使用蓝牙5.2 LE技术实现CROS/Bi-CROS听力助听器功能，可以通过以下代码实现：

// 初始化蓝牙适配器
BluetoothAdapter bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();

// 获取蓝牙设备
BluetoothDevice bluetoothDevice = bluetoothAdapter.getRemoteDevice(deviceAddress);

// 获取GATT服务
BluetoothGatt bluetoothGatt = bluetoothDevice.connectGatt(context, false, gattCallback);

// 设置CROS/Bi-CROS听力助听器服务UUID
UUID serviceUuid = UUID.fromString("00001828-0000-1000-8000-00805f9b34fb");

// 获取服务
BluetoothGattService service = bluetoothGatt.getService(serviceUuid);

// 设置CROS/Bi-CROS听力助听器通道UUID
UUID characteristicUuid = UUID.fromString("00002a56-0000-1000-8000-00805f9b34fb");

// 获取通道
BluetoothGattCharacteristic characteristic = service.getCharacteristic(characteristicUuid);

// 设定通知特征
bluetoothGatt.setCharacteristicNotification(characteristic, true);

// 设置CROS/Bi-CROS功能
byte[] value = {0x01};
characteristic.setValue(value);
bluetoothGatt.writeCharacteristic(characteristic);