    Alepto="Apteronotus leptorhynchus",
+    Arostratus="Apteronotus rostratus",
+    Eigenmannia="Eigenmannia spec.",
+    Sternarchella="Sternarchella terminalis",
+    Sternopygus="Sternopygus dariensis",
+)
+"""Translate species ids used by wavefish_harmonics and pulsefish_eodpeaks to full species names.
+"""
+
+
+def abbrv_genus(name):
+    """Abbreviate genus in a species name.
+
+    Parameters
+    ----------
+    name: string
+        Full species name of the form 'Genus species subspecies'
+
+    Returns
+    -------
+    name: string
+        The species name with abbreviated genus, i.e. 'G. species subspecies'
+    """
+    ns = name.split()
+    return ns[0][0] + ". " + " ".join(ns[1:])
+
+
+# Amplitudes and phases of various wavefish species:
+
+Sine_harmonics = dict(amplitudes=(1.0,), phases=(0.5 * np.pi,))
+
+Apteronotus_leptorhynchus_harmonics = dict(
+    amplitudes=(0.90062, 0.15311, 0.072049, 0.012609, 0.011708),
+    phases=(1.3623, 2.3246, 0.9869, 2.6492, -2.6885),
+)
+
+Apteronotus_rostratus_harmonics = dict(
+    amplitudes=(
+        0.64707,
+        0.43874,
+        0.063592,
+        0.07379,
+        0.040199,
+        0.023073,
+        0.0097678,
+    ),
+    phases=(2.2988, 0.78876, -1.316, 2.2416, 2.0413, 1.1022, -2.0513),
+)
+
+Eigenmannia_harmonics = dict(
+    amplitudes=(1.0087, 0.23201, 0.060524, 0.020175, 0.010087, 0.0080699),
+    phases=(1.3414, 1.3228, 2.9242, 2.8157, 2.6871, -2.8415),
+)
+
+Sternarchella_terminalis_harmonics = dict(
+    amplitudes=(
+        0.11457,
+        0.4401,
+        0.41055,
+        0.20132,
+        0.061364,
+        0.011389,
+        0.0057985,
+    ),
+    phases=(-2.7106, 2.4472, 1.6829, 0.79085, 0.119, -0.82355, -1.9956),
+)
+
+Sternopygus_dariensis_harmonics = dict(
+    amplitudes=(
+        0.98843,
+        0.41228,
+        0.047848,
+        0.11048,
+        0.022801,
+        0.030706,
+        0.019018,
+    ),
+    phases=(1.4153, 1.3141, 3.1062, -2.3961, -1.9524, 0.54321, 1.6844),
+)
+
+wavefish_harmonics = dict(
+    Sine=Sine_harmonics,
+    Alepto=Apteronotus_leptorhynchus_harmonics,
+    Arostratus=Apteronotus_rostratus_harmonics,
+    Eigenmannia=Eigenmannia_harmonics,
+    Sternarchella=Sternarchella_terminalis_harmonics,
+    Sternopygus=Sternopygus_dariensis_harmonics,
+)
+"""Amplitudes and phases of EOD waveforms of various species of wave-type electric fish."""
+
+
+def wavefish_spectrum(fish):
+    """Amplitudes and phases of a wavefish EOD.
+
+    Parameters
+    ----------
+    fish: string, dict or tuple of lists/arrays
+        Specify relative amplitudes and phases of the fundamental and its harmonics.
+        If string then take amplitudes and phases from the `wavefish_harmonics` dictionary.
+        If dictionary then take amplitudes and phases from the 'amlitudes' and 'phases' keys.
+        If tuple then the first element is the list of amplitudes and
+        the second one the list of relative phases in radians.
+
+    Returns
+    -------
+    amplitudes: array of floats
+        Amplitudes of the fundamental and its harmonics.
+    phases: array of floats
+        Phases in radians of the fundamental and its harmonics.
+
+    Raises
+    ------
+    KeyError:
+        Unknown fish.
+    IndexError:
+        Amplitudes and phases differ in length.
+    """
+    if isinstance(fish, (tuple, list)):
+        amplitudes = fish[0]
+        phases = fish[1]
+    elif isinstance(fish, dict):
+        amplitudes = fish["amplitudes"]
+        phases = fish["phases"]
+    else:
+        if fish not in wavefish_harmonics:
+            raise KeyError(
+                "unknown wavefish. Choose one of "
+                + ", ".join(wavefish_harmonics.keys())
+            )
+        amplitudes = wavefish_harmonics[fish]["amplitudes"]
+        phases = wavefish_harmonics[fish]["phases"]
+    if len(amplitudes) != len(phases):
+        raise IndexError("need exactly as many phases as amplitudes")
+    # remove NaNs:
+    for k in reversed(range(len(amplitudes))):
+        if np.isfinite(amplitudes[k]) or np.isfinite(phases[k]):
+            amplitudes = amplitudes[: k + 1]
+            phases = phases[: k + 1]
+            break
+    return amplitudes, phases
+
+
+def wavefish_eods(
+    fish="Eigenmannia",
+    frequency=100.0,
+    samplerate=44100.0,
+    duration=1.0,
+    phase0=0.0,
+    noise_std=0.05,
+):
+    """Simulate EOD waveform of a wave-type fish.
+
+    The waveform is constructed by superimposing sinewaves of integral
+    multiples of the fundamental frequency - the fundamental and its
+    harmonics.  The fundamental frequency of the EOD (EODf) is given by
+    `frequency`. With `fish` relative amplitudes and phases of the
+    fundamental and its harmonics are specified.
+
+    The generated waveform is `duration` seconds long and is sampled with
+    `samplerate` Hertz.  Gaussian white noise with a standard deviation of
+    `noise_std` is added to the generated waveform.
+
+    Parameters
+    ----------
+    fish: string, dict or tuple of lists/arrays
+        Specify relative amplitudes and phases of the fundamental and its harmonics.
+        If string then take amplitudes and phases from the `wavefish_harmonics` dictionary.
+        If dictionary then take amplitudes and phases from the 'amlitudes' and 'phases' keys.
+        If tuple then the first element is the list of amplitudes and
+        the second one the list of relative phases in radians.
+    frequency: float or array of floats
+        EOD frequency of the fish in Hertz. Either fixed number or array for
+        time-dependent frequencies.
+    samplerate: float
+        Sampling rate in Hertz.
+    duration: float
+        Duration of the generated data in seconds. Only used if frequency is scalar.
+    phase0: float
+        Phase offset of the EOD waveform in radians.
+    noise_std: float
+        Standard deviation of additive Gaussian white noise.
+
+    Returns
+    -------
+    data: array of floats
+        Generated data of a wave-type fish.
+
+    Raises
+    ------
+    KeyError:
+        Unknown fish.
+    IndexError:
+        Amplitudes and phases differ in length.
+    """
+    # get relative amplitude and phases:
+    amplitudes, phases = wavefish_spectrum(fish)
+    # compute phase:
+    if np.isscalar(frequency):
+        phase = np.arange(0, duration, 1.0 / samplerate)
+        phase *= frequency
+    else:
+        phase = np.cumsum(frequency) / samplerate
+    # generate EOD:
+    data = np.zeros(len(phase))
+    for har, (ampl, phi) in enumerate(zip(amplitudes, phases)):
+        if np.isfinite(ampl) and np.isfinite(phi):
+            data += ampl * np.sin(
+                2 * np.pi * (har + 1) * phase + phi - (har + 1) * phase0
+            )
+    # add noise:
+    data += noise_std * np.random.randn(len(data))
+    return data
+
+
+def normalize_wavefish(fish, mode="peak"):
+    """Normalize amplitudes and phases of wave-type EOD waveform.
+
+    The amplitudes and phases of the Fourier components are adjusted
+    such that the resulting EOD waveform has a peak-to-peak amplitude
+    of two and the peak of the waveform is at time zero (mode is set
+    to 'peak') or that the fundamental has an amplitude of one and a
+    phase of 0 (mode is set to 'zero').
+
+    Parameters
+    ----------
+    fish: string, dict or tuple of lists/arrays
+        Specify relative amplitudes and phases of the fundamental and its harmonics.
+        If string then take amplitudes and phases from the `wavefish_harmonics` dictionary.
+        If dictionary then take amplitudes and phases from the 'amlitudes' and 'phases' keys.
+        If tuple then the first element is the list of amplitudes and
+        the second one the list of relative phases in radians.
+    mode: 'peak' or 'zero'
+        How to normalize amplitude and phases:
+        - 'peak': normalize waveform to a peak-to-peak amplitude of two
+          and shift it such that its peak is at time zero.
+        - 'zero': scale amplitude of fundamental to one and its phase to zero.
+
+    Returns
+    -------
+    amplitudes: array of floats
+        Adjusted amplitudes of the fundamental and its harmonics.
+    phases: array of floats
+        Adjusted phases in radians of the fundamental and its harmonics.
+
+    """
+    # get relative amplitude and phases:
+    amplitudes, phases = wavefish_spectrum(fish)
+    if mode == "zero":
+        newamplitudes = np.array(amplitudes) / amplitudes[0]
+        newphases = np.array(
+            [p + (k + 1) * (-phases[0]) for k, p in enumerate(phases)]
+        )
+        newphases %= 2.0 * np.pi
+        newphases[newphases > np.pi] -= 2.0 * np.pi
+        return newamplitudes, newphases
+    else:
+        # generate waveform:
+        eodf = 100.0
+        rate = 100000.0
+        data = wavefish_eods(fish, eodf, rate, 2.0 / eodf, noise_std=0.0)
+        # normalize amplitudes:
+        ampl = 0.5 * (np.max(data) - np.min(data))
+        newamplitudes = np.array(amplitudes) / ampl
+        # shift phases:
+        deltat = np.argmax(data[: int(rate / eodf)]) / rate
+        deltap = 2.0 * np.pi * deltat * eodf
+        newphases = np.array(
+            [p + (k + 1) * deltap for k, p in enumerate(phases)]
+        )
+        newphases %= 2.0 * np.pi
+        newphases[newphases > np.pi] -= 2.0 * np.pi
+        # return:
+        return newamplitudes, newphases
+
+
+def export_wavefish(fish, name="Unknown_harmonics", file=None):
+    """Serialize wavefish parameter to python code.
+
+    Add output to the wavefish_harmonics dictionary!
+
+    Parameters
+    ----------
+    fish: string, dict or tuple of lists/arrays
+        Specify relative amplitudes and phases of the fundamental and its harmonics.
+        If string then take amplitudes and phases from the `wavefish_harmonics` dictionary.
+        If dictionary then take amplitudes and phases from the 'amlitudes' and 'phases' keys.
+        If tuple then the first element is the list of amplitudes and
+        the second one the list of relative phases in radians.
+    name: string
+        Name of the dictionary to be written.
+    file: string or file or None
+        File name or open file object where to write wavefish dictionary.
+
+    Returns
+    -------
+    fish: dict
+        Dictionary with amplitudes and phases.
+    """
+    # get relative amplitude and phases:
+    amplitudes, phases = wavefish_spectrum(fish)
+    # write out dictionary:
+    if file is None:
+        file = sys.stdout
+    try:
+        file.write("")
+        closeit = False
+    except AttributeError:
+        file = open(file, "w")
+        closeit = True
+    n = 6
+    file.write(name + " = \\\n")
+    file.write("    dict(amplitudes=(")
+    file.write(", ".join(["%.5g" % a for a in amplitudes[:n]]))
+    for k in range(n, len(amplitudes), n):
+        file.write(",\n")
+        file.write(" " * (9 + 12))
+        file.write(", ".join(["%.5g" % a for a in amplitudes[k : k + n]]))
+    file.write("),\n")
+    file.write(" " * 9 + "phases=(")
+    file.write(", ".join(["%.5g" % p for p in phases[:n]]))
+    for k in range(n, len(phases), n):
+        file.write(",\n")
+        file.write(" " * (9 + 8))
+        file.write(", ".join(["%.5g" % p for p in phases[k : k + n]]))
+    file.write("))\n")
+    if closeit:
+        file.close()
+    # return dictionary:
+    harmonics = dict(amplitudes=amplitudes, phases=phases)
+    return harmonics
+
+
+def chirps(
+    eodf=100.0,
+    samplerate=44100.0,
+    duration=1.0,
+    chirp_times=[0.5],
+    chirp_size=[100.0],
+    chirp_width=[0.01],
+    chirp_kurtosis=[1.0],
+    chirp_contrast=[0.05],
+):
+    """Simulate frequency trace with chirps.
+
+    A chirp is modeled as a Gaussian frequency modulation.
+    The first chirp is placed at 0.5/chirp_freq.
+
+    Parameters
+    ----------
+    eodf: float
+        EOD frequency of the fish in Hertz.
+    samplerate: float
+        Sampling rate in Hertz.
+    duration: float
+        Duration of the generated data in seconds.
+    chirp_times: float
+        Timestamps of every single chirp in seconds.
+    chirp_size: list
+        Size of each chirp (maximum frequency increase above eodf) in Hertz.
+    chirp_width: list
+        Width of every single chirp at 10% height in seconds.
+    chirp_kurtosis: list:
+        Shape of every single chirp. =1: Gaussian, >1: more rectangular, <1: more peaked.
+    chirp_contrast: float
+        Maximum amplitude reduction of EOD during every respective chirp.
+
+    Returns
+    -------
+    frequency: array of floats
+        Generated frequency trace that can be passed on to wavefish_eods().
+    amplitude: array of floats
+        Generated amplitude modulation that can be used to multiply the trace generated by
+        wavefish_eods().
+    """
+    # baseline eod frequency and amplitude modulation:
+    n = len(np.arange(0, duration, 1.0 / samplerate))
+    frequency = eodf * np.ones(n)
+    am = np.ones(n)
+
+    for time, width, size, kurtosis, contrast in zip(chirp_times, chirp_width, chirp_size, chirp_kurtosis, chirp_contrast):
+
+        # chirp frequency waveform:
+        chirp_t = np.arange(-2.0 * width, 2.0 * width, 1.0 / samplerate)
+        chirp_sig = (
+            0.5 * width / (2.0 * np.log(10.0)) ** (0.5 / kurtosis)
+        )
+        gauss = np.exp(-0.5 * ((chirp_t / chirp_sig) ** 2.0) ** kurtosis)
+
+
+        # add chirps on baseline eodf:
+        index = int(time * samplerate)
+        i0 = index - len(gauss) // 2
+        i1 = i0 + len(gauss)
+        gi0 = 0
+        gi1 = len(gauss)
+        if i0 < 0:
+            gi0 -= i0
+            i0 = 0
+        if i1 >= len(frequency):
+            gi1 -= i1 - len(frequency)
+            i1 = len(frequency)
+        frequency[i0:i1] += size * gauss[gi0:gi1]
+        am[i0:i1] -= contrast * gauss[gi0:gi1]
+
+    return frequency, am
+
+
+def rises(
+    eodf,
+    samplerate,
+    duration,
+    rise_times,
+    rise_size,
+    rise_tau,
+    decay_tau,
+):
+    """Simulate frequency trace with rises.
+
+    A rise is modeled as a double exponential frequency modulation.
+
+    Parameters
+    ----------
+    eodf: float
+        EOD frequency of the fish in Hertz.
+    samplerate: float
+        Sampling rate in Hertz.
+    duration: float
+        Duration of the generated data in seconds.
+    rise_times: list 
+        Timestamp of each of the rises in seconds.
+    rise_size: list
+        Size of the respective rise (frequency increase above eodf) in Hertz.
+    rise_tau: list
+        Time constant of the frequency increase of the respective rise in seconds.
+    decay_tau: list
+        Time constant of the frequency decay of the respective rise in seconds.
+
+    Returns
+    -------
+    data: array of floats
+        Generate frequency trace that can be passed on to wavefish_eods().
+    """
+    n = len(np.arange(0, duration, 1.0 / samplerate))
+
+    # baseline eod frequency:
+    frequency = eodf * np.ones(n)
+
+    for time, size, riset, decayt in zip(rise_times, rise_size, rise_tau, decay_tau):  
+
+        # rise frequency waveform:
+        rise_t = np.arange(0.0, 5.0 * decayt, 1.0 / samplerate)
+        rise = (
+            size
+            * (1.0 - np.exp(-rise_t / riset))
+            * np.exp(-rise_t / decayt)
+        )
+
+        # add rises on baseline eodf:
+        index = int(time * samplerate)
+        if index + len(rise) > len(frequency):
+            rise_index = len(frequency) - index
+            frequency[index : index + rise_index] += rise[:rise_index]
+            break
+        else:
+            frequency[index : index + len(rise)] += rise
+    return frequency
+
+class FishSignal:
+    def __init__(self, samplerate, duration, eodf, nchirps, nrises):
+        time = np.arange(0, duration, 1 / samplerate)
+        chirp_times = np.random.uniform(0, duration, nchirps)
+        rise_times = np.random.uniform(0, duration, nrises)
+
+        # pick random parameters for chirps 
+        chirp_size = np.random.uniform(60, 200, nchirps)
+        chirp_width = np.random.uniform(0.01, 0.1, nchirps)
+        chirp_kurtosis = np.random.uniform(1, 1, nchirps)
+        chirp_contrast = np.random.uniform(0.1, 0.5, nchirps)
+
+        # pick random parameters for rises
+        rise_size = np.random.uniform(10, 100, nrises)
+        rise_tau = np.random.uniform(0.5, 1.5, nrises)
+        decay_tau = np.random.uniform(5, 15, nrises)
+
+        # generate frequency trace with chirps
+        chirp_trace, chirp_amp = chirps(
+            eodf=0.0,
+            samplerate=samplerate,
+            duration=duration,
+            chirp_times=chirp_times,
+            chirp_size=chirp_size,
+            chirp_width=chirp_width,
+            chirp_kurtosis=chirp_kurtosis,
+            chirp_contrast=chirp_contrast,
+        )
+
+        # generate frequency trace with rises
+        rise_trace = rises(
+            eodf=0.0,
+            samplerate=samplerate,
+            duration=duration,
+            rise_times=rise_times,
+            rise_size=rise_size,
+            rise_tau=rise_tau,
+            decay_tau=decay_tau,
+        )
+
+        # combine traces to one
+        full_trace = chirp_trace + rise_trace + eodf
+
+        # make the EOD from the frequency trace
+        fish = wavefish_eods(
+            fish="Alepto",
+            frequency=full_trace,
+            samplerate=samplerate,
+            duration=duration,
+            phase0=0.0,
+            noise_std=0.05,
+        )
+
+        signal = fish * chirp_amp
+
+        self.signal = signal
+        self.trace = full_trace
+        self.time = time
+        self.samplerate = samplerate
+        self.eodf = eodf
+
+    def visualize(self):
+
+        spec, freqs, spectime = ps.spectrogram(
+            data=self.signal,
+            ratetime=self.samplerate,
+            freq_resolution=0.5,
+            overlap_frac=0.5,
+        )
+
+        fig, (ax1, ax2) = plt.subplots(2, 1, height_ratios=[1, 4], sharex=True)
+
+        ax1.plot(self.time, self.signal)
+        ax1.set_ylabel("Amplitude")
+        ax1.set_xlabel("Time (s)")
+        ax1.set_title("EOD signal")
+
+        ax2.imshow(ps.decibel(spec), origin='lower', aspect="auto", extent=[spectime[0], spectime[-1], freqs[0], freqs[-1]])
+        ax2.set_ylabel("Frequency (Hz)")
+        ax2.set_xlabel("Time (s)")
+        ax2.set_title("Spectrogram")
+        ax2.set_ylim(0, 2000)
+        plt.show()
diff --git a/chirp_instantaneous_freq/test_parameters.py b/chirp_instantaneous_freq/test_parameters.py
new file mode 100644
index 0000000..9c4ab5f
--- /dev/null
+++ b/chirp_instantaneous_freq/test_parameters.py
@@ -0,0 +1,118 @@
+import numpy as np 
+import matplotlib.pyplot as plt
+from fish_signal import chirps, wavefish_eods
+from filters import bandpass_filter, instantaneous_frequency, inst_freq
+from IPython import embed
+
+
+def switch_test(test, defaultparams, testparams):
+    if test == 'width':
+        defaultparams['chirp_width'] = testparams['chirp_width']
+        key = 'chirp_width'
+    elif test == 'size':
+        defaultparams['chirp_size'] = testparams['chirp_size']
+        key = 'chirp_size'
+    elif test == 'kurtosis':
+        defaultparams['chirp_kurtosis'] = testparams['chirp_kurtosis']
+        key = 'chirp_kurtosis'
+    elif test == 'contrast':
+        defaultparams['chirp_contrast'] = testparams['chirp_contrast']
+        key = 'chirp_contrast'
+    else:
+        raise ValueError("Test not recognized")
+
+    return key, defaultparams
+
+
+def extract_dict(dict, index):
+    return {key: value[index] for key, value in dict.items()}
+
+
+def main(test1, test2, resolution=10):
+
+    assert test1 in ['width', 'size', 'kurtosis', 'contrast'], "Test1 not recognized"
+    assert test2 in ['width', 'size', 'kurtosis', 'contrast'], "Test2 not recognized"
+
+    # Define the parameters for the chirp simulations 
+    ntest = resolution
+
+    defaultparams = dict(
+        chirp_size = np.ones(ntest) * 100, 
+        chirp_width = np.ones(ntest) * 0.1, 
+        chirp_kurtosis = np.ones(ntest) * 1.0, 
+        chirp_contrast = np.ones(ntest) * 0.5, 
+    )
+
+    testparams = dict(
+        chirp_width = np.linspace(0.01, 0.2, ntest), 
+        chirp_size = np.linspace(50, 300, ntest), 
+        chirp_kurtosis = np.linspace(0.5, 1.5, ntest), 
+        chirp_contrast = np.linspace(0.01, 1.0, ntest), 
+    )
+
+    key1, chirp_params = switch_test(test1, defaultparams, testparams)
+    key2, chirp_params = switch_test(test2, chirp_params, testparams)
+
+    # make the chirp trace 
+    eodf = 500
+    samplerate = 20000
+    duration = 2
+    chirp_times = [0.5, 1, 1.5]
+
+    wide_cutoffs = 200
+    tight_cutoffs = 10
+
+    distances = np.full((ntest, ntest), np.nan)
+    
+    fig, axs = plt.subplots(ntest, ntest, figsize = (10, 10), sharex = True, sharey = True)
+    axs = axs.flatten()
+
+    iter0 = 0
+    for iter1, test1_param in enumerate(chirp_params[key1]):
+        for iter2, test2_param in enumerate(chirp_params[key2]):
+
+            # get the chirp parameters for the current test
+            inner_chirp_params = extract_dict(chirp_params, iter2)
+            inner_chirp_params[key1] = test1_param
+            inner_chirp_params[key2] = test2_param
+
+            # make the chirp trace for the current chirp parameters
+            sizes = np.ones(len(chirp_times)) * inner_chirp_params['chirp_size']
+            widths = np.ones(len(chirp_times)) * inner_chirp_params['chirp_width']
+            kurtosis = np.ones(len(chirp_times)) * inner_chirp_params['chirp_kurtosis']
+            contrast = np.ones(len(chirp_times)) * inner_chirp_params['chirp_contrast']
+
+            # make the chirp trace
+            chirp_trace, ampmod = chirps(eodf, samplerate, duration, chirp_times, sizes, widths, kurtosis, contrast)
+            signal = wavefish_eods(
+                    fish="Alepto", 
+                    frequency=chirp_trace, 
+                    samplerate=samplerate, 
+                    duration=duration, 
+                    phase0=0.0, 
+                    noise_std=0.05
+            )           
+            signal = signal * ampmod
+
+            # apply broadband filter 
+            wide_signal = bandpass_filter(signal, samplerate, eodf - wide_cutoffs, eodf + wide_cutoffs)
+            tight_signal = bandpass_filter(signal, samplerate, eodf - tight_cutoffs, eodf + tight_cutoffs)
+
+            # get the instantaneous frequency
+            wide_frequency = inst_freq(wide_signal, samplerate)
+            tight_frequency = inst_freq(tight_signal, samplerate)
+
+            bool_mask = wide_frequency != 0
+            axs[iter0].plot(wide_frequency[bool_mask])
+            axs[iter0].plot(tight_frequency[bool_mask])
+            fig.supylabel(key1)
+            fig.supxlabel(key2)
+
+            iter0 += 1
+
+    fig, ax = plt.subplots()
+    ax.imshow(distances, cmap = 'jet')
+    plt.show()
+
+if __name__ == "__main__":
+    main('width', 'size') 
diff --git a/requirements.txt b/requirements.txt
index b6a16c7..00bb2e1 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,3 @@
-audioio==0.10.0
 cmocean==3.0.3
 cycler==0.11.0
 ipython==8.12.0
@@ -9,5 +8,4 @@ paramiko==3.1.0
 PyYAML==6.0
 scipy==1.10.1
 scp==0.14.5
-thunderfish==1.9.10
 tqdm==4.65.0