Windows Vista Team Blog : Windows Vista, Audio

Behind the Scenes of the Windows Vista Sound Schemes

Chris Flores — Sat, 14 Jun 2008 00:54:00 GMT

I'm posting this on behalf of my colleague Steve Ball.

Hi, my name is Steve Ball and I'm a Principal Program Manager Lead on the Windows Sound Team. I'd like to take a moment and give some background on sound schemes in Windows as well as the new sound schemes released as Ultimate Extras and their relationship with the default Windows Vista scheme.

Default Windows Vista Sound Scheme
The default Windows Vista sound scheme was designed with the same principles that were used in designing the Windows Vista visual elements and desktop experience. In contrast, the Windows XP sounds, while appropriate at the time and for that product design, were very ‘Western' and literal, using pianos and western orchestral instruments. The XP sounds were designed to complement the ‘photo-realistic' Bliss desktop (blue sky, green grass photo.) The Windows XP sounds can also be rather percussive and jarring in the context of day to day PC use, so it was an explicit goal to re-orchestrate the default Windows Vista sounds to complement the softer, cleaner theme and user interface elements in Windows Vista.

For Windows Vista, it was an intentional design goal to avoid ‘reinventing' the User Interface language for sound. For example, the "new mail" sound in Windows XP and in Windows Vista consist of the same pitches, interval, and timing.

New Mail (Notify)

The Windows Vista ‘new mail' sound has simply been re-orchestrated to match the softer, more -rounded Windows Vista Startup Sound whose ‘sonic palette' was derived from the gentle and flowing Robert Fripp Soundscapes sessions that were recorded at Microsoft Studios in 2005 and 2006.

Session 1: http://channel9.msdn.com/Showpost.aspx?postid=151853

Session 2: http://channel9.msdn.com/showpost.aspx?postid=287615

Fan Fact: The shutdown sounds for both of the new UE Sound Schemes are pulled directly from these Fripp sessions. There are in fact two shutdown sounds included with each of these UE schemes - for each scheme, there is also longer shutdown sound in the %windir%/media/%scheme_name% folder that is actually too long to use as a Windows Vista shutdown sound -- but we included it anyway so Fripp fans could get a greater sense of context about where this shorter sound came from - or map it manually to a different sound event if they wish.

Here is some additional background about each of the new schemes:

Ultimate Extras Glass Sound Scheme
The "Ultimate Extras Glass" sound scheme utilizes the same design language and principles as the default Windows Vista sound scheme, however, this set has an additional glassy ‘edge' that can be heard as a more percussive envelope applied to each of the sounds. From one point of view, the sounds in this set feel like they are made with ‘glass' instruments. The sounds in this set have a sort of clinking glass root with a polished or ‘frosted' haze effect applied to their outer surface - this is intended to be directly analogous to the transparent ‘glassy' window effects that are built-in to the Windows Vista chrome.

Ultimate Extras Pearl Sound Scheme
The Pearl sound scheme further extends the intentionally-subtle design attributes of both the Windows Vista default sound scheme and the Ultimate Extras Glass scheme, with less focus on reverberant, sometimes clinking ‘glassy' sounds in exchange for a richer, milky, more percussive sonic palate. The Pearl sounds are harder and less reflective and reverberant, more like the rich and rounded surface of a pearl in contrast to the fragile resonance of a wine glass. More concretely, the Pearl sounds are cleaner, clearer, and brighter than the ‘Glass' sound scheme.

Both of the new Ultimate Extras sound schemes embody more percussive elements in contrast to the soft edges of default Windows Vista sound scheme and they extend of the existing sound design language established by XP and Windows Vista. Functionally, the percussive elements of these sound schemes may also help users hear Windows events from a greater distance, if that is desired. They are intended to provide an extended personalization option for users who wish to differentiate their Windows Vista experience from the default experience.

Occasionally, people stop me in coffee shops and cafes and ask: did the Robert Fripp sounds make it into Windows Vista? There is a long answer and a short answer. Here is the short: the Windows Vista Startup Sound is the primary "Fripp" appearance in Windows Vista, although many of the new inbox sounds were orchestrated based upon the sound and feel of the hours of Fripp Soundscapes we recorded at our Windows Vista sessions.

For some additional background on the Windows Vista sounds, click here to check out our Windows Vista Sounds Q&A.

If there is interest, I can go deeper in future posts about any of these areas.

- Steve

Using S/PDIF to send audio from your PC

Nick White — Wed, 05 Mar 2008 00:29:00 GMT

The following is an article from another of my colleagues on the Windows Vista Sound team, Kristin Carr. Kristin is a Program Manager and works with Steve Ball, who previously has shared his insights into how Windows Vista handles sound. If you have questions for Kristin, please leave a comment below.

Many people have a general idea of what S/PDIF is -- perhaps by seeing it as a label on an audio output, or on a feature list for a product. But what is it exactly, and how do you use it? This post will cover some of those details.

On a PC, the audio is stored and processed digitally until the final output stage when it is usually converted to an analog signal that directly feeds your speakers. However, there may be times when you want to transmit the signal digitally to a different device that will be used to play the sound, such as a receiver. In these cases, you may want to postpone converting the signal to an analog one, and instead transmit the signal digitally to avoid any degradation and additional noise that may occur when transmitting an analog signal.

For this purpose, S/PDIF (Sony/Philips Digital Interconnect Format) was developed. Often referred to by the name of the connector (including Toslink, RCA, or simply "Optical" or "Digital Out"), S/PDIF specifies a method of transmitting a digital signal so that it can be received and interpreted correctly by the connected device. You may ask yourself, "How complicated is it to transmit a signal? Why do we need a special protocol?" Consider that the digital signal consists of a series of bits, and within that series, the bits are grouped to correspond to a sample of audio, and an even larger subset of those are grouped to correspond to a particular channel. In order to enable a receiver to properly interpret all of those bits in the correct order, it is necessary to have a format for transmitting those bits. This is where S/PDIF comes in.

S/PDIF can be used to transmit two channels of digital audio in real time over a single connection. S/PDIF specifies a particular bit pattern that a receiver can use to latch onto the stream. Once the receiver has synced up with the stream, S/PDIF specifies the order of the audio bits and how they should be arranged in a stream so that the receiver can properly interpret it.

However, there may be times when you wish to transmit more than two channels of audio over the S/PDIF link. This is where compressed audio can be used. Audio compression is a technique used to transmit equivalent information using fewer bits. This is done through a number of techniques. Some techniques, referred to as perceptual coding, take advantage of the fact that humans can only hear certain sounds. These methods of compression usually involve discarding bits that only contribute a minimal amount to what a listener needs to recognize a given sound. Other methods take advantage of numerical redundancies in the signal in order to effectively transmit the same information in a smaller amount of space. Dolby Digital and DTS are two common types of compression. Regardless of the technique, compression enables a digital audio signal to use fewer bits to transmit the audio.

The result of this compression is that it enables you to transmit the content for up to 5.1 channels of audio over S/PDIF in space that would have only fit 2 channels if the audio had been uncompressed. This is great once the signal has been encoded (synonymous with compressed), but once a signal has been encoded, that same signal must also be decoded after it has been received so that it can be sent to speakers. This means that your receiver must be capable of decoding the compressed audio signal in order for you to hear the correct sound. This is the tradeoff necessary to allow you to transmit more than two channels of audio over S/PDIF.

Another direct consequence of transmitting a compressed audio signal instead of an uncompressed audio signal (more commonly known as PCM) is that the volume of that signal cannot be modified once it has been encoded. Because the bits in an encoded signal no longer directly correspond to the volume of that signal, it is impossible to increase the volume until it is decoded. This explains why your PC cannot control the volume of your sound when you are using Dolby Digital or DTS as the output. The connected device will be the only place where the volume can be changed.

To recap, in order to avoid the electrical interference and noise present on an analog connection, consider using S/PDIF to transmit the signal digitally. If you'd like to transmit more than two channels, consider sending encoded content which allows you up to 5.1 channels over S/PDIF. You may also want to consider HDMI, but that's a post for another time!

Microphone Arrays: Digital Microphones

Nick White — Sat, 10 Nov 2007 02:54:00 GMT

Below is part 2 of an audio series by Windows Vista Sound team Program Manager Richard Fricks, the first being Richard's piece on Using a microphone array to enhance sound capture. This follow-on article details how to get more out of your PC by using a digital microphone.

The digital microphone is a perfect fit for Windows Vista's microphone array technology. Digital microphones have been around for years, but until recently, the ability to integrate such technology into an everyday laptop computer at an affordable price has not. Did I mention they are incredibly compact? Here is a picture of a bottom-port Akustica digital microphone:

Akustica AKU2000

This is a great example of a high quality, cost-effective digital microphone that is easily integrated into a laptop PC.

There are some unique characteristics of this particular microphone that warrant mention. First of all, Akustica has a unique fabrication process that allows them to incorporate the entire design onto a single chip of silicon. This monolithic design places the sensor, microphone circuitry, amplifier and converter all together on one chip. This is a great step forward that provides significant advantages over analog microphones as well as other digital microphones that require multiple chips. One of the easiest advantages to articulate is its superior immunity to RF interference.

For comparison purposes, listen to the following audio clips. These clips were made using the same laptop equipped with both a traditional electric condenser microphone (ECM) and an Akustica digital microphone. They provide a clear example of how electrical noise can inject itself into the audio capture stream and how well the Akustica digital microphone is at rejecting this interference.

Wi-Fi Interference

GSM Noise

Any of those noises sound familiar? After I heard the GSM noise, I found myself thinking "Oh, so that's what was causing that strange sound on my PC speakers every time my mobile phone rang!"

Another advantage of the digital microphone is the flexibility it provides in placement. A good place to position a microphone is in the screen's bezel. However, this is also a location where there is a lot of RF noise. With its excellent immunity to such interference, the digital microphone can easily be placed in this area where it is not only less susceptible to keyboard, hard-drive and other physical noises, but also allows for a position that is more directly aligned with the talker's voice.

Single-chip digital microphones also have low manufacturing tolerances, which makes them more suitable for microphone-array applications where microphone matching is important.

If you are shopping for a computer equipped with a microphone array for use with Windows Vista, you need to keep in mind the various microphone array geometries that are supported. The array geometry refers to the number, type, and position of the microphones. The microphone array technology on Windows Vista was carefully tuned to provide the highest level of support for the following two and four microphone array geometries:

Small two-element Array: This geometry consists of two microphones, 100mm apart.

Big two-element Array: This geometry consists of two microphones, 200mm apart.

Linear four-element array: This geometry consists of four microphones with the far right and far left microphone 190 mm apart and the inner two microphones 55mm apart. A second geometry layout allows for the far right and left microphones to be 160mm apart and the inner two microphones to be 70mm apart.

L-Shaped four-element array: This geometry consists for four microphones mounted in the shape of the letter 'L'. It actually looks like a backwards upside down 'L', but that would make for too cumbersome of a name!

This design is targeted for a tablet PC where the screen can be flipped around. When writing on the table, this screen position can cause the hand to cover its lower right or left corners. By positioning the microphones in the manner described here, the hand will not interfere with the microphones' operation.

In general, the more microphones in the array the better, but here is a general rule of thumb:

If you will be recording in a quiet office and will be sitting no more than 2 feet away from the computer then a microphone array equipped with two microphones should be sufficient.
If you will be recording in an office or cubicle with normal noise levels and up to 6ft away from the computer then a microphone array equipped with 4 microphones should be sufficient.

In either case, I highly recommend finding a laptop equipped with digital microphones.

For those programmers out there who want to learn how to capture audio processed by Windows Vista's microphone array technology, I hope to be ready to share my programming experiences with you sometime in November.

If you'd like to dig deeper into the topics I have presented above, you can find some great white papers under the subject "Microphone Arrays" here.

Thanks for reading and happy recording!

- Richard Fricks, Program Manager, Windows Sound Team

An Overview of Windows Sound and Music "Glitching" Issues

Nick White — Mon, 29 Oct 2007 21:35:00 GMT

The following post comes from my colleague Steve Ball, Senior Program Manager for Sound in Windows Vista, and continues his team's on-going series on how Windows Vista treats various forms of audio.

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Part I: Why does my Windows sound sometimes "glitch?"

Windows is a rich and complex OS designed for multi-tasking users whose tasks must share access to scarce system hardware and resources. Unfortunately, despite multiple decades of incredible advances in PC and CPU architectures, there are non-trivial, complex interactions between applications, processes, and devices in even the most advanced personal computers that make a supposedly "easy" task -- like playing back music without occasional glitches -- much more difficult than it may seem at first glance.

Another way of thinking about this: it seems odd that a modern >$2000 PC may sometimes have trouble seamlessly playing back music when $20 CD players can effortlessly playback music without glitches.

So why do many $2000 PCs occasionally glitch while playing back music? The quick answer is this: Windows is not a single-function device like a CD player.

A slightly longer answer goes like this: even an average Windows machine today is commonly used simultaneously as a media player, word processor, presentation projector, spreadsheet number cruncher, authoring tool, photo editor, media server, video recorder, music composition tool, communications device, search engine, virus detector, data compressor and decompressor, and backup manager. And these are only a few of the possible tasks and processes that are run at the same time on the hundreds of millions of Windows machines that are in use today. Each of these tasks or processes, in isolation, would hardly tax the resources of modern PC hardware. But in our multi-tasking world, unavoidable resource conflicts do sometimes occur between the huge and diverse ecosystem of Windows hardware that enables these tasks. Even on the most expensive, brand-new machine, occasional glitches can occur if and when the system attempts to divide its finite resources among these multiple, diverse, independent, power-hungry activities.

What is a glitch?

A glitch is a perceivable error, gap or pop in the sound caused by discontinuities in the audio signal during playback or recording which result from processing or timing problems. Glitches during music playback can sound like a loud "pop" or like a brief slice of silence randomly inserted where your music should have been. Some customers have also described what "glitching" in their own words as:

audio stops a little bit
breaks up
choppy
clicking
corruption
crackle/crackling/crackly
interruption
jitters
jumpy
skipping/skip/skips

For the purpose of this discussion, let's lump all of these descriptions together under one general class of problems and call these "glitching." While a glitch that happens during music playback can be annoying and unsettling, a glitch that occurs while you are recording or communicating with someone can result in frustrating and unacceptable data loss.

What causes my Windows sound and music to glitch?

Digital media processing is time-sensitive. Playback requires specific work to be performed by a given deadline -- otherwise presentation or data loss can occur. A "glitch" occurs when a deadline for time-sensitive processing is missed or when time-sensitive data is lost.

For example, in Windows Vista, playing back music involves "work" that must be done at least every 10 milliseconds so that there can be a continuous stream of music out to your speakers. The "simple" task of playing back music consists of the following steps, all of which must be completed before a strict deadline:

a small chunk of data from a music file needs to be read from a disc (CD or hard drive)
this data needs to be "decompressed" or "decoded" (usually in system memory) so it can be streamed out to your speakers in a format that your sound hardware understands
the decompressed sound data needs to be copied from system memory to your sound hardware memory
the data in your sound hardware needs to be sent to your speakers at the appropriate time
repeat steps 1-4 flawlessly every 10 milliseconds (ms)

In this example, if any of these steps aren't completed on time, then the user could hear a glitch in the music playback.

Elliot Omiya, Architect on the Sound dev team, puts this 10ms cycle into perspective: "it's just slightly longer than the time it takes a nerve impulse to travel from the end of your finger to your brain (~8ms), known as NCV (nerve conduction velocity). Because synapses are like network switches, there is switching time involved before the nerve impulse gets to the brain, i.e., switching time adds to latency."

There is some good news in this story: Windows developers have made significant progress over the years in reducing glitching across key multimedia scenarios. For example, music playback on an otherwise "lightly loaded" system can be generally as smooth as that $20 CD player.

But because of the multi-tasking nature of Windows and the vast array of new and legacy hardware in the ~1B PCs that are used to playback music today, this allegedly simple process is made more complex by the resource sharing that occurs between applications and hardware. For example, it is not uncommon for certain older devices driver to occasionally "lock out" the CPU for 10-50ms, thereby causing obvious audio glitches. This is just one example of the kinds of complex hardware, driver, and OS interactions that can cause glitches.

In summary, some of the common sources of glitches today include:

CPU starvation
GPU starvation
Resource contention from devices and drivers (sometimes called "IO contention")
Network devices
And, of course ... bugs in applications, OS, drivers and/or hardware

My colleague on the Windows Sound team, Larry Osterman, also pointed out to me recently that humans are actually "hard-wired" to be disturbed by audio glitches. In an exchange about this topic, Larry observed that audio glitches are more obvious than video glitches because the ear's tuned to notice high frequency transients -- his visceral example of this idea is an image of a stick snapping in the woods behind you as an audio event that wakes you up before a bear wanders into your path.

In my second post on this topic, I'll go a bit deeper in sharing details of work we’ve done in Windows Vista to address some of the known sources of potential sound glitches, including some additional background about a recent discovery of an apparent connection between multimedia playback and network throughput.

I wish to acknowledge the contributions and suggestions from my colleagues Hakon Strande, Richard Fricks, Alex Ferreira, Lan Ye, Larry Osterman and Elliot Omiya for this series of posts.

Using a microphone array to enhance sound capture

Nick White — Mon, 24 Sep 2007 20:10:00 GMT

Below is a post from my colleague Richard Fricks, a Program Manager on the Windows Vista Audio team, discussing Windows Vista's treatment of microphone arrays when used to capture audio. If this entry prompts questions, let me know via the Comments section below and I'll pass them along to Richard.

Providing a solid audio capture experience is not a simple task. It requires a holistic approach that takes into consideration the entire life-time of the audio signal. A weakness at any one point in the path can result in a degraded signal. Take as an example this recording:

This was made from my laptop. Can you hear all that noise? It's caused by electrical interference from components inside the laptop itself. As you can tell, even the physical layout of the components in the PC can impact the quality of the audio signal. When you consider room acoustics such as reverberation and background noise you may find that the signal that is going into the microphone may not be that good to start out with. Couple that with potential electrical interferences from other sources and chances for a high-quality signal arriving at the application can be bleak.

The solution? You could invest in a recording booth, high-end studio microphone, and some high-quality shielded cables. Or, you could use Windows Vista's new Microphone Array technology. The former can cost many thousands of dollars. The latter comes free with Windows Vista and when coupled with a PC equipped with a microphone array, the results can be dramatic.

So what exactly is a microphone array?

Simply stated, a microphone array is two or more microphones used at the same time to capture sound. Windows Vista supports microphone arrays that consist of two or four microphones. The advantage of using more than one microphone to capture sound is that it allows the software that is processing the microphone signals to determine the position of the sound in the room. This is accomplished by comparing the arrival times of the sound to each of the microphones. For example, if the sound comes into the microphone on the right before it enters the microphone on the left, then you know the person talking is to the right of the PC. During sound capturing, the microphone array software searches for the speaker's position and aims a capturing beam in that direction. If the person speaking moves, the capture beam will follow the sound. It's like having two highly directional microphones: one constantly scanning the workspace measuring the sound level, and the other pointing to the direction with the highest sound level; that is, to the person talking. In addition, the higher directivity of the microphone array reduces the amount of captured ambient noises and reverberated sound. The result? A much clearer representation of the speaker's voice.

The real strength in Windows Vista for improving microphone capture quality, however, is not just its microphone array technology. Remember when I mentioned that good quality capture requires a holistic approach? Windows Vista has acted on this precept by integrating its Microphone Array technology as part of a complete end-to-end strategy. This strategy starts at the microphone and covers the audio signal all the way up to the application. Approaches that do not consider this can find that the high-quality signal it produced can quickly be negated by problems that occur later in the path.

Consider the following. A third-party provider of microphone array technology will generally embed this functionality inside the audio device driver. However, if the microphone array functionality is performed inside the audio device driver then the signal sent to the Acoustic Echo Cancellation (AEC) component in Windows Vista is unable to perform the echo cancellation effectively. This is due to the fact that the signals that started out as individual streams coming from each microphone will have already been merged together by the microphone array processor. This combined signal coming into the AEC as a single stream does not contain the necessary per-stream information needed, and as a result the AEC's ability to properly remove echoes from the stream is greatly impaired. With Windows Vista's end-to-end approach, each signal processing function works together in the proper order to assure the highest quality audio signal can be generated. The following chart shows how all of these components fit together inside Windows Vista:

The above chart shows that in addition to the microphone array processing, Windows Vista also provides the following Digital Signal Processing:

Acoustic Echo Cancellation
Stationary Noise Suppressor
Automatic Gain Control
Wideband quality sound capture and processing

Are you looking to expand the use of computer technology in the area of communications, speech recognition, or just simple voice recordings for email or note-taking? If so, Microphone Array technology in Windows Vista is definitely something you are going to want to look into. In my next post, I will go into the details you should consider when looking for a computer equipped with a microphone array. In a follow-up post to that one, I will cover information of interest to software developers such as how to design software that will take advantage of this technology.

Until then, happy recording!

- Richard Fricks, Program Manager, Windows Sound Team

10 Things - Volume Mixer

Nick White — Tue, 28 Aug 2007 16:05:00 GMT

Our "10 Things You May Not Know About Windows Vista" series continues as we explore one of the least-known features in Windows Vista: the Volume Mixer. Although it might not be as well-touted as the Aero interface, you may find it's one of the more useful features available.

I'm sure we've all had the experience of working on one application when another application's sound suddenly blasted out your speakers. It can be disconcerting anytime, embarrassing when it happens during a meeting and downright painful when using headphones.

Windows XP had a single control for all sounds, and this controlled only the hardware. If an application's sound was louder or softer than that specified by Windows XP's volume control, you had to constantly adjust the volume.

Windows Vista allows you to choose the right volume for any running application. It's also very easy to use. Right-click the speaker icon in the notification area (systray) of your desktop, then click Volume Mixer to open the control. You'll see a list of programs running. Then, just use the slider bar to adjust the volume up or down. (Note: If some of the sliders have a black background, just move the slider and Windows Vista will re-draw it. KB article 938308 explains this more.)

You can adjust volume for use with either speakers or headphones simply by selecting the desired output in the device column. You can also choose to mute individual programs so as to not be interrupted by sounds from other running programs. If you change the output device, you will need to readjust the volume.

Audio Improvements in Windows Vista

JimAll — Thu, 07 Dec 2006 00:10:00 GMT

A few weeks ago I wrote about the new sounds of Windows Vista and I made the point that sound is an important component of your experience using a Windows PC. As important as the new sounds are as an interface to the Windows UI, of equal importance is the system infrastructure that enables you to control and enjoy those sounds.

I personally use a Windows PC in three ways: 1) at work or at home for productivity, 2) at home (and when I travel) to enjoy media including music, videos and photos, and 3) at home in my recording studio (long story, but the short version is that my mom was glad when I got a real job with this computer science stuff). In all of these situations, having great control over the sounds on a Windows PC is important and prior to Windows Vista it was harder to do.

Imagine you are on a plane writing a document or reading email using Microsoft Office while listening to music stored on your laptop using Windows Media Player. You are listening to your favorite tunes at high volume and suddenly you make a mistake which causes Windows to give you an error sound. On Windows XP, there wasn’t really much you could do about it since there was a single volume control for all sounds generated on the PC -- whether they came from Microsoft Word or Windows Media Player. This is just not a problem on Windows Vista because we have replaced the old Volume Control with the new Volume Mixer. To bring up the Volume Mixer, click on the "speaker" icon in the right side of the tray and select "Mixer," and you will not only see the master volume control for each output device, but also a volume control for each software application -- in this case each application is treated as its own input. The best part is that you can mute the sounds from each application to suit your needs.

While we have made many improvements in Windows Media Center for Windows Vista, these new capabilities become really compelling with great support for high-end audio. So, in addition to making it easier to manage sound in the productivity scenarios, we have also introduced new audio functionality including features and performance that you typically get in a high-end audio/visual receiver, including Room Correction and Bass Management. Together, these new capabilities make Windows the platform for enjoying digital content -- whether you are doing it on a laptop or desktop, in your living room or in your home theater. With these improvements, a PC running Windows Vista with the appropriate sound hardware is the best integrated source of high-end audio and visual content. Here’s why.

Have you ever been watching TV and suddenly an ad comes on that is much louder than the show you were watching? Or, have you ever been listening to the radio and then switched to a CD and had everything get much quieter? The reason for this is that while most audio devices allow you to control the volume of the source, they do not allow you to control its dynamic range. Additionally, most dynamic range solutions in use today aim to maintain a constant signal level, but what your ears perceive is loudness. So for Windows Vista, we added Loudness Equalization which uses an understanding of human hearing to reduce perceived volume differences. The result is that when you change audio sources, the level of loudness that you hear remains much more constant. Some receivers have this feature today, but if you make Windows Vista the source for your digital content in your living room or home theater, you will "just get it" in software, regardless of the capabilities of your A/V receiver.

Windows Vista also includes capabilities to help you get the most of your sound system as well. For example, if you have a high-end multi-channel speaker setup with front and rear channels, a center channel and a sub-woofer, Windows Vista's Speaker Fill feature can be configured to take a standard 2-channel (stereo) source (e.g., a typical music CD) and create a virtual multi-channel experience to help you get the most of your loudspeaker investment. The opposite is also true -- if you don’t have a sub-woofer, a feature called Bass Management can be used to redirect the subwoofer signal to the main speakers. Or, if you are missing a center channel (or maybe you only have the front three channels), a feature called Channel Phantoming allows you to make best use of the speakers that you have.

Whether you have a multi-channel or stereo sound system in your home theater or living room, Windows Vista also includes the ability to calibrate your speakers for your room. By placing a microphone where you plan to sit and then running a wizard that measures the room response, Windows Vista can automatically set the levels, delay and frequency balance for each channel accordingly for this position.

Finally, back to my airplane example. We know that a lot of people enjoy music, movies and TV on their PCs using headphones. With Windows Vista we have added the ability to have surround sound using a new feature called Headphone Virtualization, which uses a technology known as Head-Related Transfer Functions or HRTF. Essentially the system uses information about the physics of your head to create an outside-of-the-head experience. As a result, in addition to hearing the normal sensation of left-to-right sound separation, Windows Vista can also enable the user to differentiate between front and rear sounds as well as close and far sounds. Pretty cool, huh?

The best part of all of this is that you don’t have to be an audio engineer to use this (although I bet a lot of audio engineers will like it). Instead, it's all very accessible using the new audio control panel in Windows Vista. You have to have the right hardware for the enhancements to show up, but a lot of new machines will come with the right stuff.

While in the past, Windows PC and Windows Media Centers were thought primarily as a single source of audio content, with the enhancements in Windows Vista, my expectation is that Windows will become more of an integrated source of content if not more of the receiver/pre-amp in more sophisticated systems -- and, of course, a better way to simply enjoy content on desktop and laptop systems.

I know I can hear the difference.

jim

The Sounds of Windows Vista

JimAll — Fri, 10 Nov 2006 02:15:00 GMT

When you try the RTM version of Windows Vista, you will notice that something changed between the last release candidate and the final product -- we added new sounds to the 45 places where Windows provides an audio cue to the user, including a new Windows Vista Start-up sound that was developed in collaboration with musician Robert Fripp.

If you have used Windows Vista, one of the most significant things you've likely noticed is the new Windows Aero interface. While Windows Aero may sound like just a cool name, it's actually an acronym that stands for Authentic, Energetic, Reflective and Open. Prior to RTM, the Windows Aero experience was intentionally incomplete. What was missing were the cool new sounds that were designed specifically for the Windows Aero experience. While the Windows XP sounds were appropriate at the time Windows XP was built, they were very 'Western' and literal (e.g., you could tell that the sounds were played by a piano and other western orchestral instruments). The Windows XP sounds were not consistent with the interface design goals of Windows Vista, so we overhauled the sounds to complement and blend with the softer, cleaner Windows Aero Glass theme and user interface elements for Windows Vista.

Sounds are obviously an important part of how people interact with their PC. The idea is to use your ears to get information from a sound without even thinking about it. For example, certain sounds on our PC tell us when we have a new email or instant message.

It was our goal for the sounds to be just noticeable enough that if they weren’t there you would miss them, but they’re subtle enough that they don’t get in your way. Just like the visual cues of the new Start button, the audio cues of the new sounds are "rounded" and "translucent." The default sound scheme in Windows Vista is intentionally much gentler and softer than in previous versions.

While I have personally been involved in the Windows Vista sound project for some time, the new sounds were only recently added to the builds (we had to save some surprises for people!), so I have only been experiencing them for a few weeks. What is amazing to me is how much the new sounds change my experience -- and I know it will do the same for you!

jim

P.S. -- here are a few interesting facts about the new Windows Vista Start-up sound.

The Windows Vista Startup sound:

is made of dual ascending 'glassy' melodies played on top of a gentle fading Fripp 'AERO' Soundscape
has two parallel melodies played in an intentional "Win-dows Vis-ta" rhythm
consists of 4 chords, one for each color in the Windows flag
is ~4 seconds long, end-to-end
is a collaboration between contributors Robert Fripp (primary melody + Soundscape), Tucker Martine (rhythm) and Steve Ball (harmony and final orchestration)
would never have been possible without the great work of Microsoft's Steve Ball and his team. There’s an interview with Steve airing tomorrow morning (November 10, 2006) on NPR radio (we’ll post a link when it's available), if you’d like to hear more about these new sounds and the process of generating them.

Update on Ability to Mute the Windows Vista Start-up Sound

Nick White — Sat, 23 Sep 2006 02:01:00 GMT

We heard you loud and clear when it came to discussing our plans to include a default start-up sound that plays as you boot-up Windows Vista: you said you wanted to have the opportunity to mute it if and when you felt it necessary. Your collective voice truly made a difference in this matter, as we've incorporated a way for users to turn off the start-up sound when it's more appropriate to boot silently -- be it when you're mobile, at home or in the office.

Here's a shot of the control panel that will allow you to enable/disable the start-up sound: