diff --git a/src/core/hle/service/audio/audin_u.cpp b/src/core/hle/service/audio/audin_u.cpp
index d7f1d348d5..3e22994269 100644
--- a/src/core/hle/service/audio/audin_u.cpp
+++ b/src/core/hle/service/audio/audin_u.cpp
@@ -2,6 +2,9 @@
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
+#include "common/logging/log.h"
+#include "core/hle/ipc_helpers.h"
+#include "core/hle/kernel/hle_ipc.h"
 #include "core/hle/service/audio/audin_u.h"
 
 namespace Service::Audio {
@@ -36,11 +39,12 @@ public:
 AudInU::AudInU() : ServiceFramework("audin:u") {
     // clang-format off
     static const FunctionInfo functions[] = {
-        {0, nullptr, "ListAudioIns"},
-        {1, nullptr, "OpenAudioIn"},
-        {2, nullptr, "Unknown"},
-        {3, nullptr, "OpenAudioInAuto"},
-        {4, nullptr, "ListAudioInsAuto"},
+        {0, &AudInU::ListAudioIns, "ListAudioIns"},
+        {1, &AudInU::OpenAudioIn, "OpenAudioIn"},
+        {2, &AudInU::ListAudioIns, "ListAudioInsAuto"},
+        {3, &AudInU::OpenAudioIn, "OpenAudioInAuto"},
+        {4, &AudInU::ListAudioInsAutoFiltered, "ListAudioInsAutoFiltered"},
+        {5, &AudInU::OpenAudioInProtocolSpecified, "OpenAudioInProtocolSpecified"},
     };
     // clang-format on
 
@@ -49,4 +53,60 @@ AudInU::AudInU() : ServiceFramework("audin:u") {
 
 AudInU::~AudInU() = default;
 
+void AudInU::ListAudioIns(Kernel::HLERequestContext& ctx) {
+    LOG_DEBUG(Service_Audio, "called");
+    const std::size_t count = ctx.GetWriteBufferSize() / sizeof(AudioInDeviceName);
+
+    const std::size_t device_count = std::min(count, audio_device_names.size());
+    std::vector<AudioInDeviceName> device_names;
+    device_names.reserve(device_count);
+
+    for (std::size_t i = 0; i < device_count; i++) {
+        const auto& device_name = audio_device_names[i];
+        auto& entry = device_names.emplace_back();
+        device_name.copy(entry.data(), device_name.size());
+    }
+
+    ctx.WriteBuffer(device_names);
+
+    IPC::ResponseBuilder rb{ctx, 3};
+    rb.Push(RESULT_SUCCESS);
+    rb.Push(static_cast<u32>(device_names.size()));
+}
+
+void AudInU::ListAudioInsAutoFiltered(Kernel::HLERequestContext& ctx) {
+    LOG_DEBUG(Service_Audio, "called");
+    constexpr u32 device_count = 0;
+
+    // Since we don't actually use any other audio input devices, we return 0 devices. Filtered
+    // device listing just omits the default input device
+
+    IPC::ResponseBuilder rb{ctx, 3};
+    rb.Push(RESULT_SUCCESS);
+    rb.Push(static_cast<u32>(device_count));
+}
+
+void AudInU::OpenInOutImpl(Kernel::HLERequestContext& ctx) {
+    AudInOutParams params{};
+    params.channel_count = 2;
+    params.sample_format = SampleFormat::PCM16;
+    params.sample_rate = 48000;
+    params.state = State::Started;
+
+    IPC::ResponseBuilder rb{ctx, 6, 0, 1};
+    rb.Push(RESULT_SUCCESS);
+    rb.PushRaw<AudInOutParams>(params);
+    rb.PushIpcInterface<IAudioIn>();
+}
+
+void AudInU::OpenAudioIn(Kernel::HLERequestContext& ctx) {
+    LOG_WARNING(Service_Audio, "(STUBBED) called");
+    OpenInOutImpl(ctx);
+}
+
+void AudInU::OpenAudioInProtocolSpecified(Kernel::HLERequestContext& ctx) {
+    LOG_WARNING(Service_Audio, "(STUBBED) called");
+    OpenInOutImpl(ctx);
+}
+
 } // namespace Service::Audio
diff --git a/src/core/hle/service/audio/audin_u.h b/src/core/hle/service/audio/audin_u.h
index 0538b9560f..a599f4a648 100644
--- a/src/core/hle/service/audio/audin_u.h
+++ b/src/core/hle/service/audio/audin_u.h
@@ -16,6 +16,35 @@ class AudInU final : public ServiceFramework<AudInU> {
 public:
     explicit AudInU();
     ~AudInU() override;
+
+private:
+    enum class SampleFormat : u32_le {
+        PCM16 = 2,
+    };
+
+    enum class State : u32_le {
+        Started = 0,
+        Stopped = 1,
+    };
+
+    struct AudInOutParams {
+        u32_le sample_rate{};
+        u32_le channel_count{};
+        SampleFormat sample_format{};
+        State state{};
+    };
+    static_assert(sizeof(AudInOutParams) == 0x10, "AudInOutParams is an invalid size");
+
+    using AudioInDeviceName = std::array<char, 256>;
+    static constexpr std::array<std::string_view, 1> audio_device_names{{
+        "BuiltInHeadset",
+    }};
+
+    void ListAudioIns(Kernel::HLERequestContext& ctx);
+    void ListAudioInsAutoFiltered(Kernel::HLERequestContext& ctx);
+    void OpenInOutImpl(Kernel::HLERequestContext& ctx);
+    void OpenAudioIn(Kernel::HLERequestContext& ctx);
+    void OpenAudioInProtocolSpecified(Kernel::HLERequestContext& ctx);
 };
 
 } // namespace Service::Audio