An animating waveform view made with SwiftUI as seen here: https://mastodon.social/@mortengregersen/110377187270004199

WaveformView.swift

//
//  WaveformView.swift
//  HeyAIku
//
//  Created by Morten Bjerg Gregersen on 16/05/2023.
//

import SwiftUI

struct WaveformView: View {
    @State private var waveformLines: [WaveformLine] = []
    private let timer = Timer.publish(every: 0.2, on: .main, in: .common).autoconnect()

    var body: some View {
        HStack(spacing: 3) {
            ForEach(waveformLines) { $0 }
        }
        .onReceive(timer, perform: { _ in
            regenerateWaveform()
        })
        .onAppear {
            regenerateWaveform()
        }
    }

    private func regenerateWaveform() {
        let minHeight: CGFloat = 10
        let maxHeight: CGFloat = 30
        let delta: CGFloat = 10
        withAnimation(Animation.easeInOut) {
            var previousLine: WaveformLine?
            waveformLines = (0..<5).map {
                let lowerBound, upperBound: CGFloat
                if waveformLines.isEmpty {
                    lowerBound = minHeight
                    upperBound = maxHeight
                } else if let previousLine {
                    lowerBound = max(previousLine.height - delta, minHeight)
                    upperBound = min(previousLine.height + delta, maxHeight)
                } else {
                    lowerBound = max(waveformLines[$0].height - delta, minHeight)
                    upperBound = min(waveformLines[$0].height + delta, maxHeight)
                }
                let currentLine = WaveformLine(id: $0, height: CGFloat.random(in: lowerBound..<upperBound))
                previousLine = currentLine
                return currentLine
            }
        }
    }

    struct WaveformLine: View, Identifiable {
        let id: Int
        let height: CGFloat

        var body: some View {
            RoundedRectangle(cornerRadius: 1)
                .frame(width: 2, height: height)
        }
    }
}

struct WaveformView_Previews: PreviewProvider {
    static var previews: some View {
        WaveformView()
    }
}